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Name ____________________________________

Initial Ideas for Thursday, September 2 For the first 5 minutes of class, please answer the following questions on your own. If you’re not sure, give it a guess! These are your initial ideas – you can correct your thoughts later or add to them during our discussion. In order to get credit, you must write down something!

1. What is science?

2. What is biology?

3. What does it mean to do science?

Science starts with __________________________

Theory Cube: What will be on the 6 th side of the cube? Science starts with a question. In order to answer that question, we make observations.

2 SIDES SHOWING 3 SIDES SHOWING 5 SIDES SHOWINGObservations:

Hypothesis:

Predictions (for unknown sides):

Observations:

Hypothesis:


Observations:

Hypothesis:


What do YOU think will be on the 6th side of the cube? What makes you think that?

Author, 01/03/-1,

This needs to be changed/streamlined somehow. Is the point here to get them to know the difference between a hypothesis and a prediction, or rather to use observations to generate a model to describe an unknown?

Initial Ideas: What do organisms need to survive? On the lines below, describe what organisms (living things) need to survive.

Directions: On the map below, draw and label anything you observe.

Shed

Grass

Trees

Grass

Grass

Grass

Trees

Trees

Trees

Definitions:

Biotic:

Abiotic:

Using your map from the nature walk, categorize what you saw as biotic or abiotic using the T-chart below:

Abioticnever been alive

BioticAlive Dead

Name ______________________________________

Exit Slip: Thursday, Sepetember 2 Pick one living organism you observed today during the nature walk. What did that organism need to survive? Where did it get those things? Label each thing as biotic or abiotic.

You need to write the information for AT LEAST 3 before you leave for lunch today.

Requirement for survival Source Biotic or abiotic?

Name ______________________________________

Exit Slip: Thursday, Sepetember 1 Pick one living organism you observed today during the nature walk. What did that organism need to survive? Where did it get those things? Label each thing as biotic or abiotic.

You need to write the information for AT LEAST 3 before you leave for lunch today.

Requirement for survival Source Biotic or abiotic?

Name ______________________________________

Initial Ideas for Friday, Sepetember 3 What do plants take from the environment? Fill out the table below with at least 3 examples, but I encourage you to list more. Additionally, in the final column, mark with an “X” if it is essential for plant growth.

Taken from environment Source (be specific about where it comes from and how it gets into the

plant)

Biotic or abiotic?

Essential for growth?

What is essential for bean growth? You will be designing and doing an experiment to find out what is essential for a bean plant to grow. I will give you a slip of paper telling you which of those things plants take from the environment that you will test.

Write down your experimental question below:

Is ____________________________ essential for bean plant growth?

In the space below, draw a picture of your experimental set up. Label everything!

What will you measure?

What do you predict will happen in each of the treatments in your experiment? Why?

Fill in the column headings below. You will take data each day when you enter class.

Date Additional observations

Once I have checked your table and experimental design, you may go to the lab and set up your experiment!

Name ______________________________________

Exit Slip: Friday, Sepetember 3 1. Why did you set up two bean cups to test your variable?

2. Why is it important that you change ONLY ONE thing between the two cups?

Name ______________________________________

Exit Slip: Friday, Sepetember 3 1. Why did you set up two bean cups to test your variable?

2. Why is it important that you change ONLY ONE thing between the two cups?

Name ______________________________________

Initial Ideas: Tuesday, Sepetember 7 You’ve heard the saying, “You are what you eat.” Do you agree with this statement? Why or why not? Use examples from your own personal life and diet.

What makes up the food we consume? Imagine eating a pizza with all the works. Also, imagine if you could ‘see’ all the food molecules that make up that pizza just after it entered your mouth. Those molecules might look like what you see in the figure below

At this point you can think of food molecules as very small (submicroscopic) bits of substances that make up food. We will present a more formal definition of molecules later.

Group the molecules that you see in the figure into 2 to 4 groups (based on any criteria that you would like) and then fill in the table below

Group Molecules in group

What are the characteristics that the molecules in this group have in common?

A

B

C

D

In the table below list differences (if any) among molecules within each particular group.

Group Differences, if any, within group

A

B

C

D

FOOD MOLECULESSugar and starch are components of a broader group of molecules called carbohydrates. Sugars are often called simple carbohydrates because they are relatively small and have relatively simple chemical structures. One sugar that is typically found in our blood (as well as in our food) is glucose. Its simple chemical structure is often represented as a hexagon. Other common sugars are sucrose (table sugar) and fructose.

What substance(s) in Figure 2-1 might be a sugar molecule? Number _________

What is your evidence?

Sugars, particularly glucose, are often linked together like boxcars in a train to form molecules like starch. Starch is typically hundreds to thousands of glucose molecules linked together. Long chained molecules like starch are often called complex carbohydrates. Simple carbohydrates and complex carbohydrates are the two major subdivisions of carbohydrates.

What two types of molecules in Figure 2.1 might be called complex carbohydrates. What is your evidence?

What is the same about the two types of molecules?

What is different?

Cellulose is made up of long chains of glucose, hence it is also considered a complex carbohydrate. However, the bonds holding the glucose molecules together in cellulose are different than those found in starch. Nutritionists sometimes simply refer to cellulose as fiber.

The complex carbohydrate with the curve bars linking the glucose molecules is how we represent cellulose in Figure 2-1. The curved bars used to show that glucose molecules are bonded differently in cellulose than in starch. What molecule in Figure 2-1 represents cellulose? Number _________

The complex carbohydrates with glucose molecules linked together without the curved bars represents starch. What two molecules in Figure 2-1 represent starch molecules? Numbers __________ and _________.

Proteins are another major component of food. They are composed of smaller subunits called amino acids. Unlike complex carbohydrates, which are made up thousands of only one type of sugar (glucose) linked together, proteins are made up of hundreds of several different types of amino acids. There are actually twenty different types of amino acids.

Which large molecule in Figure 2-1 do you think represents proteins? Numbers _________ and _________. What is your evidence?

The final major component of food that has been recognized are fats and oils. Fats and oils are greasy feeling and, do not mix well with water and are chemically very similar. Fats are solid at room temperature whereas oils are liquid at room temperature. Unlike complex carbohydrates and proteins, fats and oils are medium sized molecules made up of four smaller subunits. Three of the four small molecules are almost identical and are called fatty acids. These three molecules are each linked to the fourth molecule called glycerol. Which medium sized molecules in Figure 2-1 represent fats or oils? Numbers _________,_________,_________ and _________.

Scientists have found that over ninety-five percent of almost all foods are composed of carbohydrates, proteins, and fats.

How does the scientists grouping of food molecules compare to the grouping of food molecules that you suggested at the beginning of class (go back to your original table)?

On what basis were you grouping different types of food?

On what basis did scientists divide food molecules?

Name ______________________________________

Exit Slip: Tuesday, Sepetember 7 1. What are the three major groups of food molecules recognized by scientists? How are these molecules similar to

each other?

2. How do these molecules differ from each other?

3. What are the two major subdivisions of carbohydrates? What is the distinction between the two major subdivisions?

4. How are cellulose and starch similar?

5. How do cellulose and starch differ?

Name ______________________________________

Exit Slip: Tuesday, Sepetember 7 1. What are the three major groups of food molecules recognized by scientists? How are these molecules similar to

each other?

