Amino Acid Metabolism

Question 1

General rule of amino acid catabolism

Answer 1

Removal of alpha amino group, and converting to alpha keto acid into a metabolic intermediate.

Question 2

Removal of amino group from alanine and transfer it to alpha keto glutarate generates pyruvate (alpha keto acid of alanine) and glutamate ( made when alpha keto glutamate accepts an amino group. This is an example of

Answer 2

Transamination

Question 3

Explain conversion to intermediate , followed by transamination

Answer 3

Removing the amino group from asparagine to make aspartate (via-aspariginase)

Now aspartate amino transferase will take amino group and add it to alpha keto glutarate to make glutamate and OAA ( deaminated aspartate)

Question 4

Conversion to glutamate

Answer 4

Remove the amino group from glutamine to make glutamate.

Question 5

Oxidative deamination of glutamate.

Answer 5

Deaminination of glutamate to make alpha keto glutarate. This regenerates the acceptor.

Question 6

General overview of channeling an Amino group into the urea cycle

Answer 6

Donate the amino group to AKG to make glutamate. (Alpha amino transferases)

Glutamate donates the amino group to NAD (P) to make NADPH and regenerates the alpha keto glutarate.

Now Ammonia can be made into urea.

Question 7

Where do the 2 nitrogens come from on urea?

Answer 7

1. From free ammonia

2. Another from aspartate

Question 8

Alanine undergoes what reaction to get ammonia from muscle to liver ?

Answer 8

Alanine amino transferase

Question 9

Glutamine …

Answer 9

has two nitrogens , one from alpha amino group and one on the side chain. It can go to the kidney and be metabolized for the synth of glucose and to rid of ammonia.

Glutamine can go to the liver and the kidney

Question 10

Cortisol and cytokine action of alpha Amino transferases

Answer 10

Activates

Question 11

regulation of glutamate hydrogenase

Answer 11

ADP (activates) - fasting increases activity of the ureas cycle.

ATP (inhibits) – fed state and insulin inhibits.

Question 12

How N-acetylglutamate becomes present to activate

Answer 12

Fasting increases glutamate and Ace-CoA. Now the substrates are available. Insulin inhibits N-acetylglutamate. So in a fasted state, its like taking the foot off the break.

Question 13

Hereditary HYperammonemia

Answer 13

defects in ornithine transcarbamoylase

second step in ureas cycle.

Question 14

PKU defect

Answer 14

Phenylalanine hydroxyls

Leads to accumulation of

Phenyllactate
Phenylacetate
Phenylpyruvate