protein structure

Question 1

what holds a-helices in place?

Answer 1

hydrogen bonding between the C=O of one amino acid and the NH2 of another amino acid 4 residues away

Question 2

are a-helices left or right handed?

Answer 2

can be either (hypothetically) however, most are right handed

Question 3

why do peptides exhibit steric hindrance?

Answer 3

the partial double bond character of the peptide bond restricts movement

Question 4

what is a native protein?

Answer 4

a protein in its correct conformation, with the minimum level of free energy

Question 5

name 3 conditions which can cause disruption of a protein

Answer 5

• heat
• changes in pH
• presence of chaotrophic agents

Question 6

how do chaotrophic agents cause denaturation of proteins?

Answer 6

unravel tertiary structure by destabilising internal, non-covalent bonds between atoms

Question 7

why is ribonuclease useful for experimentation?

Answer 7

it can be denatured and renatured fully in vitro