Proteins 1

Question 1

What does protein function depend upon

Answer 1

3D Structure

Question 2

Primary Structure and what is included

Answer 2

Amino Acid sequence, including disulfide bridge

Question 3

Secondary Structure

Answer 3

Local packing/regular occurring arrangements of polypeptides

Question 4

Tertiary Structure

Answer 4

3D Packing of secondary structure elements

Question 5

Quaternary Structure

Answer 5

Number & position of polypeptide subunits

Question 6

Alpha carbon

Answer 6

“main” carbon in an amino acid (bonded to NH2 and COOH)

Question 7

N Terminal

Answer 7

Amino acid in protein with full amino group

Question 8

C Terminal

Answer 8

Amino acid with full carboxyl group

Question 9

Cysteine vs Cystine

Answer 9

Cysteine has not formed disulfide bond while Cystine has done so

Question 10

Steric clash

Answer 10

Unnatural overlap of two non-bonding atoms in a protein structure that leads to slowing of chemical reactions

Question 11

Which amino acid form is favoured (Trans or Cis)

Answer 11

Trans is favoured as there is no steric hindrance

Question 12

φ (phi) bond

Answer 12

N-Cα Bond

h from phi looks like a lower case n

Question 13

ψ (Psi) bond

Answer 13

Cα-COOH Bond

Question 14

What are the torsion/dihedral angles

Answer 14

Angle formed by ψ and φ bonds in an amino acid

Question 15

Difference in hydrogen bonding between alpha helices and beta sheets proteins

Answer 15

In alpha proteins, hydrogen bonds are between amino acids close to each other in primary sequence, but in beta this applies to amino acids close in 3D space

Question 16

Domain

Answer 16

Independent units of function in a protein

Question 17

What does protein breathing allow?

Answer 17

It allows small molecules to enter a protein