Amino Acid Metabolism

Question 1

Which AA can be phosphorylated?

Answer 1

Serine, threonine, tyrosine

Question 2

Which AA is borderline borderline wrt polarity: sometimes
grouped with neutral polar aa’s?

Answer 2

Cysteine

Question 3

Which AA cannot rotate freely around α-C, so
not found in protein structures that require
rotation (ex α-helix)

Answer 3

Proline

Question 4

Which AA in the thiol group can form disulfide bonds? Which important proteins are these bonds a part of?

Answer 4

Cysteine / keratin, insulin, glutathione (antioxidant)

Question 5

Which AA help bind metals? Why?

Answer 5

cysteine and methionine, because they contain S.

Question 6

Which type of bonding can both the amide group of the hydroxyl group participate in?

Answer 6

Hydrogen bonding

Question 7

In AAs, the nonpolar side chains are (hydrophobic / hydrophilic)?

Answer 7

hydrophobic

Question 8

In AAs, the polar, acidic and basic side chains are (hydrophobic / hydrophilic)?

Answer 8

hydrophilic

Question 9

Every amino acid contains at least 1 ________?

Answer 9

Nitrogen

Question 10

What are the 3 different ways nitrogen can be incorporated into an amino acid?

Answer 10

transamination (indirect), transamidation (indirect) , and direct incorporation

Question 11

What does transamination involve?

Answer 11

Transferring an amino group from an amino acid to an alpha ketoacid

Question 12

3 amino acid and alpha ketoacid pairs to memorize are:

Answer 12

Alanine and pyruvate
Glutamate and alpha ketoglutarate
Aspartate and oxaloacetate

Question 13

Transaminations require a _______________

Answer 13

coenzyme (PLP)

Question 14

What does transamidation involve?

Answer 14

Transferring an amido group from an amino acid to an alpha ketoacid

Question 15

What happens in direct incorporation?

Answer 15

The addition of N directly from ammonia and can require a B3 coenzyme

Question 16

Which amino acids are in the Glutamate family?

Answer 16

glutamine, proline, arginine

Question 17

Where is glutamine synthetase highly concentrated?

Answer 17

In the brain

Question 18

Which amino acids are in the aspartate family?

Answer 18

Asparagine, lysine, threonine, methionine, isoleucine

Question 19

Which amino acids are in the pyruvate family?

Answer 19

Alanine, valine, leucine

Question 20

Which AAs are in the aromatic family?

Answer 20

tryptophan, phenylalanine, tyrosine

Question 21

Which amino acids are in the serine family?

Answer 21

serine, cystein and glycine

Question 22

To be used as an enzyme, folate is first converted into _____________?

Answer 22

tetrahydrofolate

Question 23

____ in an important electron carrier in the ETC

Answer 23

CoQ

Question 24

Which AAs are in the histidine family?

Answer 24

histidine

Question 25

True or false. catabolism is the opposite pathway to anabolism

Answer 25

False

Question 26

Catabolism of AA requires ___________ to produce a carbon skeleton and an ammonium ion

Answer 26

deamination

Question 27

After deamination, what happens to the NH4+?

Answer 27

It is converted to urea in the liver and excreted in the urine by the kidneys

Question 28

What happens to the AA carbon skeletons?

Answer 28

They feed into ketogenic (to make ketone bodies) and/or gluconeogenic (to make glucose) cycles