2. How do these molecules differ from each other?

3. What are the two major subdivisions of carbohydrates? What is the distinction between the two major subdivisions?

4. How are cellulose and starch similar?

5. How do cellulose and starch differ?

Name ______________________________________

Initial Ideas: Thursday, September 8 1. Which of the following molecules qualify as food? Place a check next to each one.

___ Proteins___ Minerals___ Carbohydrates___ Water

___ Vitamins___ Carbon dioxide___ Oxygen___ Fats

How did you decide which molecules are food and which are not? Use examples from your own life to explain your answer.

2. Using your notes, what do carbohydrates, fats, and proteins look like? For molecules that are made of multiple parts, label the subunits, or parts. Fill out the table below:

Molecule Type Drawing

Glucose

Starch

Cellulose

Fat

Protein

What is food made out of?

Scientists have been able to determine the chemical composition of the foods we eat. The following table lists the composition of several common foods.

Food Water (%) Carbohydrate (%)

Protein (%) Fat (%) Vitamins and Minerals (%)

Coca cola 90 10 <1 <1 <1Marshmallow 16 75 9 <1 <1Ground beef, lean 56 <1 25 19 <1Chicken breast 62 <1 30 8 <1Corn 70 26 3 1 <1Beans, refried 74 19 6 1 <1Banana 75 24 1 <1 <1Peanuts 1 22 25 48 <1Steak 54 <1 27 18 <1Broccoli 88 8 3 <1 <1Twinkie 26 60 2 12 <1Oreo 6 71 3 20 <1Kit-Kat bar 3 61 7 29 <1

1. Based on the table above, what do you think is the chemical composition of most plants? In other words, what molecules are plants mostly made out of? What is your evidence?

2. Based on the table above, what do you think is the chemical composition of most animals? What is your evidence?

Scientists have also looked at the chemical composition of an average human. The following this data:

Water (%) Carbohydrate (%)


Average Human 58 1 14 22 5

3. What do you think composes most of the Vitamins and Minerals category?

The following is the composition of an average human if you were to exclude bones:

Water (%) Carbohydrate (%)


Average Human 50 1 15 23 <1

4. Once we exclude bones from the calculation of chemical composition of humans, what four types of molecules constitute 99% of the human body?

5. How does this compare to the chemical composition of food?

6. Go back to your Initial Ideas from Tuesday. How does what you just looked at change your answer to the question of whether or not “You are what you eat”? Use evidence (data) to explain your response.

How does food help us grow? How do you think organisms use the food they eat grow (become larger in size)?

Which of the following do you think are mainly responsible for helping organisms to grow? Put a check next to each one.

___ Simple carbohydrates

___ Complex carbohydrates

___ Fats

___ Proteins

___ Vitamins and minerals

___ Water

How did you make your decision what to put check marks by? Use examples from your own life to explain your answer.

COLLECTING DATA

The data for the different time intervals were recorded and illustrated in the Time 0 through Time 4 diagrams. Observe the changes in location and appearance of the molecules of food for each time interval. Record your observations in the table below. Be sure to use the appropriate vocabulary! You should be using words such as glucose, starch, cellulose, protein, amino acid, fat, fatty acid, glycerol.

Time Interval Observations

Time 0 – Time 1

Time 1 – Time 2

Time 2 – Time 3

Time 3 – Time 4

Count all the subunit molecules that are part of the large molecules originally present in the mouth at Time 0. Record your results in the table below.

Count all the subunit molecules at Time 4 in the blood, the typical cell, and the fat cell whether they are ‘free’ or connected together to form larger molecules, and put your results in the table below.

Group Number of subunits at time 0 Number of subunits at time 4

Did you account for all the building blocks? If not, what was missing? Where did it go?

Summarize what happened to the molecules that originally entered the mouth over the time period between Time 0 and Time 4.

SUMMARIZE THE DATA

Molecule picture Name Subunit (smaller part) In the cell, become part of what larger

molecule?

DIGESTION AND GROWTH

In the diagrams, you observed that the larger molecules were broken down into subunits before being reassembled in cells. This breakdown facilitates two processes.

1. Distribution

For food molecules to pass from the small intestine to the blood vessels, the food must first pass through the cells that line both the small intestine and blood vessels. The digestive process that goes on in the stomach and small intestine facilitates this transfer by making the molecules small enough to pass more easily into and out of cells.

Cellulose (molecule #3) is a major constituent of plant cell walls that can’t be digested by most animals. What this demonstrates is that not all carbon sources can be used for food. Approximately 50% of our waste (feces) consists of cellulose and other undigestible food products and 50% consists of dead bacteria which once lived in the digestive tract.

Some microorganisms that live outside our bodies can ‘digest’ cellulose. Into what subunits might these microorganism be able to digest cellulose? Explain your reasoning.

2. Reassembly The breakdown of larger molecules into subunits also facilitates the reassembly of new molecules which are needed for growth and maintenance of organisms’ bodies. Sometimes the main function of these reassembled carbohydrates, proteins and fats is to make the structure of the organism. Other times these newly assembled molecules serve mainly as storage materials for later use within the organism. For example, when plants need more structure they assemble sugar molecules to make cellulose. However when they simply want to store carbohydrates they assemble the glucose subunits into starch.

Animals rarely build their structure out of carbohydrates. They use mostly proteins. They do, however, store sugar molecules in long chains like plants do. This long chained molecule is composed of subunits very similar to starch, but it is called glycogen.

We have not mentioned glycogen previously because it is only a minor constituent of food. Though we store glycogen it never makes up more than about 1.5% of our total body weight. This is typical for almost all animals. Plants, on the other hand, especially certain plant organs like potato tubers can store large quantities of starch.

SUMMARIZING QUESTIONS

1. Describe how the glucose subunits that compose starch (in say spaghetti) can end up as part of glycogen in one of your cells.

2. What happens to cellulose in our digestive tract?

3. What happens to a fat molecule in our digestive tract?

4. What typically happens to amino acids once they arrive in a cell?

5. Refer back to your answer to the question “How do you think organisms use the food they eat grow (become larger in size)?” Have your ideas changed? Now that you have more information, answer the same question below as completely as you can.

YOUR TURN

Pick up one of the meals from the front of the room. In the space below, draw a diagram showing how that food moves from your mouth into your cells (or out of your body as waste – keep it school appropriate!). Be sure to show all the different components of food.

Meals:

Peanut Butter and Jelly Sandwich

Fat Starch Simple sugars Fiber Protein11 grams 23 grams 13 grams 5 grams 11.5 grams

Taco Bell Beef Taco

Fat Starch Simple sugars Fiber Protein10 grams 11 grams 1 gram 3 grams 8 grams

Big Mac

Fat Starch Simple sugars Fiber Protein29 grams 34 grams 9 grams 3 grams 25 grams

Snickers

Fat Starch Simple sugars Fiber Protein9 grams 2 grams 15 grams 1 gram 3 grams

Peanut Butter and Jelly Sandwich

Fat Starch Simple sugars Fiber Protein11 grams 23 grams 13 grams 5 grams 11.5 grams

Taco Bell Beef Taco

Fat Starch Simple sugars Fiber Protein10 grams 11 grams 1 gram 3 grams 8 grams

Big Mac

Fat Starch Simple sugars Fiber Protein29 grams 34 grams 9 grams 3 grams 25 grams

Snickers

Fat Starch Simple sugars Fiber Protein9 grams 2 grams 15 grams 1 gram 3 grams

Name ______________________________________

Exit Slip: Friday, September 10 1. A potato contains starch but no glycogen. A muscle has glycogen but no starch. Explain how this

happens.

