Protein structure

Question 1

What is a protein?

Answer 1

Group of organic compounds of one or more amino acid chains

Question 2

What is the structure of an amino acid?

Answer 2

Carbon with H, amino group, carboxyl group and R group attached
20 different R groups dictate the different amino acids

Question 3

How are amino acids joined in 1° structure?

Answer 3

Joined by condensation reactions between the carboxyl group and the amino group to form a peptide bond

Question 4

What types of bond combine to stabilise formation of a protein?

Answer 4

Covalent bonds
Steric hinderance
Hydrogen bonds
Van der Waal forces
Ionic interactions
Hydrophilic/hydrophobic interactions

Question 5

How are amino acids organised in 2° structure and with which bonds?

Answer 5

α helix
β pleated sheet
Stabilised by hydrogen bonds between -ve O on C=O and +ve H on N-H

Question 6

Which amino acid will put a kink in the α helix?

Answer 6

proline

Question 7

What is electrophoresis?

Answer 7

Method of analysing molecules based on their charge, by measuring their migration in an electric field

Question 8

How can proteins with single mutations be separated by electrophoresis depending on their individual mutations?

Answer 8

If a charged amino acid is substituted for a non charged/differently charged amino acid or vice versa, the protein will be less or more attracted to the positive terminal than the original protein