06 Proteins - From function to structure and back

Question 1

Roles of protein

Answer 1

• catalyze reactions (enzymes)
• involved in nucleic acid interactions
• act as receptors
• provide structure to cells and tissues
• antibodies

Question 2

What is the type of amino acid human proteins use?

Answer 2

L-alpha amino acids

Question 3

What is a zwitterion?

Answer 3

a molecule with equal number of +ve and -ve charged functional groups

Question 4

20+1 amino acids

Answer 4

Aspartic acid (Asp)
Glutamic acid (Glu)
Arginine (Arg)
Lysine (Lys)
Histidine (His)
Asparagine (Asn)
Glutamine (Gln)
Serine (Ser)
Threonine (Thr)
Tyrosine (Tyr)
Alanine (Ala)
Glycine (Gly)
Valine (Val)
Leucine (Leu)
Isoleucine (Ile)
Proline (Pro)
Phenylalanine (Phe)
Methionine (Met)
Tryptothan (Trp)
Cysteine (Cys)

(Selenocysteine)

Question 5

Name the negatively charged amino acids

Answer 5

Aspartic acid
Glutamic acid

Question 6

Name the positively charged amino acids

Answer 6

Arginine
Lysine
Histidine

Question 7

Secondary structure of protein is due to interactions of what?

Answer 7

atoms in backbone

Question 8

Why is a alpha helix or beta sheet stable?

Answer 8

H-bonds

Question 9

How many amino acids per 360˚ turn in alpha helix?

Answer 9

3.6

Question 10

Handedness of alpha helix?

Answer 10

Right-handed helix

Question 11

Tertiary structure of protein is due to interactions between?

Answer 11

amino acid side chains