2. Go back to the data tables that show the chemical composition of food. What is in food that wasn’t included in the molecule maps? Do you think this counts as food? Why or why not?

3. Which of the following do you think are mainly responsible for helping organisms to grow? Put a check next to each one.

___ Simple carbohydrates

___ Complex carbohydrates

___ Fats

___ Proteins

___ Vitamins and minerals

___ Water

4. How would you define food, given what we have looked at for the last two days?

Name ______________________________________

Initial Ideas: Monday, September 13 1. Look at the poster at the front listing how you originally defined food (from Thursday, September 8th Initial

Ideas). Do all of those things contribute to an organism’s growth? Which ones are listed that don’t contribute to growth? (Remember watching Martin Jr. grow last week!).

2. Look at the sentences at the bottom of the poster. They aren’t quite right! How would you write the definition of food?

3. You have probably heard the word “matter” in other courses. How would you define matter?

4. Give three examples of things that you might consider as matter.

Formal Definition of Matter:

What is the chemical nature of small molecules? If food is an example of matter and food is made up of molecules, what are molecules themselves made of? What gives molecules their mass or weight? It turns out that all molecules are made of atoms. In fact all matter is ultimately composed of atoms. It is the atoms themselves that give matter its mass or weight.

Atoms can come in a variety of forms. Gold, silver, oxygen, uranium, iron, sodium, and hydrogen are all examples of different types of atoms. Carbohydrates and fats are made up almost entirely of only three different types of atoms: carbon (C), oxygen (O) and hydrogen (H). A fourth type of atom, nitrogen (N), is also needed along with carbon, oxygen and hydrogen to make proteins. Individual atoms by themselves are often unstable and tend to become more stable by forming chemical bonds with other atoms.

1. What atoms are carbohydrates made of?

2. What atoms are fats made of?

3. What atoms are proteins made of?

When two or more atoms form chemical bonds with each other, the result is a molecule. For example, when two hydrogen atoms bond with an oxygen atom, the result is a water molecule. Water can be written in short hand as H2O which signifies that one oxygen atom is bonded to two hydrogen atoms. This chemical formula tells you the type of each atom making up the molecule and the number of each type of atom making up the molecule.

4. What does the chemical formula CO2 tell you about the molecule? PART 1: BUILDING SMALL MOLECULES

Oxygen

If two atoms have two or more holes, then they can form two or more bonds with each other. Try bonding two oxygen atoms together. Notice, when oxygen bonds with another oxygen with just one bond, a hole is left in each of the two oxygen balls. This is an indication that you have not constructed a stable molecule. What would happen if you tried to connect the two oxygen atoms with two bonds? To do this you must use another spring. Try bonding two oxygen atoms together in this manner.

1. Do you think you have created a stable molecule? What is your evidence?

2. Why would you call what you have constructed a molecule?

3. Draw your O2 molecule.

You have constructed molecular oxygen or O2. This is the form in which most oxygen in air is found. We call O2 molecular oxygen so as not to confuse it with a single atom of oxygen.

4. Would a single atom of O be stable? What would be your evidence?

When we breathe in oxygen we are actually breathing in O2 not individual oxygen atoms. Single atoms of O would be quite unstable and tend to form bonds with other atoms to become more stable.

Carbon Dioxide

Using the rules that we have been discussing for making stable molecules, try making carbon dioxide or CO2. (1 Carbon, 2 Oxygen)

Does your newly constructed molecule have any extra ‘holes’ in the atoms? If so, keep trying until you have built a molecule consisting of one carbon and two oxygen atoms with all holes filled.

5. Draw your molecule of CO2.

Carbon dioxide is the molecule that we breathe out.

Water

Now let’s make water or H20. (2 Hydrogen, 1 Oxygen)

6. Did you need double bonds or single bonds to make water?

7. Draw your molecule of H2O.

Name:_______________________________

Exit Slip: Monday, September 13 1. How can you tell if a molecule is stable?

2. What atoms are in water? How many of each?

3. What atoms are in carbon dioxide? How many of each?

Name:_______________________________

Exit Slip: Monday, September 13 1. How can you tell if a molecule is stable?

2. What atoms are in water? How many of each?

3. What atoms are in carbon dioxide? How many of each?

Name:_______________________________

Initial Ideas: Tuesday, September 14 1. What does the C in CO2 represent?

2. How many hydrogen atoms are in H2O?

3. What molecule does this shape represent?

4. The molecular formula for glucose is C6H12O6. What atoms do you think glucose is made out of? How many of each type?

5. If you were building a molecule of glucose using the molecule kits, how could you tell if it was a stable molecule?

What is the chemical nature of glucose? PART 2: MAKING GLUCOSE

You have made several of the small molecules essential for life to exist (H20, CO2, and O2). Now we are going to construct some more complicated molecules. We will first construct some important carbohydrates.

Let’s start by constructing the simple carbohydrate glucose. The chemical formula for glucose is C6H12O6.

1. Glucose would therefore be a molecule that consists of: ____ carbon atoms (C)

____ hydrogen atoms (H)

____ oxygen atoms (O)

To arrange the atoms in the proper configuration to make glucose, follow along with the instructions on the slides.

2. How many hydrogen atoms did you use in making this glucose structure? _______

3. How many carbon atoms did you use? _______

4. How many oxygen atoms did you use? _______

5. Is this consistent with the molecular formula (C6H12O6) of glucose? ___________

6. Does the structural model of glucose that you made appear to be a stable molecule? ___________

7. What is your evidence?

8. Draw your glucose molecule

What are some ways we represent atoms and molecules? As you noticed while creating glucose with the molecular model kits, it is challenging to draw these structures. We have different ways of representing the same molecules, depending on what we are trying to show. The following table summarizes the different representations scientists use:

Type of representation

How are atoms of glucose represented?

How are molecules of glucose represented?

How are molecules (macromolecules) of starch represented?

Ball and stick

= carbon= oxygen= hydrogen

3-dimensionalphysical balls

Structural formula C = Carbon

O = OxygenH = Hydrogen

Chemical formula C = Carbon

O = OxygenH = Hydrogen

C6H12O6 C24H42O21

Cartoon diagram

not usuallyrepresented

Each representation has benefits and limitations. Depending upon your purpose for representing a molecule at a particular time, you may want to use a different representation. Choose which representation you would use in the situations described below.

1. If you want to count the number of carbon atoms in a starch molecule to compare it to another molecule, which representation(s) would be most helpful to use?

2. Which representation(s) would be least helpful?

3. If you are describing what happens to starch in your digestive system and want to draw some diagrams to support your description, which representation(s) would be most helpful to use?

