chemistry in biology a very brief overview of chemistry chapter 6.2 – 6.4 15 clicker questions!
TRANSCRIPT
ElementElement: Substance consisting
entirely of one type of atom.
Examples: Carbon, Hydrogen, Oxygen
SubscriptA subscript is a small lowered
number after a symbol for an element.
H2O– the 2 is lowered and considered
a subscript.
The 2 indicates how many atoms of the element are present in that compound.
Chemical Compounds
Compound: A substance formed by the chemical combination of 2 or more elements in definite proportions.
Examples: H2O (water) NaCl (Salt)
C6 H12 O6 (Sugar)
Chemical Formula States how many atoms are in each molecule.
How many carbon atoms are in C6 H12 O6?
How many hydrogen atoms?
How many oxygen atoms?
66
1212
66
Click for answers
Chemical Equations Let’s say I give you a chemical equation like—
CO2 + H2O -------- C6 H12 O6 + O2
What are the names of these compounds?
Could you tell me which side are the reactants and which side are the products?
REACTANTS PRODUCTS
Carbon
dioxideWater Sugar/glucose Oxygen
Click for answers
Click for answers
Elements in the Human Body
Oxygen – 65% Carbon – 18.5% Hydrogen – 9.5% Nitrogen – 3.3% All of these equal 96.3%. The other 4% are
trace elements: Calcium (1.5), Phosphorous (1.0), Potassium (0.4), & others.
Water
Most abundant element in our body
Most abundant compound in our body
Click for animation
Clicker Question #1
Which of the following is an element?
a. Carbon dioxide
b. Methane
c. Oxygen
d. Water
Clicker Question #3
Which of the following are the reactants?
CH4 + 2 O2 CO2 + 2 H2O
a. CH4 + 2 O2
b. CO2 + 2 H2O
c. CH4 + 2 H2O
d. None of the above
Solvent-Solute Water is the greatest solvent in the world!
Solvent means to dissolve, or a dissolving
agent. WATER is a SOLVENT!
Solute is what is to be dissolved. Sugar and salt are solutes and they dissolve in water.
pHpH: The measure of concentration of H+ in a
solution.
Acid: Substance that release hydrogen ions (H+) when dissolved in water.
Base: Substance that releases hydroxide ions (OH-) when dissolved in water.
pH ScaleThe pH scale measures how
acidic or basic a substance is.
It ranges from 0 to 14
A pH of 7 is neutral
A pH less than 7 is acidic
A pH greater than 7 is basic
AcidsAcids taste sour
Strong Acids are dangerous and can burn your skin
Examples are: Vinegar, stomach acid, and citrus fruits
Bases Solutions containing bases are often called alkaline.
Bases taste bitter
Bases feel slippery
Strong bases are very dangerous and can burn your skin
Examples: Lye and ammonia
Oven cleaner
Bleach
Ammonia solution
Soap
Sea water
Human blood
Pure waterMilkNormal rainfall
Acid rain
Tomato juice
Lemon juice
Stomach acid
Neutral
Incr
ea
sing
ly B
asi
cIn
cre
asi
ngly
Aci
dic
14 = Basic
0 = Acidic
7 = Neutral
pH Scale
pH QuestionAn ecologist is testing rainwater. She
tests rainwater on the south side of town and finds that the pH is 6.2. Then she tests the north side of town and finds that the pH is 6.8. Which is more acidic?
6.2 is correct!Click for answer
Buffers Buffers are weak acids or bases that can react
with strong acids or bases to prevent sharp, sudden changes in pH.
(Don’t need to write this)
For example, your stomach is upset, so you drink alka seltzer or eat a Rolaids. These are buffers or a mild base to offset the higher stomach acid.
Clicker Question #4
Which of the following is a solute?
a. Water
b. Sugar
c. Vinegar
d. Carbon dioxide
Clicker Question #7
Gastric protease works best in which type of pH?
a. Neutral
b. Basic
c. Acidic
d. All of the above
Clicker Question #8
Which of the following is a solvent?
a. Water
b. Sugar
c. Vinegar
d. Carbon dioxide
Organic MoleculesThere are 4 organic molecules
– Carbohydrates– Lipids– Proteins– Nucleic Acids
* These are also called macromolecules
CarbonCompounds
includes
that consist of that consist of that consist of that consist of
Macromolecule Concept Map
Macro means LARGE
YES,
draw this!
CarbohydratesCarbohydrate: Organic compound
containing Carbon, Hydrogen, & Oxygen with a ratio of 1:2:1
Carbohydrates are basically sugars and starches.
***Most of an organisms’ energy come from carbohydrates!***
Carbohydrates Continued
Monosaccharides are simple sugar molecules.Examples: This is glucose, galactose, sucrose and fructose (sugars).
Glucose is
1 : 2 : 1
Many monosaccharides together make up polysaccharides. This is the excess sugar that we store as glycogen that can turn into fat
6126 OHC
Write these Video Questions & answer them while you watch the video clip.
1. Sugars belong to a class of chemicals called ___.
2. What is glucose made-up of?
3. What is a good example of a very long polymer of glucose called ___.
4. Starches are nothing more than very long chains of ____.
CarbonCompounds
includes
that consist of that consist of that consist of that consist of
Macromolecule Concept Map
Macro means LARGE
Lets fill in the chart!
