Amino Acid Met 1

Question 1

What are the two most important places where amino acid transporters are expressed?

Answer 1

Lumen of digestive tract and kidney

Question 2

How are most AA transported into small intestine cells?

Answer 2

As peptides. Then into blood mostly as AA

Question 3

Hartnup disease cause and symptoms?

Answer 3

Defect in absorption of neutral AA. Neutral AA in urine, and pellagra( due to tryptophan deficiency)

Question 4

Cystinuria symptoms and cause?

Answer 4

Defect in transport of basic AA. Excess cystine or ornithine. Kidney stones

Question 5

Marasmus symptoms and cause?

Answer 5

Starvation. No edema, no fatty liver, cortisol up. Loss of mass

Question 6

Kwashiorkor symptoms and cause?

Answer 6

Not enough protein in diet. Edema, fatty liver, low serum albumin.

Question 7

Where does urea cycle take place?

Answer 7

Liver

Question 8

Glucogenic AA produce what?

Answer 8

Pyruvate or OAA

Question 9

Ketogenic AA produce what?

Answer 9

Acetyl CoA or acetacetyl CoA

Question 10

What are the three steps of nitrogen metabolism?

Answer 10

Transamination, deamination, ammonia into urea

Question 11

Transamination process?

Answer 11

Alpha-ketoglutarate accepts N, becoming glutamate.

Question 12

Aspartate transaminase uses what pair?

Answer 12

Aspartate and OAA

Question 13

Alanine transaminase uses what pair?

Answer 13

Alanine and pyruvate

Question 14

Deamination done by what?

Answer 14

Glutamate dehydrogenase. Occurs in matrix, uses NAD or NADP and is reversible.

Question 15

What happens in brain in hyperammonemia?

Answer 15

Brain uses A-ketoglutarate to produce glutamate. Results in encephalopathy

Question 16

In skeletal muscle, glutamate can turn pyruvate to what?

Answer 16

Alanine, to transport ammonia to liver

Question 17

Glutamine has how many ammonia’s?

Answer 17

2. First done by glutaminase, second by glutamate dehydrogenase

Question 18

How many ATP does urea need to form?

Answer 18

4

Question 19

First step urea cycle enzyme? Substrates and product?

Answer 19

CPS1. NH4 and bicarb. Carbamoyl phosphate. Rate limiting, needs N Acetyl glutamate and 2 ATP.

Question 20

2nd step urea cycle enzyme? Needs and makes?

Answer 20

OTC produces citrulline from carbamoyl phosphate and ornithine. In mitochondria

Question 21

Step 3 urea enzyme and product?

Answer 21

Argininosuccinate synthase. Makes argininosuccinate from citrulline and aspartate. Needs ATP

Question 22

Step 4 urea enzyme and product?

Answer 22

Argininosuccinate lyase. Makes fumarate and arginine

Question 23

Step 5 urea enzyme and product?

Answer 23

Arginase. Urea and ornithine

Question 24

Steps one through 5 urea cycle deficient symptoms?

Answer 24

1-alanine up
2-orotic acid up
3-citrulline up
4-arginino succinate up
5- arginine up