4. If you wanted to see where oxygen atoms are located in a molecule of glucose, which representation(s) would be most helpful to use?

5. Which representation(s) would be least helpful?

6. If you wanted to show the general shape of a molecule but didn’t need to keep track of individual atoms, which representation(s) would be most helpful to use?

Name:_______________________________

Exit Slip: Tuesday, September 14

1. List three molecules that you have made today and yesterday. Chose any representation you want. Explain why these are considered molecules.

2. What do you think are the three atoms that make up the majority your body?

, ,

3. Where do you think these atoms come from?

Name:_______________________________

Exit Slip: Tuesday, September 14

1. List three molecules that you have made today and yesterday. Chose any representation you want. Explain why these are considered molecules.

2. What do you think are the three atoms that make up the majority your body?

, ,

3. Where do you think these atoms come from?

Name:_______________________________

Initial Ideas: Thursday, September 16 1. What atoms make up a molecule of glucose? How many of each?

2. What atoms make up a molecule of starch?

3. Fill in the blanks in the following table:

1 glucose molecule 2 glucose molecules 3 glucose molecules 4 glucose moleculesNumber C atoms 6 12Number H atoms 12 24Number O atoms 6

4. Using the structural formula of starch shown below, count how many C, H, and O there are. (Remember, if you see H2, that counts as 2 H atoms)

C = ______

H = ______

O = ______

5. Compare your counts of C, H, and O from the starch molecule above to the number of C, H, and O in 4 glucose molecules from the table. How are the counts similar? How are the counts different?

6. The four atoms that make up the majority of your body are carbon (C), hydrogen (H), oxygen (O), and nitrogen (N). What were those atoms a part of before they became a part of you?

What is the chemical nature of starch? On Tuesday, you created a molecule of glucose using the molecule kits. Creating a molecule of starch using the molecule kits becomes quite challenging, so instead, we will be using the structural formula to build starch.

First, let’s remember how many bonds each atom needs to make in order to be stable.

1. How many bonds does hydrogen (H) need to make to be stable? ______2. How many bonds does oxygen (O) need to make to be stable? ______3. How many bonds does carbon (C) need to make to be stable? ______

Look at the structural formula of glucose in front of you. One of the oxygen atoms as a next to it, while one of the carbon atoms as a next to it.

4. How many bonds does the oxygen atom with a next to it currently have? _____5. How many bonds does the carbon atom with a next to it currently have?_____

Cut along the dotted line on the left side of one molecule (removing the H) and along the right side of the other molecule (removing an OH). This leaves both the oxygen and carbon atoms marked with shapes unstable, as well as the hydrogen and oxygen that were removed unstable.

Without putting the pieces back together the way they were, see if you can combine the different pieces to make a stable molecule of starch.

6. Draw the cartoon diagram (using hexagons only) to draw the molecule you created.

7. What did you do with the H and OH you removed? What molecule can they form?

8. How do you think that you could bond another glucose molecule to your two glucose chain?

9. In plants what two complex carbohydrates could this long molecule represent?

10. In animals what complex carbohydrate would this long molecule represent?

Fat Molecule

What is the chemical nature of fat? The structural diagram below shows a molecule of fat:

Using the structural formulas you have of glycerol and fatty acids, see if you can create the molecule shown above.

1. In what ways is the bonding of fatty acids to glycerol to make fat similar to the bonding of glucose molecules together to make starch?

Fats are broken down to 3 fatty acids and glycerol in a similar way that the chain of glucose molecules in starch are separated into individual glucose molecules.

2. Are the types of atoms making up a fat molecule the same as the types of atoms making up carbohydrates?

3. If they are the same, what are these atoms?

4. If there are one or more different types of atoms, what are they?

Amino Acids

Bonded Amino Acids

What is the chemical nature of protein? The structural formulas below show two different amino acids.

1. What is similar about amino acid a and amino acid b in the picture above? You can mark on the pictures above if that would be easier to show similarities and differences.

2. What atoms are used in making amino acids? Are these the same as in fats and carbohydrates?

Look at the structural formula below of two amino acids bonded together. Using your amino acids, see if you can link them together in a similar way.

3. When these amino acid molecules are bonded together, what type of molecule do they form?

4. In what way is the bonding of amino acids similar to the bonding of glucose molecules to make starch?

Summarizing questions: Chemical Nature of Food 1. List three molecules that you made in this activity. Explain why these are considered molecules.

2. List three things discussed in today that you might consider matter. Explain why these would be considered matter.

3. Why do you think our digestive tract can break down starch and glycogen, but it cannot break down cellulose?

4. What is needed to break fats, proteins and carbohydrates down in our bodies?

How do we keep track of matter moving through a body? We have now seen that food can be thought of as matter, just like any object that takes up space and has weight. We also know that all matter including food is made up of atoms. In addition, we know that the carbohydrates and fats are made up specifically of carbon, oxygen, and hydrogen atoms. And proteins are made up of carbon, oxygen, hydrogen, and nitrogen atoms. Scientists are often interested in what happens to these various types of atoms in ecosystems over time. By following what happens to these atoms as they move through ecosystems, scientists are essentially following what happens to matter as it moves through ecosystems.

As the various types of atoms don’t always stay bonded together in the same molecules, it is generally easier to focus on one type of atom at a time. Although at times we will be interested in all four types of atoms CHON we will most commonly focus on carbon in this course. If we don’t count the water that makes up almost 70% of our bodies, carbon is the most common type of atom in our bodies. This is true for nearly all organisms.

So let’s go back to our person who had just taken a bite out of a pizza and see what happened to the carbon atoms in their food as the food went through the combined processes of ingestion, digestion and circulation.

In the digestive tract, food molecules were broken down in their respective building block molecules.

More specifically, carbohydrates were broken down into ___________,

fats were broken down into_________________ and ________________,

and proteins were broken down into__________________.

To summarize, we might say that carbon has been transferred from the environment to the cells of our bodies as a result of the combined processes of _____________, ______________, and _________________.

MATTER DIAGRAMS

We will use what we call ‘matter diagrams’ to help visualize how carbon moves in, through, and out of organisms (and eventually in, through, and out of ecosystems). In the matter diagrams, we can keep track of where specific food molecules are coming from, where the molecules go, and what the molecules get rearranged to form.

Source (location):Mouth

Carbon containing molecule:

Starch

Receiver (location):Stomach/small intestine


Starch

Source (location):Stomach


Starch

Receiver (location):Stomach/small intestine


Source (location):Stomach/small intestine


Receiver (location):


In the matter diagram below, we can track where starch in a potato goes. It starts in the mouth as starch and moves into the stomach. When the starch in the potato first reaches the stomach, it is still starch.

What happens next to that starch? The starch will stay in your stomach and small intestine for a little while. What molecule does the starch change into? You try to fill in the blank of the following matter diagram:

What happens next to that molecule? Try filling out the next step of the matter diagram:

Martin Jr. ate some pasta. In that pasta is starch. Using the matter diagram cards, trace the path a carbon atom would take from being a part of a molecule of starch in a noodle to being a part of a molecule of glycogen in one of his cells. Then fill in the diagram below.

