Proteins-amino acids as buffers

Question 1

What’s a buffer

Answer 1

a solution which resists changes in pH when acid/alkali is added to it.

Question 2

Can amino acids act as a buffers

Answer 2

Yes, When dissolved in water, the amine group and carboxyl group are ionised.This means that the amine group can accept an H+ ion to change from NH2+ to NH3+. The carboxyl group can give up an H+ ion to change from COOH to COO-

Question 3

Draw the equation of an carboxyl group getting ionised

Question 4

Draw the equation of an amino group getting ionised

Question 5

What’s an acid

Answer 5

a substance that produces H ions, H+(aq), when dissolved in water

Question 6

What’s an alkali/base

Answer 6

accepts H ions(H+)and when added to water, it soaks up the H ions formed by the dissociation of water so that the balance shifts in favor of the hydroxyl ion(OH-)concentration.

Question 7

How does an amino acid act as a buffer

Answer 7

By accepting H+ ions ,
-At low ph (where there are lots of H+ ions in solution), the amino group (base)will accept H+ ions.
-At high pH (where there are fewer H+ ions in solution), the carboxyl group(acid)will release H+ ions.

Question 8

How does the carboxyl group act as an acid

Answer 8

It produces H ions H+(aq), when dissolved in water

Question 9

What does amphoteric mean

Answer 9

able to react both as a base and as an acid.

Question 10

How does amphoteric nature of amino acids affect protein chains

Answer 10

By accepting and releasing H+ ions amino acids can help regulate changes in Ph = a buffer

Question 11

Are amino acids amphoteric

Answer 11

Yes