protien structures

Question 1

primary

Answer 1

Sequence of amino acids in a polypeptide chain, joined by peptide bonds

Question 2

2ndry

Answer 2

● Folding (repeating patterns) of polypeptide chain eg.
alpha helix / beta pleated sheets
● Due to hydrogen bonding between amino acids
● Between NH (group of one amino acid) and C=O (group)

Question 3

teriarty

Answer 3

3D folding of polypeptide chain
● Due to interactions between amino acid R groups
(dependent on sequence of amino acids)
● Forming hydrogen bonds, ionic bonds and disulfide bridges

Question 4

quartnerary

Answer 4

● More than one polypeptide chain
● Formed by interactions between polypeptides
(hydrogen bonds, ionic bonds, disulfide bridges)

Question 5

Describe how amino acids join together

Answer 5

● Condensation reaction
● Removing a water molecule
● Between carboxyl / COOH group of one
and amine / NH2 group of another
● Forming a peptide bond

Question 6

comp inhibitor

Answer 6

● As concentration of competitive inhibitor increases, rate of
reaction decreases
○ Similar shape to substrate
○ Competes for / binds to / blocks active site
○ So substrates can’t bind
○ So fewer enzyme-substrate complexes form
● Increasing substrate concentration reduces effect of inhibitors
(dependent on relative concentrations of substrate and inhibitor)

Question 7

non comp inhibitor

Answer 7

● As concentration of non-competitive inhibitor increases, rate of
reaction decreases
○ Binds to site other than the active site (allosteric site)
○ Changes enzyme tertiary structure / active site shape
○ So active site no longer complementary to substrate
○ So substrates can’t bind
○ So fewer enzyme-substrate complexes form
● Increasing substrate concentration has no effect on rate of
reaction as change to active site is permanent