Now “translate” your matter diagram into sentences. Describe in complete sentences how an atom of carbon goes from being part of a molecule of starch in pasta to part of a molecule of glycogen in a cell.

Cell

Glucose

Stomach/ Small Intestine

Glucose

Mouth

Starch

Blood

glucose

Cell

Glycogen

Stomach

Starch

PastaStarch

Are you made of corn? In the first 5 minutes of the film “King Corn”, Ian and Curt find out that the carbon in their bodies comes primarily from corn even though they do not eat a lot of fresh or canned corn. How does that happen? Create a diagram showing how an atom of carbon that originally came from corn becomes part of a hair cell even though they ate a steak (not corn on the cob). Then explain your answer in complete sentences.

Name:_______________________________

Initial Ideas: Friday, September 17

1. Go back to the back page of yesterday’s packet. If you didn’t write your answer in complete sentences, do that first. Then turn the packet into me.

2. Draw a matter diagram showing the movement of a carbon atom that is part of a fat molecule in butter into a fat molecule in a fat cell in your body. Assume the carbon atom you are tracing is in the glycerol building block of the fat molecule.

3. Describe the matter diagram you drew above in complete sentences.

4. Jared “The Subway Guy” weighed 425 pounds while he was a student at Indiana University. After unsuccessfully attempting numerous diets, Jared grabbed a nutritional information brochure at his local Subway restaurant and started a reduced calorie diet by eating two Subway submarine sandwiches a day.

In a year’s time, and by incorporating exercise into his daily routine, Jared lost 245 pounds.

Where did those 245 pounds go? (Don’t share your answer with your neighbor! I want to know what YOU think!)

What happens to the food molecules after we absorb them? So far we have focused on how food adds mass or matter to living organisms. But what else is food used for? Refer back to the poster we made when we first tried to define food. What aspect of food have we not discussed yet?

COLLECTING DATA

Last week we looked at the processes of digestion and absorption using the molecule maps and Martin Jr. Imagine if every molecule Martin Jr. ate other than cellulose became a part of him. He would be huge! So clearly, the story doesn’t stop there.

Look at the molecule maps for Time 4 through Time 6. Write down your observations in the table below:

Time Interval Observations

Time 4 – Time 5

Time 5 – Time 6

1. You noticed that some of the molecules seemed to disappear. Which ones?

2. What do you think happened to them? What evidence do you have for this explanation?

Marshmallow

Glucose

What happens when sugar burns? You noticed that glucose seemed to disappear from the cells between Time 4 and Time 6. In order to find out what happened to them, we will look at what happens when we burn marshmallows (which are composed mostly of sugar like glucose) when we burn them.

PROCEDURE

1. Place a large marshmallow onto the vertical wire on the stand.

2. Place the stand and marshmallow on the balance and tare the balance (set it to zero).

3. Using the lighter, light the marshmallow until it starts to burn. Keep burning it with the lighter until it is completely burned.

4. Note the change in weight of the marshmallow: ______

ANALYSIS

1. What happened to the mass of the marshmallow as you burned it?

2. Let’s pretend for the moment that the marshmallow is pure sugar (it almost is), then the marshmallow would be made up of millions and millions of sugar molecules. What do you think happened to millions of sugar molecules when you burned the marshmallow?

3. Draw a matter diagram showing what you think happened to the carbon atoms during the burning of the marshmallow.

Name _____________________________

Where did it go?

What molecule did it become a part of?

Exit Slip: Friday, September 17 1. Which molecule “disappeared” in Time 4 through time 6?

2. What atom(s) does the burned marshmallow have less of now?

Name _____________________________

Exit Slip: Friday, September 17 1. Which molecule “disappeared” in Time 4 through time 6?

2. What atom(s) does the burned marshmallow have less of now?

Name _____________________________

Initial Ideas: Tuesday, September 21

1. List 3 things you eat that contain carbon atoms from corn but don’t have corn in the name.

2. A non-biology question, but important all the same! What sorts of things might lead to getting a yellow slip?

3. What does it mean when you get a yellow slip?

4. What does it mean to treat each other with respect?

Go back to your packet from Friday and open to the page called “What happens when sugar burns?”

What happens to the air around the marshmallow when it burns? 1. If you could see the gas molecules in the jar before burning the marshmallow, which ones do you think

you would see? (Remember, a molecule is 2 or more atoms combined)

2. When we tried to burn the marshmallow in the jar, the flame went out. Why do you think that happened?

3. If you could see the molecules in the jar after burning the marshmallow, which ones do you think you would see?

Because it is impossible to see the molecules of gas, we use probes to detect what gases are present in the container and what concentration they are in. We will use these probes to monitor how the concentration of O2 and CO2 change while the marshmallow burns.

DATA COLLECTION: OXYGEN

O2 concentration (%)

Initial

Final

ANALYSIS QUESTIONS

1. What happened to the oxygen concentration of the air surrounding the burning marshmallow? Describe what happened using data and approximate times.

2. What do you think happened to the oxygen?

3. It seems that the oxygen disappeared and the sugar disappeared. Did anything seem to appear during the burning of the marshmallow? Examine the chamber carefully. What do you think this is?

Cobalt chloride paper can be used to detect the presence of water. It turns pink when it comes in contact with water molecules.

DATA COLLECTION: WATER

Color of paper

Dry

In contact with tap water

In the collection bottle

ANALYSIS QUESTIONS

We now have evidence that sugar and oxygen seem to have ‘disappeared’ during the burning of the marshmallow. We also have evidence that water appeared as the result of burning sugar. When sugar burns, the bonds that hold the two oxygen atoms together in the oxygen molecule (O2) and the bonds that hold the carbon, hydrogen and oxygen atoms together in the sugar molecule (C6H12O6) actually break, and the atoms rearrange themselves into new molecules. We have evidence that at least some of the hydrogen and oxygen atoms might have formed water molecules. What atom(s) still need to be accounted for if the atoms in sugar and oxygen molecules did indeed rearrange themselves into new molecules?

Marshmallow

Glucose

We still haven’t accounted for where the carbon atoms went when we burned the marshmallow. One possibility is that they became part of CO2 molecules in the air.

DATA COLLECTION: CARBON DIOXIDE (CO2)

CO2 concentration (%)

Initial

Final

ANALYSIS QUESTIONS

1. Briefly describe what happens to glucose, oxygen, water and carbon dioxide when a marshmallow burns.

2. Draw the ball and stick model of an oxygen molecule, a water molecule, and a carbon dioxide molecule (glucose has been done for you):

Oxygen Water Carbon dioxide

3. Where did the carbon atom in CO2 come from?

4. Where did the hydrogen atom in H2O come from?

5. Draw a matter diagram tracing what happens to a carbon atom in a glucose molecule when a marshmallow burns:

Name _____________________________

Exit Slip: Tuesday, September 21 1. What molecule is carbon a part of when it enters your body?

2. What molecule is carbon a part of when it is in your cells?

3. What molecule is carbon a part of after the glucose molecule changes into something else?

4. How do you think that molecule leaves your body?

Name _____________________________

Exit Slip: Tuesday, September 21 1. What molecule is carbon a part of when it enters your body?




