Select the correct answer.
1. The 20 different amino acids are distinguished by:
a. location of carboxyl groups
b. location of amino groups
c. "side chain" or "R group" composition
d. ability to form peptide bonds
2. Which of the following choices are FALSE? Some of the most important functions of proteins includes their ________
a. role as biological catalysts (enzymes)
b. role as transport molecules
c. preferential use over carbohydrates and lipids as a source of energy
d. role in cell movement
3. Which of the following statements about condensation reactions is NOT true.
a. They play a role in protein synthesis
b. They play a role in polysaccharide synthesis
c. Different condensation reactions produce different kinds of macromolecules.
d. They consume water as a reactant.
4. Look at fig. 3.2 in your textbook (fig 3.3 in the 4th edition) or slide 2 of lecture 7. This figure shows the structure of all 20 amino acids found in organisms. Consider the amino acids histidine, glutamic acid, threonine and leucine. Suppose all of these were part of a protein. Which of them would most likely?
a. Interact well with lipid?
b. Which would interact best with the R-group of the amino acid Aspartic acid?
c. Which (more than one answer) could interact well with water?
5. Draw a short peptide composed of three different amino acids. Label the C terminus and N terminus and indicate the position of the peptide bonds. Place partial charges on the terminal groups. Which of your three amino acids would be (a) most and (b) least likely to form hydrogen bonds with water molecules.
6. No matter how large or complex a protein may be, its underlying structure can be broken down into just four basic levels of organization. What simple names do we give to these four levels of structure?
1. "Side chain" or "R group" composition.
2. Preferential use over carbohydrates and lipids as a source of energy.
3. They consume water as a reactant.
4. Interact well with lipid?:Leucine.
Which would interact best with the R-group of the amino acid Aspartic acid?: Histidine.
Which (more than one answer) could interact well with water?: Histidine, glutamic acid and threonine.
5. Cysteine >> Glycine > Alanine
6. Primary, Secondary, Tertiary, and Quarternary.