Amino Acids and Proteins

Question 1

3 Major Groups of Amino Acids

Answer 1

-non-polar
-polar
-electrically charged amino acids

Question 2

2 types of electrically charged amino acids

Answer 2

acid and base

Question 3

end of amino acid that has an unbound amino group

Answer 3

amino terminus (N-terminus)

Question 4

end of amino acid that has unbound carboxyl group

Answer 4

C-terminus

Question 5

peptide bond

Answer 5

bond between the C in the COOH of one amino acid and N in the NH2 of the next amino acid

Question 6

primary structure

Answer 6

-sequence of amino acids in a polypeptide chain determined by gene that encodes for that protein

Question 7

Secondary structure

Answer 7

1. a helix
2. B pleated sheets
   H bonding of the peptide backbone causes the amino acids to fold into repeating pattern

Question 8

a helix

Answer 8

-often on the exterior of protein and involved in interactions with other molecules
-H bonds between every 4th amino acid

Question 9

common types of tertiary interactions

Answer 9

1. Hydrophobic interactions: amino acids with nonpolar, hydrophobic R groups cluster together on the inside of the protein, leaving hydrophilic amino acids on the outside to interact with surrounding water molecules.
2. disulfide bridges: - covalent linkages between the sulfur-containing side chains of cysteines
   - act like molecular “safety pins,” keeping parts of the polypeptide firmly attached to one another

Question 10

protein consisting of more than 1 amino acid chain

Answer 10

quarternary structure

Question 11

Ways to Represent a Protein

Answer 11

1. ribbon model of lysozymes
2. space-filling model of lysozyme

Question 12

ribbon model of lysozymes pros and cons

Answer 12

Pros
- very good at showing the secondary structure
- show functional units of protein

Cons
-can’t show us a realistic representation of what this protein looks like