Name _____________________________

Initial Ideas: Thursday, September 23

1. What molecule is carbon a part of when it enters your body?




What happens to the atoms when sugar burns? After burning the marshmallow and using the probes and test paper, we saw that when a marshmallow burns, the glucose and oxygen decrease while the carbon dioxide and water increase. In fact, for every molecule of glucose that is consumed, 6 molecules of oxygen are consumed, and 6 molecules of each carbon dioxide and water are produced. We summarize this using the chemical equation below:

C6H12O6 + 6 O2 6 CO2 + 6 H2OThe molecules on the left are known as the reactants. They are what you start with. The molecules on the right are known as products. They are what you end up with when the reaction is complete.

COLLECTING EVIDENCEUsing the molecule kit, build the reactants (glucose and oxygen). Remember that you need six molecules of oxygen!

1. How many of each type of atom do you have?

Carbon (black): ______Hydrogen (white): ______Oxygen (red): ______

Using the atoms in your glucose and oxygen molecules (and no others!) make carbon dioxide and water.

2. How many molecules of carbon dioxide (CO2) and water (H2O) were you able to create?

3. Were there any atoms or springs left over? Or did you need to get more atoms or springs?

4. How many of each atom type are in your products:

Carbon (black): ______Hydrogen (white): ______Oxygen (red): ______

When the number of each type of atom is the same for the reactants and the products, we say that the equation is balanced.

5. Describe what happened to the atoms as they went from being reactants to products:

When you have finished looking at the CO2 and H2O molecules, please help and turn them back into C6H12O6 and 6 O2.

SUMMARIZING QUESTIONS

1. A marshmallow was lit on fire inside a chamber and the molecular oxygen (O2) level was monitored. Which graph shows what would happen to the molecular oxygen concentration inside the chamber?

2. Which graph shows what would happen to the levels of CO2 inside the chamber?

3. Which graph shows what would happen to the amount of H2O inside the chamber?

4. Which graph shows what would happen to the number of C6H12O6 molecules inside the chamber?

5. Suppose we could keep track of the number of carbon atoms (the black balls) in the chamber over time. Which graph would show this? Explain your reasoning.

What happens to sugar in our cells? Below are copies of Times 4 through 6. What “disappeared” during these time segments?

Where do you think that molecule went? What evidence do you have?

Inside stomach and small intestine.

Molecules pass through walls of small intestine into blood stream and are carried to cells throughout the body.

In the mouth.

Inside large intestine.

Waste that leaves the body.

Time 4 Cells

throughout the body.

Fat cell

Typical body cell

Bloodstream



In the mouth.



Time 5 Cells


Fat cell

Typical body cell

Bloodstream

In order to determine if what is happening in your cells is similar to what is happening when you burn a marshmallow, we would want to do similar experiments with the probes. Unfortunately, we cannot fit a person in one of our containers. However, we can fit crickets!


Cells



In the mouth.



Time 6Fat cell

Typical body cell

Bloodstream

COLLECTING EVIDENCE

We will set up probes and a container like you see below:

Predictions:1. What do you predict will happen to the levels of O2 in the flask? Why do you think this?

2. What do you predict will happen to the levels of CO2 in the flask? Why do you think this?

DATA COLLECTION:

Oxygen

O2 concentration (%)

Initial

Final

Carbon Dioxide

CO2 concentration (ppm)

Initial

Final

3. Describe in complete sentences what happened to the O2 and CO2 levels in the flask with the crickets.

4. What is the chemical equation describing the process that happened with the crickets?

5. Where in the cricket do you think this reaction is happening?

6. Draw a matter diagram showing what happens to an atom of carbon as it moves from a marshmallow, into a cell in a cricket, back into the air surrounding the cricket. Then describe in complete sentences the path a carbon atom follows from the marshmallow into the cricket and back into the atmosphere.

Marshmallow

Glucose

Cricket’s mouth

Glucose

Cricket’s stomach

Glucose

Cricket’s Blood

glucose

Cricket’s Muscle Cell

Glycogen

Cricket’s Muscle Cell

Glucose

Cricket’s muscle cellGlucose

Cricket’s muscle cell

CO2

Cricket’s blood

CO2

Cricket’s “lungs”

CO2

Atmosphere

CO2

Name _____________________________

Exit Slip: Thursday, September 23 Cellular respiration is the process of converting glucose and oxygen to carbon dioxide and water.

1. Write the BALANCED equation for cellular respiration below (this means that there should be the same number of atoms of each type on both sides of the equation:

_____________ + _____________ _____________ + _____________

2. What evidence did you get today to show that cellular respiration is taking place in animal cells?

3. What do you think is the benefit to animals doing cellular respiration in their cells?

Name _____________________________

Exit Slip: Thursday, September 23 Cellular respiration is the process of converting glucose and oxygen to carbon dioxide and water.

1. Write the BALANCED equation for cellular respiration below (this means that there should be the same number of atoms of each type on both sides of the equation:

_____________ + _____________ _____________ + _____________

2. What evidence did you get today to show that cellular respiration is taking place in animal cells?

3. What do you think is the benefit to animals doing cellular respiration in their cells?

Name _____________________________

Initial Ideas: Friday, September 24 1. What is cellular respiration?

2. How is cellular respiration similar to a burning marshmallow?

3. The marshmallow wasn’t hot when you started burning it, but by the end, even after removing the lighter, the air surrounding the marshmallow was warmer. How do you think that happened?

4. Why do you think the marshmallow stopped burning?

5. When you go for a run, why do you think you get warmer?

How do glucose molecules store energy? Some things burn better than others. For example, glucose burns easily while water does not. Why is this? What is it about fuels that make them burn?

Look at the molecular diagrams of fuels below and determine what they have in common.

1. Burning Methane.

Methane, which makes up about 75% of ‘natural gas’, is used as an energy source to heat your homes, cook food, or generate electricity.

2. Burning butane.

In your classroom, you likely have a butane burner for your chemistry labs. People also often use butane lighters to light things, when they are grilling outdoors or the like.

3. Burning propane.

In the summertime, we often use gas grills to cook hamburgers and hot dogs. Many of the grills and camping stoves use propane fuel.

4. Burning ethanol.

In recent years, there has been increasing publicity and support for using ethanol from corn as a fuel source for our automobiles. Currently, ethanol is mixed with gasoline and burned by engines in our vehicles to run.

6. Burning gasoline

Gasoline is a mixture of hydrocarbons, including heptane (C7H16) and octane (C8H18).

Octane (C8H18)

1. What do all of the fuels above have in common?

2. What do you think would cause one fuel to have more stored chemical energy than another?

3. What types of bonds are in a molecule of glucose? How is this similar to the fuels shown above?

4. Circle the molecule below that you think has more stored chemical energy.

Explain why you chose the molecule you did.

5. The molecule above on the left is glucose while the one on the right is a fat. Glucose has 4 Calories per gram while fat has 9 Calories per gram. Does this information change your answer to question 3 or support it? Why?

6. Draw the molecular structure of water and carbon dioxide.

7. What atoms are bonded in these two molecules? List the different combinations.

8. Do water and carbon dioxide burn? What do you think determines whether or not a substance burns easily?

Glucose

chemical

Environment

Light and heat

Hydrocarbons are molecules with C-C and C-H bonds. They are considered to be energy rich molecules. When you add a little bit of energy (a spark), that breaks the bonds between the C and H atoms, and they rearrange to form lower energy molecules. In the process of forming these lower energy molecules, energy is released.

