T2L3 Protein Structure

Question 1

What are the five main parts of an amino acid?

Answer 1

Central carbon atom
Hydrogen
Amine NH2 group
Carboxyl COOH group
R residual group - unique to each amino acid

Question 2

Describe what the primary structure of a proteinis

Answer 2

The sequence of amino acids joined together by peptide bonds resulting in a polypeptide chain

Question 3

Describe what the secondary structure of a protein is

Answer 3

When hydrogen bonds form between amino acids between nearby amino acids ( to normally form either an alpha helix or a beta pleated sheet

Question 4

Describe what the tertiary structure of a protein is
(name 4 bonds)

Answer 4

When more bonds form between different R groups to form the specific 3D structure of the protein.

These bonds are:
- ionic
-disulfide
- hydrophobic interactions
- hydrogen bonds

Question 5

Describe what a quaternary structure is

Name a protein that has a quaternary structure

Answer 5

Formed when a protein is made from more than one polypeptide chain.

Haemoglobin

Question 6

What are the 2 different types of protein

Answer 6

Fibrous and Globular

Question 7

Name 4 characteristics of a globular protein

Answer 7

• The shape is spherical
• This is what type of protein enzymes are
• Soluble
• Have hydrophilic side chains

Question 8

Name 2 examples of globular proteins

Answer 8

• Haemoglobin
• Insulin

Question 9

Name 4 characteristics of a fibrous protein

Answer 9

• Long (polypeptide) chains
• Cross-linked for strength
• Structural proteins
• Tend to be less sensitive to changes in temperature and pH than globular

Question 10

Name 2 examples of fibrous proteins

Answer 10

Keratin
Collagen