Endo: Catabolism Of carbon skeleton Of AA

Question 0

AAs that don’t undergo transamination

Answer 0

Proline, Hydroxyproline, Lysine & Threonine “PaHaLaTa”

Question 1

First catabolic reaction of AA catabolism

Answer 1

Removal of a-amino nitrogen by transamination

Question 2

AA are converted into _________ or their precursor so that they can be metabolized to ___ & ___ or used in ______. Accounts for ____ of metabolic energy generated by animals.

Answer 2

CAC intermediates. CO2 & H2O. Gluconeogenesis. 10-15%.

Question 3

Carbon skeletons are degraded into Pyruvate, succinyl coa, oxaloacetate or fumarate and a-ketoglurate and are therefore glucose precursor. “Pa SOFA”

Answer 3

Glucogenic AA

Question 4

Carbon skeletons are broken down to acetyl coA or acetoacetate and can thus be converted to fatty acids or ketone bodies.

Answer 4

Ketogenic AA

Question 5

Only ketogenic AA

Answer 5

Leucine

Question 6

Glucogenic and Ketogenic AA at the same time

Answer 6

Phenylalanine, Lysine, Isoleucine, Tryptophan & Tyrosine “PLITT”

Question 7

AA converted to pyruvate

Answer 7

Cysteine, Threonine, Tryptophan, Alanine, Glycine & Serine “CT TAGS”

Question 8

AA coverted to oxaloacetate

Answer 8

Aspartate & Asparagine “AA”

Question 9

AA converted to a-ketoglutarate

Answer 9

Proline, Histidine, Arginine, Glutamate & Glutamine “Pa HAGG”

Question 10

AA converted to fumarate

Answer 10

Phenylalanine, Aspartate & Tryptophan “PAT”

Question 11

AA converted to succinyl coA

Answer 11

Valine, Isoleucine & Methionine “VIM”

Question 12

AA degraded to acetyl coA or acetoacetate

Answer 12

Phenylalanine, Isoleucine, Leucine, Lysine, Tryptophan, Threonine & Tyrosine “PILL T3”

Question 13

Transamination forms pyruvate which can then be decarboxylated to acetyl CoA

Answer 13

Alanine

Question 14

Splits to CO2 and NH4 and N5, N10 Methylene Tetrahydrofolate

Answer 14

Glycine

Question 15

Transamination of glycine to ______ with Glu or Ala

Answer 15

Glyoxylate

Question 16

Failure to catabolize glyoxylate leads to

Answer 16

Hyperoxaluria

Question 17

Degraded to glycine and N5, N10 methylene tetrahydrofolate

Answer 17

Serine

Question 18

Enzyme used to convert serine to pyruvate

Answer 18

Serine hydratase

Question 19

Converted to cysteine

Answer 19

Cystine

Question 20

Cysteine is catabolized via what pathways

Answer 20

Direct oxidative pathway & Transamination pathway

Question 21

Enzyme used to convert cystine to cysteine

Answer 21

Cystine reductase

Question 22

Cysteine: direct oxidative pathway

Answer 22

Cysteine [cysteine deoxygenase] cysteine sulfinate [transaminase] sulfinyl pyruvate [desulfinase] pyruvate

Question 23

Cysteine: transamination pathway

Answer 23

Cysteine [transaminase] 3 mercaptopyruvate = pyruvate & 3 mercaptolactate

Question 24

Cleaved to acetaldehyde and glycine

Answer 24

Threonine

Question 25

Oxidized to acetate which is then converted to acetyl CoA

Answer 25

Acetaldehyde

Question 26

Pathway of Threonine

Answer 26

Threonine [threonine aldolase] acetaldehyde [aldehyde dehydrogenase] acetate [acetate thiokinase] acetyl CoA

Question 27

Transamination forms oxaloacetate

Answer 27

Aspartate

Question 28

Undergoes hydrolysis to aspartate

Answer 28

Asparagine

Question 29

Aspartate and Asparagine pathway

Answer 29

Asparagine [asparaginase] Aspartate [transaminase] Oxaloacetate

Question 30

Transamination forms a-ketoglutarate

Answer 30

Glutamate

Question 31

Undergoes hydrolysis to glutamate

Answer 31

Glutamine

Question 32

Glutamate and Glutamine Pathway

Answer 32

Glutamine [glutaminase] Glutamate [transaminase] a-Ketoglutarate

Question 33

Oxidized to dehydroproline which then adds water forming ___________. This is then oxidized to _______ and transaminated to _________.

Answer 33

Proline. Glutamate y-semialdehyde. Glutamate. a-ketoglutarate.

Question 34

Proline pathway

Answer 34

Proline [proline dehydrogenase] glutamate-y semialdehyde [glutamate semialdehyde dehydrogenase] Glutamate = a-ketoglutarate

Question 35

Converted to ornithine which then undergo transamination to glutamate-y semialdehyde

Answer 35

Arginine

Question 36

Arginine pathway

Answer 36

Arginine [arginase] ornithine

Question 37

Non-oxidatively deaminated then hydrated and its imidazole ring cleaved to form ___________; formimino group is then transferred to TH4 to form ______ and ______.

Answer 37

Histidine. N-formiminoglutamate(figlu). N-formiminoTH4 & Glutamate.

