WLHS / Biology / MonsonName Period

BIOCHEMISTRY WS #1 – CARBOHYDRATES!WATER:

Examine the chemical formula for water, H2O. H represents the element Hydrogen. O represents the element Oxygen. The number 2 represents the number of atoms of Hydrogen. A number called a subscript, following a chemical symbol indicates the number of atoms of that particular element. No subscript indicates that there is only one atom. The number in front of the chemical formula or the coefficient indicates the number of molecules. No coefficient indicated that there is one molecule present. A molecular formula shows the total number of atoms for each element in the molecule. The molecular formula for water is H2O. A structural formula attempts to show the 3-D arrangement of the molecules.

1) The lines represent bonds between atoms.

2) The structural formula for water is:

3) Properly label the polar molecule with its positive & negative ends. CARBOHYDRATES: (Color the molecules involved with carbohydrates according to the color code.) Carbohydrates contain three different elements: Carbon (C), Hydrogen (H), and Oxygen (O). There are many different types of carbohydrates. They have been placed into three groups — Monosaccharides, Disaccharides, and polysaccharides.

A. Monosaccharides (single molecule sugars)Three examples of monsaccharides are glucose, fructose, and galactose. Examine the structural formulas for these three sugars.

1. What are the 3 elements that are present in glucose, fructose, and galactose?

, ,

2. How many carbon atoms are present in a molecule of:

a. glucose _________

b. fructose _________

c. galactose_ ________

3. Write the proper molecular formula for each monosaccharide. Do this by counting the total number of Carbon, Hydrogen, and Oxygen atoms in each molecule.

a. glucose C___H___O___

b. fructose C___H___O___

c. galactose C___H___O___

The prefix “mono” means one. Monosaccharides are sugars that are made up on only one molecule. Thus, they are called single sugars. The one molecule, however, can have different shapes due to a different arrangement of atoms. Compare the structural formula of glucose and fructose.

4. Are glucose and fructose exactly the same shape?

5. Are glucose and fructose both monosaccharides?

B. Disaccharides (double molecule sugars)Two monosaccharide sugar molecules can join together chemically to form a larger carbohydrate molecule called a double sugar, or disaccharide. The prefix “di” means two. By chemically joining glucose molecule with a fructose molecule a double sugar called sucrose is produced.

Cut out glucose and a fructose paper model. Cut along the solid lines only. In order to join these molecules, you must remove the —OH end from one molecule and a —H end from the other. Cut along the dotted lines. Tape or glue these models onto a sheet of unlined white paper and name the molecule formed.

6. The OH and H ends that were removed can also fit together to form a molecule of H2O. What is the name of this molecule?

Tape this molecule onto the white paper next to the molecule of sucrose.

7. Write the molecular formula for sucrose by adding the molecular formulas for glucose and fructose together and then subtracting the water.

Formula for glucose C___H___O___

Formula for fructose + C___H___O___

Formula for water - H___O___

Formula for sucrose = C___H___O___

Joining other Monosaccharides in different combinations can make different disaccharide molecules. By chemically joining a glucose molecule with another glucose molecule, a double sugar maltose is formed.

Cut out and attempt to join two glucose molecules together. (cut along solid lines only)

In order to join the molecules, remove an —OH end from one molecule and an —H end from another. Cut along the dotted lines. Place these models on your sheet of unlined paper and name the molecule.

8. How many monosaccharides are needed to form one sucrose molecule?

C. Polysaccharides: (many molecule sugars)Just as double sugars were formed from two single sugar molecules, polysaccharides are formed when many single sugars are joined chemically together. The prefix “poly” means many. Starch, glycogen, and cellulose are the three most common polysaccharides in biology. They consist of long chains of glucose molecules joined together.

Construct a starch molecule by joining three glucose molecules together. This will represent only a small part of a starch molecule because starch molecules consist of hundreds of glucose molecules joined together.

In order to join the molecules, remove an —OH from one molecule and an —H from another molecule. Tape or glue these models on your unlined white paper and label the molecules formed (starch & water).

