Session 5: Protien Structure

Question 1

What is an amino acid residue?

Answer 1

What remains once an aa is joined via a peptide bond to form a protein

Question 2

How can aa be classified?

Answer 2

• chemical properties

- physical properties

Question 3

Name 7 chemical properties than can be used to classify aa?

Answer 3

1. Hydrophilic
2. Hydrophobic
3. Acidic
4. Basic
5. Neutral
6. Polar
7. Non-polar

Question 4

Name 2 physical properties than can be used to classify aa?

Answer 4

1. Aliphatic

2. Aromatic

Question 5

Aa with a negatively charged R groups (low pKa) tend to be…?

Answer 5

Acidic

Question 6

Aa with a positively charged R groups (high pKa) tend to be…?

Answer 6

Basic

Question 7

What will the result be if the pH of a solution is less than the pK value?

Answer 7

Group will be protonated

Question 8

What will the result be if the pH of a solution is greater than the pK value?

Answer 8

The group will be deprotonated

Question 9

What kind of reaction is peptide bond formation?

Answer 9

Condensation

Question 10

Name 3 key features of peptide bonds.

Answer 10

1. Planar
2. Rigid (partial double bond characteristics)
3. Trans conformation

Question 11

What is the isoelectric point of a protein?

Answer 11

pH at which there is no overall charge

Question 12

Name 3 features of a alpha helix.

Answer 12

1. 3.6 aa
2. 0.54nm pitch
3. Right-handed helix
4. R groups on outside

Question 13

Name 2 aa residues that are strong helix formers.

Answer 13

Ala

Leu

Question 14

Name 2 aa residues that are strong helix breakers.

Answer 14

Pro

Gly