Question 38

Histidine pathway

Answer 38

Histidine [histidinase] Urocanate [urocanase] 4-imidazolone-B-proprionate [imidazolone proprionate hydrolase] N-formiminoglutamate [glutamate formimino transferase] Glutamate = a-Ketoglutarate

Question 39

Can be used to detect folic acid deficiency

Answer 39

Excretion of FIGLU ff. a dose of histidine

Question 40

First reaction in its degradation is its hydroxylation to tyrosine

Answer 40

Phenylalanine

Question 41

Transaminated to p-hydroxyphenyl-pyruvate followed by concerted ring hydroxylation and side chain migration to form ______ with _____ as reductant; aromatic ring opens and is hydrolyzed to ______ and _______.

Answer 41

Homogentisate. Ascorbate. Fumarate & Acetoacetate.

Question 42

An important methyl donor

Answer 42

S-Adenosyl-methionine (SAM)

Question 43

Condenses with ATP to form SAM

Answer 43

Methionine

Question 44

Methionine to SAM pathway

Answer 44

Methionine+ATP [methionine adenosyl transferase] SAM

Question 45

In methionine, removal of methyl group forms ________ which is hydrolyzed to _______ & _______.

Answer 45

S-adenosylhomocysteine. Adenosine & Homocysteine.

Question 46

In methionine, homocysteine combines to serine to yield _______ which is subsequently forms ______ and _______.

Answer 46

Cystathione. Cysteine & a-ketobutyrate.

Question 47

In methionine, a-Ketobutyrate is degraded to _______ & then to ______.

Answer 47

Propionyl CoA. Succinyl CoA.

Question 48

Methionine pathway

Answer 48

Methionine- S adenosyl methionine- S adenosyl homocysteine- Homocysteine plus serine [cystathione synthase] Cystathione = cysteine and a-Ketobutyrate= proprionyl CoA

Question 49

Isoleucine is converted to

Answer 49

Propionyl CoA

Question 50

Valine is converted to

Answer 50

Methylmalonyl CoA

Question 51

Methionine is converted to

Answer 51

a-Ketobutyrate

Question 52

a-Ketobutyrate to Propionyl CoA to Methylmalonyl CoA to

Answer 52

Succinyl CoA

Question 53

Has several pathways for degradation but the pathway that proceed via the formation ______ predominates in mammalian liver.

Answer 53

Lysine. Saccharopine.

Question 54

Pathway of lysine involves

Answer 54

Transamination, oxidative decarboxylation and reactions similar to fatty acyl CoA oxidation. "TOF"

Question 55

Lysine pathway

Answer 55

Lysine- saccharopine- aminoadipate semialdehyde- aminoadipate- ketoadipate- glutaryl CoA- crotonyl CoA- B hydroxybutyryl coA- Acetoacetyl CoA- HMG CoA- Acetoacetate

Question 56

Initial reaction involves cleavage of indole ring with incorporation of 2 atoms of molecular oxygen by ________.

Answer 56

Tryptophan. Tryptophan oxygenase.

Question 57

In tryptophan, carbon atoms of side chain and aromatic ring completely degraded via

Answer 57

Kynurenine-anthranilate pathway

Question 58

An iron porphyrin metalloprotein. Inducible in the liver by adrenal corticosteroid and by tryptophan.

Answer 58

Tryptophan oxygenase

Question 59

Tryptophan oxygenase feedback is inhibited by

Answer 59

Nicotinic acid derivatives including NADPH

Question 60

Purely ketogenic AA. Degraded to _____ which is converted to _____ and ______.

Answer 60

Leucine. HMG CoA. Acetoacetate & Acetyl CoA.

Question 61

Brached chain AA

Answer 61

Leucine, Isoleucine and Valine "LIV"

Question 62

Shares the same first three reaction that employs a common enzyme. Resulting products are then catabolized by distinct pathways.

Answer 62

Branched chain AA

Question 63

Same first 3 reactions shared by Branched chain AA

Answer 63

-Transamination to corresponding a-Ketoacids -Oxidative decarboxylation to corresponding acyl CoA -Dehydrogenation by FAD to form a double bond "TOD"

Question 64

Almost always associated with AA catabolism rather than AA biosynthesis. Sufficient amount of AA whether essential or non essential are present in a well balanced diet.

Answer 64

Amino acidopathies

Question 65

Failure to catabolize AAs will result in accumulation of AA and its metabolites to the point that they become _____.

Answer 65

Toxic

Question 66

Defect in the catabolism of ______. Deficiency in the enzyme ________. Most striking manifestation is darkening of urine d/t the presence of homogentisate. Later develops arthritis and connective tissue pigmentation.

Answer 66

Alkaptonuria. Tyrosine. Homogentisate oxidase.

Question 67

Results in the inability to covert phenylalanine to tyrosine. Defect may be in the enzyme ________(classic PKU), ______ or ______. Major consequence is mental retardation.

Answer 67

PKU. Phenylalanine hydroxylase, Tetrahydrobiopterine synthase or Dihydrobiopterine synthase.

Question 68

Treatment for PKU

Answer 68

Diet low in phenylalanine

Question 69

Alternative pathways of phenylalanine catabolism

Answer 69

Phenylketonurics

Question 70

Defect in the intestinal and renal transport of neutral AA including tryptophan. Manifest with pellagra-like s/sx because of limited conversion of tryptophan to niacin.

Answer 70

Hartnup disease

Question 71

Defect in the absence of branched chain a-ketoacid Dehydrogenase. Odor of urine resembles maple syrup or burnt sugar. Brain damage develops unless promptly treated with ________.

Answer 71

Maple syrup urine disease. Diet low in BCAA.