Nitrogen Metab and Integration of Metabolism Flashcards Preview

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Flashcards in Nitrogen Metab and Integration of Metabolism Deck (64):
1

How much is the protein turnover per day

300-400g

2

Catabolism of amino acids turns them into this final product

A- keto acid

3

The first phase of amino acid catabolism involves transferring their amino group to a-ketoglutarate forming this amino acid

Glutamate

4

Enzyme in the transamination step of the 1st phase of amino acid catabolism

Aminotransferase

5

Coenzyme of aminotransferase in Transamination

B6 pyridoxal phosphate

6

In the 2nd step of the 1st phase of AA catabolism, glutamate is oxidatively deaminated to release free ammonia in which organs

Liver and kidney

7

What is the enzyme involved in the oxidative deamination step of AA catabolism?

Glutamate dehydrogenase

8

Transport of ammonia to peripheral tissues is through this amino acid

Glutamine through glutamine synthase

9

Glutamine can also be transported in the blood and deaminated to release ammonia in these organs

Liver and kidney through glutaminase

10

Exceptions to transamination of amino acids to glutamate

Lysine
Threonine
Proline
Hydroxyproline

11

Transport of ammonia in the muscle is possible when pyruvate is transaminated to what amino acid

Alanine

12

Excretion of excess nitrogen in telostean fish which excrete highly toxic ammonia

Ammonotelic

13

Excess nitrogen excretion in birds which secrete uric acid as semisolid Guano

Uricotelic

14

Excess nitrogen excretion in land animals who excrete it as urea

Ureotelic

15

In what organ does the urea cycle occur?

Liver only

16

Where in the cell does urea cycle occur?

Both mitochondria and cytosol

17

Substrates of Urea cycle

NH3
Aspartate
CO2

18

What is the rate limiting step of urea cycle?

NH3 + CO2 to carbamoyl phosphate through carbamoyl phosphate synthetase 1

19

Allosteric activator of carbamoyl phosphate synthetase 1

N- acetylglutamate

20

Most common enzyme deficiency in Urea cycle

Ornithine transcarbamoylase

21

Link of urea cycle to Krebs cycle

Fumarate

22

1 mol of urea needs how many ATP?

3 mol of ATP
but 4 high energy bonds (AMP)

23

Urea can be excreted through

Urine
Intestines where bacteria converts it to CO2 and NH3

24

This disease has a direct neurotoxic effect on the CNS

Tremors, slurring of speech, vomiting, BOV, cerebral edema

Hyperammonemia

NH3--a ketoglutarate--glutamate (excitatory)

25

Most severe form of hereditary hyperammonemia

Carbamoyl phosphate synthetase 1 deficiency

26

Treatment for hereditary hyperammonemia that binds to glutamine and excreted as phenylglutamine

Phenylbutyrate

27

Purely ketogenic amino acids (may be converted to acetyl CoA of acetoacetyl CoA)

Ketong-genic

Lysine
Leucine

28

Amino acids that are both ketogenic and glucogenic

Try Philippine Islands TY

Tryptophan
Phenylalanine
Isoleucine
Tyrosine

29

NO, creatine and polyamines is a derivative of which amino acid

Argggh NO Creating here

Arginine

30

Coenzyme A, taurine and glutathione is a derivative of which amino acid

TAU pa RINE ba si Christeine, ang cO-A ng puti kaka-Gluta

Taurine
Coenzyme A
Glutathione

31

Products of this amino acid include heme, purines, creatine, glutathione

Glycine

32

Thymine, purine and sphingosine comes from this amino acid

Serine

33

Cofactor of phenylalanine hydroxylase that may be deficient in phenylketonuria

Tetrahydrobiopterin

34

This phenylketone gives the characteristic odor of urine in phenylketonuria

Phenylacetate

35

Congenital deficiency in homogentisate oxidase that leads to homogentisic acid accumulation

Urine turns black upon standing, arthralgia, dark connective tissue

Alkaptonuria

36

Homocystinuria happens due to defect in the degradation of this amino acid

Methionine

37

Ectopis lentis (downward)
Osteoporosis
MR
thrombi formation, MI, stroke in children and adults

Homocystinuria

38

Treatment for homocystinuria

Vitamin B6 B12 and folate

39

Cystinuria is an inherited defect of renal tubular amino acid transporter for which amino acids in the PCT of the kidneys

COLA
Cystine
Ornithine
Lysine
Arginine

40

Cystinuria can precipitate formation of ______ in the kidney

Staghorn calculi

41

This drug is used to treat cystinuria to alkalinize the urine

Acetazolamide

42

Methylmalonyl CoA mutase deficiency can cause a defect in the conversion of methylmalonyl to succinyl CoA

Stroke, seizures, enceph at 1 mo to 1 yr old
And involves metabolism of these amino acids

TIM V
Threonine
Isoleucine
Methionine
Valine

43

Maple syrup urine disease is due to blocked degradation of branched chain amino acids because of deficiency in this enzyme

A-ketoacid dehydrogenase

44

These are cyclic compounds formed by the linkage of 4 pyrrole rings through methyne bridges

Porphyrins

45

What is the rate limiting step of heme synthesis

Formation of d-ALA from glycine and succinyl CoA through ALA synthase

46

Cofactor of ALA synthase in the rate limiting step of heme synthesis

Pyridoxine

47

Formation of porphobilinogen is inhibited by

Heavy metal ions that replace zinc

48

What enzyme catalyzes the formation of heme from protoporphyrin IX?

Ferrochelatase

49

In heme degradation, bilirubin is conjugated to 2 molecules of glucoronic acid for excretion. This enzyme is deficient in Crigler Najjar and Gilbert syndrome

Bilirubin glucuronyltransferase

50

Bilirubin in stool is called

Stercobilin

51

Bilirubin in urine is called

Urobilin

52

Bilirubin in the intestines is called

Uronilinogen

53

Enzymes in heme synthesis inhibited by lead

ALA dehyratase
Ferrochelatase

54

Most common form of porphyria

Porphyria cutanea tarda

55

Porphyria that occurs before the formation of ring leads to accumulation of ALA and PBG and lead to what symptom

Neuropsychiatric

56

Accumulation of porphyrinogens in the skin can undergo spontaneous oxidation to porphyrins and cause this symptom

Photosensitivity

57

Direct or Indirect hyperbilirubinemia?

Dubin- Johnson
Rotor

Direct

58

Crigler Najjar and Gilbert syndrome can cause what type of hyperbiliruninemia

Indirect

59

Epinephrine, cortisol and GH has similar effects to what hormone

Glucagon

60

Principal site of metabolism of branched chain amino acids

Skeletal muscle

61

Energy store used for sprinting

Creatine phosphate

62

Energy store used in marathons

Glycogen and fatty acids

63

In fasting state, glycogen is used as fuel for how many hours into the fasting?

18-24 hours

64

Peak of Ketone bodies being used as fuel in starvation

10 days