PROTEIN METABOLISM I

Question 1

continuous degradation and resynthesis of all cellular proteins

Answer 1

protein turnoever

Question 2

susceptibility of a protein to degradation is expressed as its

Answer 2

HALF LIFE

Question 3

half-lives for liver proteins range from under

Answer 3

30 mins to over 150 minutes

Question 4

proteins with half lives over 100 hours include

ALC

Answer 4

aldolase, lactate dehydrogenase, and cytochromes

Question 5

two major pathways that degrade intracellular proteins of eukaryotic cells

Answer 5

lysosomal degradation
ubuiquitin

Question 6

lysosomes have a selective pathway which is activated only after a prolonged fast, that imports and degrades cytosolic proteins containing the pentapeptide KFER1 (lys-phe-glu-arg-gln) or a closely related sequence

Answer 6

Lysosomal degredation

Question 7

proteins are marked for degradation by covalently linking them to ____________

Answer 7

ubiquitin

Question 8

3 amino acids that are not metabolized in the liver

Answer 8

Valine Leucine Isoleucine

Question 9

Valine Leucine Isoleucine are metabolized in the __________

Answer 9

brain and muscles

Question 10

amino acids that can not be synthesized by the body so they must be provided in the diet

Answer 10

essential or indispensible amino acids

Question 11

amino acids can be synthesized by the body so they need not be provided in the diet

Answer 11

non-essential or dispensible

Question 12

semi-essential amino acid

Answer 12

arginine

Question 13

3 enzymes that occupy central positions in amino acid biosynthesis

G-G-A

Answer 13

glutamate dehydrogenase
glutamine synthetase
aminotransferases

Question 14

3 enzymes that occupy central positions in amino acid biosynthesis

used to synthesize glutamic acids

Answer 14

glutamate dehydrogenase

Question 15

3 enzymes that occupy central positions in amino acid biosynthesis

used to synthesize glutamine

Answer 15

glutamine synthetase

Question 16

3 enzymes that occupy central positions in amino acid biosynthesis

enzymes that are used for transamination
can be used to synthesize many other amino acids

Answer 16

aminotransferases

Question 17

types of amino acid catabolism

Removal
D
O
O

Answer 17

removal of alpha-amino group
decarboxylation
oxygenation
one carbon transfer

Question 18

removal of alpha amino group

amino acid —-> keto acid + NH3

Answer 18

oxidative deamination

Question 19

glu is the only amino acid that

undergous oxidative deamination at an appreciable rate in mammalian tissues

Answer 19

glutamate dehydrogenase

Question 20

the most active amino group acceptor

Answer 20

alpha ketoglutarate

Question 21

remember that in your amino acids are ________ acids

Answer 21

L-Amino Acids

Question 22

abnormal neural development generalized aminoaciduria absence of peroxisomes in a liver biopsy

aminoaciduria is due to deficient amino acid oxidase activity

L amino acid oxidase activity

Answer 22

zellweger cerebrohepatorenal syndrome

Question 23

non-oxidative deamination

requires pyrodoxal phosphate (B6PO4) as cofactor

hydroxy amino acids (serine, threonine, tyrosine, homoserine)

Answer 23

amino acid dehydrases

Question 24

non-oxidative deamination

requires pyrodoxal phosphate (B6PO4) as cofactor

sulfur containing amino acids (cysteine, homocysteine, methionine)

Answer 24

amino acid desulfydrases

Question 25

_________- produces a new keto acid and a new amino acid enzyme: transaminase/aminotransferase

Answer 25

transamination

Question 26

leads to formation of biogenic amines

Answer 26

decarboxylation

Question 27

examples of decarboxylation are S H C

Answer 27

serotonin histamine catecholamines

Question 28

ways of detoxifying ammonia are Reversal G formation U formation A formation

Answer 28

glutamate dehydrogenase glutamine formation urea formation asparagine formation

Question 29

glutamine formation whenever ammonia reaches the brain, the brain combines it with glutamic acid , converting it to glutamine using the enzyme _______

Answer 29

glutamine synthetase

Question 30

major source of ammonia excreted in the urine?

Answer 30

glutamine

Question 31

most nitrogenous excretory product serves as the disposal form of ammonia, toxic particularly to the brain and CNS

Answer 31

urea

Question 32

how many ammonias are detoxified in the urea cycle

Answer 32

2 amonnias

Question 33

how many ATPs are priduced in the Urea cycle pathway?

Answer 33

4 ATPs

Question 34

major control points of urea pathway CPS OT A

Answer 34

carbamoyl phosphate synthetase I ornithine transcarbamoylase Arginase

Question 35

HHH syndrome due to the mutation of the ornithine transporter gene (ORNT1) 3 manifestations are

Answer 35

hyperammonemia hyperornithinemia homocitrullinuria

Question 36

in the 4th reaction, Argininosuccinate is cleaved to form fumarate and _______

Answer 36

arginine

Question 37

enzyme deficient in hyperammonemia type 1

Answer 37

carbamoyl phosphate synthetase I

Question 38

enzyme deficient in hyperammonemia type 2

Answer 38

ornithine transcarbamoylase

Question 39

enzyme deficient in citrullinemia

Answer 39

argininosuccinate synthetase

Question 40

enzyme deficient in argininosuccinate aciduria

Answer 40

argininosuccinase

Question 41

enzyme deficient in arginemia

Answer 41

arginase