Carbohydrates
Sugars & Starches
Major source of energy for the body
LipidsThis is FAT.
Lipids: these are used to store energy.
They are found in cell membranes.
Fats, oils, & waxes
Also water proofs
Video
Saturated & Unsaturated Fats
Saturated Fats– Chemical compounds that have a chain of carbon
atoms linked together by single bonds.
Unsaturated Fats– Chemical compounds that contain carbon-carbon
double or triple bonds.
Unsaturated Fats
Unsaturated fats tend to be liquid at room temperature due to kinks in the carbon chain resulting from the double or triple bonds.
These fats are called oils and are also present in fish and plants.
Saturated Fats
Saturated fats tend to be solid at room temperature.
Examples are butter, dairy products, and the fat found in meat.
Health Considerations
Saturated fats are considered unhealthy in excess because they are known to raise “bad” cholesterol (LDL), leading to heart disease, stroke, and other problems.
Unsaturated fats are considered healthier because they raise “good” cholesterol (HDL).
CarbonCompounds
includes
that consist of that consist of that consist of that consist of
Macromolecule Concept Map
Macro means LARGE
Lets fill in the chart!
Carbohydrates
Sugars & Starches
Major source of energy for the body
Lipids
Fats & Oils
Stores energy & water proofs
Nucleic AcidsMade up of Carbon, Hydrogen, Oxygen,
Nitrogen, & Phosphorus
Nucleic acids store and transmit hereditary or genetic information.
Nucleic Acids Continued
Nucleotides consist of a 5 carbon sugar, a phosphate group and a nitrogen base.
2 types: Deoxyribonucleic Acid (DNA)
& Ribonucleic Acid (RNA)
Video Questions:
1. Nucleic acids are made up of long chains of subunits called ____.
2. Chromosomes contain huge molecules called deoxyribonucleic acid also known as ___.
CarbonCompounds
includes
that consist of that consist of that consist of that consist of
Macromolecule Concept Map
Macro means LARGE
Lets fill in the chart!
Carbohydrates
Sugars & Starches
Major source of energy for the body
Lipids
Fats & Oils
Stores energy & water proofs
Nucleic Acids
Nucleotides
Stores & Transmits
Genetic Info
Clicker Question #9
Which of the following is NOT a macromolecule?
a. Carbohydrate
b. Lipid
c. Salt
d. Nucleic acid
Clicker Question #10
Which of the following foods is NOT an example of a carbohydrate?
a. Sugar
b. Potatoes
c. Bread
d. Meat
Clicker Question #11
Genetic material is made with this macromolecule:
a. Nucleic acid
b. Lipid
c. Protein
d. Carbohydrate
Clicker Question #12
Which of the following is NOT a sugar?
a. Glucose
b. Sucrose
c. Lactose
d. Pepsin
ProteinsProteins are composed of smaller units called
amino acids.
Amino Acids: Are small compounds that are made of carbon, nitrogen, oxygen, and hydrogen.
ProteinsActivation Energy: The minimum
amount of energy needed for reactants to form products in a chemical reactions.
Proteins
A catalyst, as well as an enzyme, is a substance that lowers the activation energy needed to start a chemical reaction.
* Catalysts speeds up chemical
reactions thousands of
times faster.
ProteinsEnzymes are biological catalysts that speed up
the rate of chemical reactions.
* Enzymes are made of proteins.
Example: Amylase found in saliva.
Amylase speeds up the breakdown of amylose, a substance in starch (in foods).
* Most enzymes are specific to 1 reaction
Proteins: How enzymes work
Substrate: The reactants that bind to the enzyme.
Active Site: The specific location where a substance binds to an enzyme.
* The active site and the substrate have complementary shapes (“Lock & Key”)
Click on picture to see an animation!
Proteins: How enzymes work
• Only substrates with the same size and shape as the active site will bind to the enzyme (like puzzle pieces).
• pH and temperature mainly affect enzyme activity.
Click on picture for link
Enzymes
Denature – to change the shape of an enzyme so that it no longer works, usually due to a sudden change in pH or temperature
Pepsin: An Enzyme
Pepsin is an enzyme in the
stomach that begins the digestion of proteins by splitting them into smaller pieces.
Pepsin works at a pH level of around 2 which is acidic
Antacids are used to neutralize pepsin by increasing the pH level to around 6 or 7
CarbonCompounds
includes
that consist of that consist of that consist of that consist of
Macromolecule Concept Map
What does MacroMacro Mean?
Lets fill in the chart!
Carbohydrates
Sugars & Starches
Major source of energy for the body
Lipids
Fats & Oils
Stores energy & water proofs
Nucleic Acids
Nucleotides
Stores & Transmits
Genetic Info
Proteins
Amino Acids
Growth/ repair & make up
enzymes
Clicker Question #13
Enzymes are which type of macromolecule?
a. Lipids
b. Carbohydrate
c. Proteins
d. Nucleic Acids
Clicker Question #14
What do enzymes do during a reaction?
a. Nothing
b. Slows it down
c. Speeds it up
d. Burns it up
Clicker Question #15
What two conditions change how enzymes work?
a. Water & temperature
b. Temperature & pH
c. Solid & gas
d. None of the above