Tertiary structure of proteins

Question 1

Name the 4 bonds.

Answer 1

Disuphide bridges, ionic bonds, hydrogen bonds, hydrophobic interactions.

Question 2

Disulphide bridges

Answer 2

• found between sulphur atoms in the molecules of amino acid, cysteine.
• covalent bonds, form very strong links, makes tertiary protein structure very stable.

Question 3

Ionic bonds

Answer 3

• occur between any carboxyl and amino groups that have not been involved in forming peptide bonds
• bonds are weaker that disulphide bridges.
• can be broken by the change in pH

Question 4

Hydrogen bonds

Answer 4

• result from attraction between electronegative oxygen

- individually weaker than ionic bonds, makes them an important factor

Question 5

hydrophobic interactions.

Answer 5

-due to certain non-polar R groups in amino acids that have side group which repel water