Lecture 5 (8/18)-Protein Structure

Question 1

All psi and phi bonds are equal

Answer 1

True

Question 2

Alpha helix is a ? handed helix?

Answer 2

Right

Question 3

Distance occupied by 1 AA?

Answer 3

1.5 A

Question 4

Pitch

Answer 4

distance traversed along axis after 1 complete turn

Question 5

What are the helix capping amino acids?

Answer 5

Asn as the N-cap and Histidine as the C-cap

Question 6

Aromatic rings help keep ?

Answer 6

Hydrophobic regions together

Question 7

What holds alpha helices together?

Answer 7

Hydrogen bonds

Question 8

Beta sheet are designed to be?

Answer 8

The scaffolding or skeleton system for a globular protein

Question 9

What allows the peptide chain to reverse direction ?

Answer 9

The beta turn

Question 10

Which amino acids are prevalent in beta turns?

Answer 10

Proline and glycine

Question 11

Myoglobin peptide consists of ? helical segments ?

Answer 11

8

Question 12

Catalytic triad

Answer 12

H-57
A-102
S-195

Question 13

Explain the orientation of the catalytic triad

Answer 13

The Aspartate pulls on the His and the Ser

Question 14

Zinc finger has

Answer 14

Cys-x-x-Cys

Question 15

Regarding quaternary structure, describe the interactions

Answer 15

Noncovalent for globular proteins

Covalent for fibrous proteins

Question 16

What gives the heme group O2 affinity ?

Answer 16

Fe is displaced from the plane of the porphyrin ring due to it being pulled on by His F8