General enzyme properties + effect of pH

Question 1

What do biological catalysts do?

Answer 1

-enhance rate of chemical reactions
-don’t alter equilibrium of reactions
-reduce energy barrier for forward + reverse reactions

Question 2

What is the dissociation constant?

Answer 2

Ka = (H+ conc. x A- conc.) / conc. HA

Question 3

How do you calculate pKa?

Answer 3

pKa = -log Ka

Question 4

On a graph, what does the point pI represent?

Answer 4

Where all +ive and -ive charges are balanced

Question 5

What is the protonation state of the side chain of residue(s) usually responsible for?

Answer 5

The pH dependent reaction profile

Question 6

What can influence the pKa of a side chain?

Answer 6

The local environment

Question 7

What is the ratio of deprotonated to protonated?

Answer 7

[A]/[HA]

Question 8

What does the protonation state depend on?

Answer 8

The pKa of the functional group

Question 9

How do you calculate pH using the Henderson-Hasselbalch equation?

Answer 9

pH = pKa + log([A-]/[HA])