Biochem week 2

Question 1

histidine

Answer 1

protonated state of histidine has a positive charge, deprotonated state has a neutral charge

Question 2

glucagon

Answer 2

hormone that regulates glycolysis

Question 3

beta turn (secondary protein structure)

Answer 3

H-bonds between carbonyl-O of first residue and the amide-H of the fourth residue

Question 4

Thermodynamics of protein folding

Answer 4

conformational entropy is large

entropy of protein decreases

free energy of protein decreases

native structure has the lowest free energy (delta G)

overall entropy of H20 increases

Question 5

Amyloidoses

Answer 5

while a protein is folding, sometimes multiple proteins that are folding, their intermediates (molten globular state) can interact with each other and form an amyloid structure

These self associated proteins aggregate -> cause diseases

Question 6

cofactors

Answer 6

anything that will bind to a protein and affect protein structure

Question 7

prosthetic groups

Answer 7

cofactors that bind irreversibly to proteins

Question 8

substrate

Answer 8

cofactors that bind reversibly to proteins

Question 9

Beer lambert law

Answer 9

Abs=ACL

A= extinction coefficient
C= concentration
L= length of light path

Question 10

s-adenosyl methionine

Answer 10

methyl group donor for most biological methylation

Question 11

Inorganic elements as cofactors

Answer 11

serve to maintain active conformations and as electron carrier

Question 12

coenzyme A

Answer 12

carrier of acyl groups

business end is a sulfhydryl group which forms a thioester bond with organic acids

used for biosynthetic rxns (trigylcerides and fatty acid containing lipids)

Question 13

Why do lipids associate in water?

Answer 13

As the lipids aggregate in water, there is an increase in disorder of water molecules therefore the entropy increases and the delta G decreases. The overall system is favorable

deltaG = deltaH - TdeltaS