Proteins and levels of protein structures

Question 1

What are the three terminals in an amino acid?

Answer 1

The N terminal, C terminal and the R group.

Question 2

What is another name for the N terminal?

Answer 2

Amino group.

Question 3

What is another name for the C terminal?

Answer 3

Carboxyl group.

Question 4

What is special about the R group?

Answer 4

It varies and makes each amino acid different.

Question 5

What elements do proteins contain?

Answer 5

Hydrogen, Carbon, Oxygen and Nitrogen.

Question 6

What bond does a condensation reaction between two amino acids form?

Answer 6

A peptide bond.

Question 7

Describe the primary structure.

Answer 7

The sequence is determined by the base sequence on one strand of DNA.
It uses peptide bonds.

Question 8

Describe the secondary structure.

Answer 8

It can present as an Alpha- helix or a Beta- pleated sheet.
It uses peptide and hydrogen bonds.

Question 9

Describe the tertiary structure.

Answer 9

When a secondary Alpha-helix structure is twisted further to make a complex 3D structure.
It uses peptide, hydrogen, ionic and disulphide bonds. It also involves hydrophobic interactions.

Question 10

Describe the quaternary structure.

Answer 10

Two or more polypeptide chains in tertiary form combine to form complexes joined by bonds.

Question 11

List 7 functions of proteins in living organisms.

Answer 11

• Muscles
• Haemoglobin
• Enzymes
• Receptors
• Protein carriers
• Antigens/ antibodies
• Hormones