BIOCHEMISTRY WS #2 – FATS!FATS: (Color the molecules involved with carbohydrates according to the color code.)To better understand the chemistry of fats, it is helpful to first study the small molecules that join to make up fats. Fat molecules are made up of two different kinds of chemical molecules. These are glycerol and fatty acids.

A. Glycerol:

Examine the structural formula of glycerol.

1. What elements are present in glycerol?

B. Fatty Acids:The second kind of molecule, which is part of a fat, is a fatty acid. Many different fatty acids exist but all are similar in several ways. Butyric acid, caproic acid, and lauric acid are a few examples. Examine the structural formulas of the three molecules below.

2. What elements are present in all fatty acids?

3. What is the molecular formula for butyric fatty acid?

4. What is the molecular formula for lauric fatty acid?

5. What is the molecular formula for caproic fatty acid?

A fat molecule consists of one (1) glycerol and three (3) fatty acid molecules joined together.

Cut out the glycerol and fatty acid paper models. Cut along the solid lines only. Attempt to construct a fat molecule.

6. Will the fat molecule fit together like pieces in a puzzle?

**Remove the three —OH ends from the glycerol molecule and the three —H ends from the fatty acids. Now join the molecules to form a fat and place them on your unlined paper. Label it.

7. How many fatty acid molecules are needed to form a fat molecule?

Join the all the left over OH and H ends to form water molecules. Tape them down on your unlined paper. Label it.

The production of a fat molecule is a chemical reaction. A chemical shorthand way of expressing the formation of a fat is as follows:

Glycerol + 3 fatty acid molecules = fat + 3 water molecules

Many fats exist in living things. Different combinations of fatty acid molecules form the wide varieties of fats.

8. What molecule stays the same in fats?

BIOCHEMISTRY WS #3 – PROTEINS!PROTEINS: (Color the molecules involved with carbohydrates according to the color code.)Proteins are complex molecules made up of simpler building blocks called amino acids. Examine the structural formulas of the four amino acids shown below.

The element Nitrogen (N) is present in amino acids.

1. Is Nitrogen present in fats and carbohydrates?

2. What is the molecular formula for the amino acid glycine?

3. What is the molecular formula for the amino acid alanine?

4. What is the molecular formula for the amino acid threonine?

5. Are all the molecular formulas for all amino acids the same?

On one end of each amino acid, there is an of a Nitrogen atom and two Hydrogen atoms. This group is called an amino group.

6. Do all structural formulas of amino acids have the amino group?

A protein is composed of many amino acids joining together chemically.

Cut out four amino acid models. Cut along the solid lines only. Attempt to join the amino acids.

7. Will the protein molecule fit easily together like puzzle pieces?

**Join the molecules by removing as many OH and H groups as needed from the amino acids. All four molecules can be joined together in this manner to form a protein.

Join them in this order: Valine — Threonine — Alanine -- Glycine**Rejoin the left over OH and H ends to form water molecules. Tape all molecules on to your unlined paper and label them.8. How many molecules of water are formed when four amino acids join together?

Chemists express the joining of these amino acids as follows:

Val + Thr + Ala + Gly Protein + 3 H2O molecules

ANALYSIS QUESTIONS:1. Name the three categories of biological molecules studied in this investigation.

2. What three elements are found in carbohydrates, fats, and proteins?

, ,

3. Give the names of the three monosaccharides studied

, ,

4. Give the names of the two disaccharides constructed.

,

5. Which polysaccharide did you make?

6. What are the building blocks needed to make a large fat molecule?

,

7. What are the building blocks needed to make a large protein molecule?

8. In building ALL of these large biological molecules, you had to remove –OH and –H atoms from the building blocks before joining them together. Which compound is produced when you join –OH to –H??

!

**Assemble all completed molecules from the cutout paper models. Tape them onto a piece of plain, white paper, and LABEL all molecules (including any water molecules produced!)

**Attach completed models to this packet.