Nitrogen Balance

Question 1

which AA can be made by the body but is still consdred to be essential?

Answer 1

Arginine

Question 2

marker of protein malnutrition

Answer 2

albumin

Question 3

the primary amino acid transported from the muscle to the liver for gluconeogenesis

Answer 3

alanine

Question 4

How do we convert alanine to pyruvate

Answer 4

you react it with alpha KG. The alpha KG becomes glutamine

Question 5

one you have made glutamine, by transferrring an amino group from alanine to alpha KG, what do you do with the nitrogen?

Answer 5

You either use glutamine dehydrogenase to produce ammonia that goes to the urea cycle. Or you react the glutamine with OAA. OAA will take the nitrogen from glutamine and become aspartic acid. Aspartic acid can enter the urea cycle

Question 6

why is nitrogen important for the kidney?

Answer 6

the ammonia is used to saok up protons during acidosis situations

Question 7

what is the cofactor for all ALT and AST reactions

Answer 7

PLP/ pyridoxine B6

Question 8

what does glutamate dehydrogenase do?

Answer 8

it breaks glutamic acid into ammonia and alpha KG, the ammonia will now enter the urea cycle

Question 9

what enzyme takes alanine t pyruvate

Answer 9

ALT

Question 10

what enzyme takes OAA to aspartic Acid?

Answer 10

AST

Question 11

Ammonia enters the urea cycle via

Answer 11

free ammonia and aspartic acid

Question 12

what keto acid forms aspartic acid?

Answer 12

OAA

Question 13

in ALL what amino acid becomes essential?

Answer 13

asparagine, so treat with asparaginase

Question 14

regulation of urea cyce?

Answer 14

CPS1

Question 15

CPS1 is activated by what?

Answer 15

N acetyl glutamic acid

Question 16

where do you get n acetyl glutamic acid?

Answer 16

Glutamic acid and acetyl CoA combine via n-acetyl glutamate synthase to make n acetyl glutamic acid

Question 17

what activates the enzyme that makes n-acetly glutamic acid?

Answer 17

n-acetyl glutamic synthase, is activated by arginine ,

Question 18

in which disease do you have a high level of ornithine?

Answer 18

OTCase deficiency: since carbamoyl phosphate builds up and enters pyrimidine synthesis. Orotic acid is part of the pathway

Question 19

which disease is X-linked?

Answer 19

OTCase deficiency

Question 20

Three ways of treating urea cycle disorders

Answer 20

benzoid acid: binds to glycine and is excrete in the urine –> excretion of nitrogen
phenylacetate: reacts w glutamine which will be excreted and excrete 2 ammonia
Keto acids: convert glutamic acid to alpha KG,. Glutamic acid donates ammonia to the urea cycle, so this decreases the ammonia entering the ammonia cycle

Question 21

how do you treat citrullemia?

Answer 21

With arginine! You need to have ornithine to react with the carbamoyl phopshate and form citrulline. Since citrulline can be excreted in the urine, you want to at least make it to the later steps of the urea cycle