ExtraInfoOnaa

Question 1

At what ph7 does a zwitterion ion form

Answer 1

7

Question 2

What is a zwitterion

Answer 2

Amino group is protonated NH3+

Carboxyl group is deprotomated COO-

Question 3

What is point of inflection.

Answer 3

pH = pKa

Question 4

On titration curve, what region is buffering region

Answer 4

Extending 1pH unit either side of the pKa

Question 5

Why is the pKa for glycines functional groups lower than when they are in simple form

Answer 5

Carboxyl group - Repulsion from departing Ion and Nh3+ lowers pKa + so does oppositely charged groups by stabilising zwitterion
Amino group - electronegative oxygen atoms in carboxyl group pulls electrons away from the amino group which lowers pKa

Question 6

Describe relation between pH and pKa in terms of proton

Answer 6

pH>pKa then proton is off

pH

Question 7

What is isoelectric point

Answer 7

Overall net charge of 0

Question 8

Positive is what

Answer 8

Anode

Question 9

Why is histidine found in the intracellular and extracellular fluids of most animals and bacteria

Answer 9

Because it has an r group providing significant buffering power near neutrality

Question 10

As pH increases above the isoelectric point what happens to the charge

Answer 10

Becomes negative

Question 11

Amino acids are ionised in what solution

Answer 11

Aq