Structure

Question 1

Define primary

Answer 1

Linear sequence and no of a.a residues in a polypeptide chain

Question 2

Define secondary

Answer 2

Cooling and pleating of polypeptide chains, stabilised by H. bonds between peptide linkages

Question 3

Define tertiary

Answer 3

Coiling and folding of a polypeptide chain into its unique 3D conformation

-4types of bonding between R-groups

Question 4

Define quandary

Answer 4

Association of 2 or more polypeptide chain into one functional complex protein molecules

Question 5

Formation of peptide bond

Answer 5

carbonyl gp linked to amino gp via condensation rn;

forming dipeptide

Question 6

Define alpha helixes

Answer 6

2’ struct’ of a polypeptide that is a helical coil;

stabilised by H bonds bt every 4th peptide bond;

bt O of C=O group and H of N-H group of aa that is four residues ahead

Question 7

How many aa in every turn of the alpha helix?

Answer 7

3.6 amino acid residues per turn

Question 8

Describe the R group of a.a in a-helix

Answer 8

project outside the helix;

perpendicular to the main axis of the polypeptide backbone

Question 9

Define beta pleated sheet

Answer 9

2’ struct of protein formed when a single polypeptide chain folds back and forth;

two regions of the polypeptide chain lie // to each other

Question 10

Two forms of beta pleated sheet

Answer 10

1. //

2. anti-//

Question 11

beta pleated sheet is stabilised by?

Answer 11

intrachain H bond bt C=O and NH groups