When glucose burns, the atoms of the glucose and surrounding oxygen molecules rearrange to form carbon dioxide and water. However, at the same time, energy is released.

9. When we burned the marshmallow, what were you able to observe that showed energy was released?

ENERGY DIAGRAMS

We can use energy diagrams to trace how that energy is transferred from one place to another. Energy diagrams are similar to matter diagrams as we will trace the location of energy from one location to the next. To indicate that we are talking about energy, we will use stars instead of cylinders.

The following matter diagram shows the energy transfers that happen when glucose burns. We start with chemical energy in a molecule of glucose, and that energy is transferred to the environment as light and thermal energy.

Location of energy

Type of energy

Glucose

chemical

Environment

Light and heat

MarshmallowGlucose

Environment

CO2

When you look at the matter and energy diagrams together, you can keep track of what is happening to both the atoms as well as the energy. The following are the matter and energy diagrams for burning glucose:

Energy Diagram:

Matter Diagram (tracing carbon):

Above, you can see that while the carbon atoms in the glucose molecule in the marshmallow are rearranged to form carbon dioxide, the chemical energy in that glucose molecule is transferred to the environment as light and heat.

1. Why do you think we trace carbon in the matter diagrams instead of hydrogen or oxygen?

2. What other molecule is needed for glucose to burn?

3. When we burned the marshmallow, was the glucose burning, the oxygen, or both?

Exit Slip: Friday, September 24 1. There are five types of bonds that we see in glucose, oxygen, carbon dioxide and water. List them

below (the first has been done for you):__C - O__ ________ ________ ________ ________

2. Circle the bonds above that are considered to be high-energy bonds. What evidence do you have that those are the high-energy bonds?

3. The following is the chemical equation for the burning of candle wax:C25H52 + 38 O2 25 CO2 + 26 H2O

a. Draw the matter diagram showing what happens to the carbon atoms in candle wax:

b. Draw the energy diagram showing what happens to the energy stored in candle wax:

4. What happened to the candle wax?

5. Did the candle wax turn into the heat or light? What is your evidence?

6. Why do you think you get warmer when you go for a run?

Name ____________________________

Initial Ideas: Monday, September 27 1. List 3 fuels we talked about on Friday (use your notes!)

2. What is it about those fuels that makes them burn? In other words, what is special about the atoms in fuels that make them different from molecules that don’t burn?

3. Candle wax can be considered a fuel. What happens to the chemical energy stored in the wax as the candle burns?

4. What happens to a car that runs out of fuel (gas)? Where did the fuel go?

How do our bodies use fuel? Last week, we saw that when fuels burn, chemical energy stored in the hydrocarbons is released as heat and light energy. However, we know that’s not the only benefit we get to burning fuels. When you drive a car, heat is transferred to the environment, but the real benefit to burning fuel in a car is that it allows your car to move! If it didn’t, your car would be a glorified heater.

Your body also uses food as fuel. How does it do this?

1. List several processes in your body that require energy.

2. Describe any evidence that the processes going on in your body might be similar to what happens when a marshmallow burns.

3. In the processes above, what makes them different from the burning of a marshmallow?

THERMAL ENERGY FROM CELLULAR RESPIRATION1. What is the current temperature of the classroom? _________

2. What is your body temperature? _________

3. What is happening in your body to make your body temperature warmer than the surrounding air? In other words, where is that heat energy coming from?

Environment

thermal

Useful (kinetic)

4. Approximately 60% of the energy released in cellular respiration is in the form of thermal energy. Draw an energy diagram below showing the transfer of this thermal energy into the environment.

5. What is the energy source in cellular respiration? ________________________

6. What type of energy is being transferred from this energy source? _______________________

7. If 60% of energy from cellular respiration is transferred to the environment as thermal energy, how much is still unaccounted for? What do you think this energy is used for?

USEFUL ENERGY FROM CELLULAR RESPIRATION

Clearly there is another benefit to cellular respiration than just keeping warm. You do lots of other things, like moving, talking, thinking, etc. The other 40% of energy from cellular respiration is used for these other activities. We will call this energy “useful” energy as it is used for you to do day-to-day activities.

Let’s consider a muscle cell in your leg. You need energy to “power” the muscle fibers to contract so that you can move your leg. When you do this, some of the stored chemical energy in the glucose in your muscle cell is transformed into useful kinetic (motion) energy in your muscle fibers.

1. Complete the energy diagram below to show the energy transfer to muscle cells:

Muscle Cell

Glucose

2. Where did the energy come from to move the muscle cell?

3. As a reminder, what is happening to the matter during this process? Fill out the following matter diagram:

4. Did the glucose turn into energy to move the muscle cell? What is your evidence?

In your body, there is actually a step between the chemical energy in glucose being transferred to useful kinetic energy in a muscle cell. Instead, your body first uses the chemical energy in glucose to build a molecule called ATP (Adenosine triphosphate) out of ADP (Adenosine diphosphate) and P. When the last P is removed from ADP, the chemical energy in ATP that is released is what is used as “useful” energy.

P P P

P P P

CHEMICALENERGY

INPUTENERGY

FOR CELLULARWORK

OUTPUT

ATP

Useful (kinetic)

5. Fill out the following energy diagram showing the transfer of stored chemical energy in glucose to useful kinetic energy in a muscle cell:

As the useful kinetic energy is used in a process such as a muscle contraction, that kinetic energy is transferred into the surrounding tissues as thermal energy. This is why you get warmer when you exercise. That thermal energy is then transferred to the environment.

6. Draw the energy diagram showing the transfer of stored chemical energy in glucose all the way into the environment as thermal energy:

PUTTING IT ALL TOGETHER: ENERGY IN CELLULAR RESPIRATION

1. How much energy was immediately released to the environment as thermal energy? ______%

2. How much energy was transformed into useful energy? ______%

3. Where was the energy stored to begin with?

4. Where does all the energy ultimately end up?

5. Fill in the energy diagram below showing how chemical energy in glucose is used to move a muscle cell, and eventually ends up in the environment as thermal energy:

6. Describe in complete sentences what the energy diagram is showing:

60%

40%

Name _____________________________

Exit Slip: Monday, September 27 Many of you wrote on your exit slip last Thursday that you thought the purpose of cellular respiration (rearranging the atoms of glucose and molecular oxygen to form carbon dioxide and water) was breathing. Breathing is actually the body’s way of getting more oxygen into your cells for cellular respiration and for getting rid of the carbon dioxide created in your cells from cellular respiration.

However, the act of breathing itself takes stored chemical energy. When you breathe, a muscle called the diaphragm moves up and down to open and close your lungs. Describe how the stored chemical energy in glycogen in a diaphragm cell is transformed to allow you to move the muscle and breathe.

Name _____________________________

Initial Ideas: Tuesday, September 28 1. What kind of energy is in glucose?

