Proteins

Question 1

Protein Functions

Answer 1

1. Catalytic
2. Structure (cytoskeleton)
3. Transport
4. Mobility
5. Immunity
6. Communication

Question 2

Primary structure

Answer 2

Amino acid sequence

• chain formed via dehydration rxn
• peptide bonds- stabilized by resonance
• substitutions have varying effects (sickle cell)

Question 3

Secondary structure

Answer 3

H-Bonds in backbone

• alpha helix - R-groups on outside
• Beta sheets
  
  • parallel - N-termini on same side
  • antiparallel- N and C termini together
• Nonregular: Bonds, loops, and turns

Question 4

Tertiary structure

Answer 4

Folded 3D structure

• side chain rxns
  
  1. H-bonds
  2. Hydrophobic interactions
  3. Disulfide bonds
  4. Ionic interactions
• domains independent of each other

Question 5

Quaternary structure

Answer 5

Association of individual subunits

• homo = same subunits
• Hetero = different subunits

Question 6

Protein structures

Answer 6

1. Globular
2. Fibrous
3. Transmembrane

Question 7

Denaturation

Answer 7

1. Nonenzymatic modifications
   * glycosylation
   * oxydation
   * nitrosylation
2. High temps
3. pH