Levels Of Protein Structure

Question 1

What are the 4 structures?

Answer 1

-primary
-secondary
-tertiary
-quaternary

Question 2

What is the primary structure?

Answer 2

-1 amino acid sequence bonded by peptide bonds

Question 3

What is secondary structure?

Answer 3

-form when weak -N + -O interact with weak +H = H bonds
-form alpha helix or beta pleated sheet

Question 4

How are alpha helixes formed?

Answer 4

-H bonds form between every 4th peptide bond

Question 5

How is a beta pleated sheet formed?

Answer 5

-protein folds so 2 parts of the chain are parallel to each other
-H bonds form between these

Question 6

Examples of secondary structure fibrous proteins

Answer 6

-collagen
-keratin

Question 7

What is tertiary structure?

Answer 7

-overall 3D shape of a polypeptide chain
-first chain folds into regions of secondary structure
-continue folding
-structure is critical for functions

Question 8

What is quaternary structure?

Answer 8

-only applies to proteins with at least 2 subunits

Question 9

An example of quaternary structure?

Answer 9

-haemoglobin - 4 polypeptide chains
-contains prosthetic group haem
-binds to O
-known as a conjugated protein

Question 10

What are prosthetic groups?

Answer 10

-proteins containing other non-protein groups to help the protein carry out its role