2. What kind of energy is released when you move a muscle?

3. What kind of energy does all energy eventually end up as? Where does it go?

4. When a glucose molecule is used in cellular respiration, what happens to the carbon atoms?

5. When a molecule of oxygen (O2) is used in cellular respiration, what happens to the oxygen atoms?

Matter and Energy Diagrams: The Big Picture Use your matter cards to arrange the parts of the matter diagram in order, tracking carbon as it goes from food into a muscle cell and back to the environment. Once you have arranged the cards, fill in the diagram below:

Use your energy cards to arrange the parts of the energy diagram in order, tracking energy as it goes from chemical energy in food (starch) into a muscle cell and back to the environment. Once you have arranged the cards, fill in the diagram below:

You should now have a master matter and energy diagram, tracking how food is used to build structures in your cells and then converted to carbon dioxide and how the energy changes from stored chemical energy, to useful energy, to thermal energy in the environment.

Environment

CO2

Lungs

CO2

Blood

CO2

Muscle

CO2

Muscle

Glucose

MuscleGlycogen

Muscle

Glucose

Blood

Glucose

Stomach/ small intestine

Glucose

Mouth

Starch

Environment

Thermal

Environment

Thermal

Muscle cell

Kinetic

ATP in muscle cell

Chemical

Glucose in muscle cell

Chemical

Glycogen in muscle cell

Chemical

Glucose in muscle cell

Chemical

Glucose in blood

Chemical

Glucose in stomach

Chemical

Starch in mouth

Chemical

Starch in food

Chemical

How do diets work? According to the Center for Disease Control, in 2009, 26.4% of the population of Washington State was classified as obese (as defined by a Body Mass Index (BMI) of 30 or greater1). You probably learned in health class that the best way to combat weight gain is a balanced diet and exercise. How does that help?

Consider the following foods and the stored chemical energy (in Calories) in them:

Food Calories

Snickers 270

Taco Bell Soft Taco -beef 210

Peanut butter and jelly sandwich 300

Big Mac 540

Subway Footlong Turkey Sandwich 580

Now consider the calories for the following activities:

Activity Calories burned

Walk 1 mile (12 minute mile pace) 102

Run 1 mile (8 minute mile pace) 280

Sleeping for 1 hour 57

Working in class for 1 hour 114

Playing soccer for 1 hour 445

1. If you had only eaten a Snickers, you would still be able to play soccer for an hour, but you would probably feel tired. Where does the energy come from for you to play soccer?

2. If you eat a Big Mac and walk 1 mile (12 minute mile pace) what will happen to the molecules with the stored chemical energy that you do not use?

3. When you exercise, are you might not be burning the calories in the food molecules you ate that day. Instead you might be converting the calories stored in the food molecules you ate long ago. Where are these food molecules kept?

1 To calculate your BMI, use the following formula: BMI=703∗weight (lbs)height (¿)2

Summarizing the Unit: What is the function of food for animals? Over the past 4 weeks, we have been investigating the question “What is the function of food for animals?” Each day, you have had a different question at the top of your packet and you have worked through experiments, activities, and readings to answer those questions. It is time to summarize what you have learned from each section.

Using your worksheets, write a brief summary explaining your thoughts for each question. Support your answers with evidence from activities, labs and demonstrations done in class.

1. What makes up the food we consume? What is food made out of? (September 7 and 9)

2. How does food help us grow? (September 9)

3. What is the chemical nature of small molecules (oxygen, carbon dioxide, water)? (September 13) [what atoms are these three molecules made out of?)

4. What is the chemical nature of glucose? (September 14) [what atoms is glucose made out of?]

5. What are some ways we represent atoms and molecules (September 14) [what are the benefits of each?]

6. What is the chemical nature of starch? (September 16) [what atoms is starch made out of?]

7. What Is the chemical nature of fat? (September 16) [what atoms is fat made out of?]

8. What is the chemical nature of protein? (September 16) [what atoms is protein made out of?]

9. How do we keep track of matter moving through a body? (September 16) [draw an example]

10. What happens to molecules after we absorb them? (September 17)

11. What happens to sugar when it burns? (September 17)

12. What happens to the air around a marshmallow when it burns? (September 21)

13. What happens to the atoms when sugar burns? (September 23)

14. What happens to sugar in our cells? (September 23)

15. How do glucose molecules store energy? (September 24)

16. How do our bodies use fuel? (September 27)

Putting the Pieces Together: Jared the Subway Guy Jared the Subway Guy lost 245 pounds over the course of a year when he switched to eating a reduced calorie diet of 2 Subway sandwiches a day.

Go back to your Initial Ideas on Friday, September 17. In question 4, you wrote down what you think happened to the 245 pounds that Jared lost. Many of you said he sweated it out, or it went away when he went to the bathroom.

Given everything we have done in the past week, explain how Jared lost. A complete answer will tell me both about what happened to the matter in Jared as well as why that happened.

Feel free to use matter and energy diagrams, but full credit will only be given to explanations written in complete sentences.

Name : _________________________

How Does a Baby Grow, Move, and Stay Warm? You have been building an understanding on how animals use food. In this activity, you will practice constructing explanations that accurately and completely reflect these ideas. You will be asked to explain what happens to matter and energy in a young baby’s body so that she can grow, move, and keep her body functioning. Each of the questions below can be answered using two types of explanations: an explanation that describes how matter transformed in the body, and an explanation that describes how energy is transformed in the body.

We have completed the first question for you. Notice that we wrote a “matter explanation” and an “energy explanation” that describes what happens in the baby’s body.

Question 1: How does a baby that is eating strained peas get the matter and energy it needs to grow?

Matter Explanation Energy Explanation

The baby digests its food, producing small molecules that travel through the blood to its cells. These cells take up small molecules, such as glucose, and can use these small molecules to build larger molecules needed by the cell. For example, the baby’s cells could use glucose to build glycogen.

The baby digests its food, producing small molecules that travel through the blood to its cells. These molecules have stored chemical energy. The cells take up small molecules, such as glucose, and can burn these small molecules in cellular respiration. During cellular respiration, the stored chemical energy is transferred from small molecules such as glucose to useful chemical potential energy (in ATP) that the baby’s cells can use to power processes for growth.

In this example, the same question was answered two different ways: one explanation focused on the transfer of energy; the other focused on the transfer of matter. Both explanations are correct, and because the question asked how the baby got matter and energy for growth, both explanations are necessary to completely answer the question.

Now consider the following questions and try to write a “matter explanation” and “energy explanation” for each.

Use your “Matter and Energy Diagrams: The Big Picture” to explain what is happening with the matter and energy as a baby does various things. You should focus on specific portions of your matter and energy diagrams that apply to the task being discussed, not the whole thing!

Question 2: A baby is crawling across the floor. In terms of matter and energy, explain what is happening inside the baby’s muscle cells.


Question 3: A baby’s father plays a game of chase with the baby, causing the baby to laugh and crawl fast. As the baby crawls fast and laughs, it is breathing in oxygen and breathing out carbon dioxide. Explain where the carbon atoms in the carbon dioxide come from and how they are released into the air when the baby breathes.


Question 4: When a baby takes a nap, its mother covers it with a light blanket. The air under the blanket becomes warmer than the air in the room, which keeps the baby warm while it is sleeping. Explain how the air around the baby becomes warm while it is sleeping.


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