biochem pH and pKa

Question 1

pka

Answer 1

the pH at which 50% of mol. deprotonated

= tendency to keep protons

LOW pka = low acceptance of protons, good donor, good acid

Question 2

pH > pka

Answer 2

majority deprotonated, not many hydrogens in solution

Question 3

pH < pka

Answer 3

majority protonated, many H’s in solution?

Question 4

pH = pKa

Answer 4

[protonated] = [deprotonated] ?

Question 5

pH = (+/-1 of pKa)

Answer 5

good buffer

Question 6

pI of acidic aa

Answer 6

acidic aa’s

Question 7

pI of basic aa

Answer 7

basic aa’s:

Question 8

pKa of cysteine side chain

Answer 8

6.5