Nitrogen Metabolism

Question 1

First phase of amino acid catabolism

Answer 1

Deamination

Question 2

Steps in Deamination

Answer 2

1. Transamination

2. Oxidative deamination

Question 3

Enzyme used in transamination

Answer 3

Amino transferase

Question 4

(3) Amino acids that don’t undergo transamination

Answer 4

Lysine
Threonine
Proline

Question 5

Coenzyme in transamination

Answer 5

Pyridoxal phosphate (B6)

Question 6

Enzyme used in oxidative deamination

Answer 6

Glutamate dehydrogenase

Question 7

Enzyme that release ammonia from glutamine

Answer 7

Glutaminase

Question 8

Where does urea cycle occurs?

Answer 8

Liver cytosol and mitochondria

Question 9

(3) substrates of Urea cycle

Answer 9

NH3
Aspartate
CO2

Question 10

Rate limiting step and enzyme in Urea Cycle.

Answer 10

NH3 → Carbamoyl phosphate

Carbamoyl phosphate synthetase I

Question 11

What are the two enzymes used in mitcochondrial reactions in Urea cycle?

Answer 11

1. CPS I

2. Ornithine transcarbomylase

Question 12

2 Purely ketogenic AA

Answer 12

Lysine

Leucine

Question 13

4 Glucogenic and Ketogenic AA

Answer 13

Trypthophan
Phenylalanine
Isoleucine
Tyrosine

(Try Philippine Islands, Ty)

Question 14

Described with musty body oder.

Dx and enzyme deficient

Answer 14

PKU

Phenylalanine hydroxylase

Question 15

Described with ochronosis, osler’s sign.

Dx and enzyme deficient

Answer 15

Alkaptonuria

Homogentisate oxidase

Question 16

Described with stroke in the young, ectopia lentis, mental retardation. High plasma methionine

Dx and enzyme deficient

Answer 16

Homocystinuria

Cystathionine B-Synthase

Question 17

Described with formation of kidney stones and staghorn calculi

Dx and 4 amino acids involved

Answer 17

Cystinuria

Cysteine, Ornithine, Lysine, Arginine
COLA

Question 18

Enzyme deficient in Maple syrup urine disease

Answer 18

A-ketoacid dehydrogenase

Question 19

4 steps in Heme synthesis

Answer 19

1. Formation of delta-Aminolevulinic acid
2. Formation of porphobilinogen
3. Formation of uroporphyrinogen
4. Formation of heme

Question 20

Rate limiting step and enzyme of Heme synthesis

Answer 20

Formation of delta-Aminolevulinic acid

ALA synthase

Question 21

Step inhibited by heavy metals (Lead) in Heme synthesis.

Answer 21

Formation of porphobilinogen and Formation of Heme

Question 22

Enzyme used in formation of bilirubin diglucoronide

Answer 22

Bilirubin glucuronyl-transferase

Question 23

Colorless bile

Answer 23

Urobilinogen

Question 24

Yellow bile

Answer 24

Urobilin

Question 25

Red orange bile

Answer 25

Bilirubin

Question 26

Green bile

Answer 26

Biliverdin

Question 27

(2) enzymes inactivated by Lead at heme synthesis

Answer 27

ALA synthethase and Ferrochelatase

Question 28

Used to measure bilirubin in serum

Answer 28

Van den Bergh Reaction (-) methanol = direct bilirubin (+) methanol = total bilirubin

Question 29

Gilber Syndrome | Direct or Indirect Hyperbilirubinemia

Answer 29

Indirect Hyperbilirubinemia

Question 30

Rotor Syndrome | Direct or Indirect Hyperbilirubinemia

Answer 30

Direct Hyperbilirubinemia

Question 31

Toxic Hyperbilirubinemia | Direct or Indirect Hyperbilirubinemia

Answer 31

Indirect Hyperbilirubinemia

Question 32

Hemolytic Anemias | Direct or Indirect Hyperbilirubinemia

Answer 32

Indirect Hyperbilirubinemia

Question 33

Crigler-Najjar Syndrome I | Direct or Indirect Hyperbilirubinemia

Answer 33

Indirect Hyperbilirubinemia

Question 34

Crigler-Najjar Syndrome II | Direct or Indirect Hyperbilirubinemia

Answer 34

Indirect Hyperbilirubinemia

Question 35

Dubin Johnson | Direct or Indirect Hyperbilirubinemia

Answer 35

Direct Hyperbilirubinemia

Question 36

Principal site of metabolism of branched chain AA

Answer 36

Skeletal muscle

Question 37

Glycogenesis | Active during Absorptive State or Post-Absorptive State

Answer 37

Absorptive

Question 38

Glycogenolysis | Active during Absorptive State or Post-Absorptive State

Answer 38

Post Absorptive

Question 39

Protein synthesis | Active during Absorptive State or Post-Absorptive State

Answer 39

Absorptive

Question 40

TAG synthesis | Active during Absorptive State or Post-Absorptive State

Answer 40

Absorptive

Question 41

Pentose Phosphate Pathway | Active during Absorptive State or Post-Absorptive State

Answer 41

Absorptive

Question 42

VLDL synthesis | Active during Absorptive State or Post-Absorptive State

Answer 42

Absorptive

Question 43

Gluconeogenesis | Active during Absorptive State or Post-Absorptive State

Answer 43

Post Absorptive

Question 44

Decrease Insulin:Glucagon Ratio | Active during Absorptive State or Post-Absorptive State

Answer 44

Post Absorptive

Question 45

Increase Insulin: Glucagon Ratio | Active during Absorptive State or Post-Absorptive State

Answer 45

Absorptive

Question 46

Ketogenesis | Active during Absorptive State or Post-Absorptive State

Answer 46

Post Absorptive

Question 47

Ketolysis | Active during Absorptive State or Post-Absorptive State

Answer 47

None

Question 48

Activates Carbamoyl Phosphate Synthase I

Answer 48

N-Acetyl Glutamate

Question 49

Enzyme deficient in Hyperammonemia type I

Answer 49

Carbamoyl Phosphate Synthase

Question 50

Enzyme deficient in Hyperammonemia type II

Answer 50

Ornithine transcarbamylase

Question 51

Enzyme deficient in Citrullinemia

Answer 51

Arginosuccinate synthetase

Question 52

Enzyme deficient in Argininosuccinate aciduria

Answer 52

Arginosuccinase

Question 53

Enzyme deficient in Arginemia

Answer 53

Arginase

Question 54

Most common deficiency involving urea cycle enzymes

Answer 54

Ornithine transcarbamylase deficiency

Question 55

Triad of Alkaptonuria

Answer 55

Ochronosis Black Urine Arthritis

Question 56

Pellagra skin rash, ataxia, neurodegenerative changes with defect in intestinal and renal transport of Tryptophan

Answer 56

Hartnup disease

Question 57

Also called Gammaglutamylcysteinylglycine

Answer 57

Gluthathione