Amino Acids & Proteins

Question 1

Amino acid structure

Answer 1

• amino group; NH2
• carboxyl group; COOH
• side-chain; R- what differs in AAs

Question 2

Acidic vs Basic AAs

Answer 2

Acidic; has a negative charge on the side chain
Basic; has a positive charge on the side chain

Question 3

Proteinogenic AAs

Answer 3

are the building blocks of proteins

Question 4

Non-proteinogenic AAs

Answer 4

have other biological functions beyond making proteins
eg. GABA; neurotransmitter

Question 5

Essential AAs

Answer 5

Cannot be synthesised by the body; needed to be obtained in the diet
eg. His, Leu, Met, Val

Question 6

Non-essential AAs

Answer 6

can be synthesised by the body
eg. Ala, Arg, Asp, Cys

Question 7

Levels of protein structure

Answer 7

• Primary; polypeptide chain sequence, order of AAs
• Secondary; folding due to H bonds- alpha helix or beta-pleated sheet
• Tertiary; further bonding and folding to 3d structure
  -Quaternary; addition of subunits or other elements