Sulfur and Aromatic AA Metabolism Flashcards

1
Q

Name 3 major products that Trp is used to make.

A
  1. serotonin
  2. melatonin
  3. niacin
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2
Q

Where are Met residues usually found?

A

in the center of the protein

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3
Q

What aa is used to produce S-adenosylmethionine (SAM), a high energy storage unit?

A

methionine

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4
Q

How is hyperhomocysteinemia treated?

A
  • folate
  • B6
  • B12
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5
Q

_____ is hydroxylated by phenylalanaine hydroxylase to produce Tyr using BH4 as a cofactor.

A

Phe

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6
Q

What is unique about cysteine?

A

it can form disulfide bonds –> strength

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7
Q

What is cysteinuria?

A

kidney stones –> renal failure due to defective cysteine transporter –> crystallization in urea

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8
Q

What is a tyrosinemia?

A

a defect in tyrosine degradation

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9
Q

Is methionine essential?

A

yes

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10
Q

Phe and Tyr are metabolized to _____ or ______.

A
  • fumarate
  • acetoacetate
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11
Q

What are the 2 sulfur containing aa’s?

A
  1. methionine
  2. cysteine
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12
Q

Phe is hydroxylated by phenylalanaine hydroxylase to produce _____ using BH4 as a cofactor.

A

Tyr

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13
Q

What can elevated homocysteine lead to?

A
  • vascular disease
  • impaired wound healing
  • CA
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14
Q

What is the tx for homocystinuria?

A

vitamin B6

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15
Q

Trp is metabolized to ____ or _____.

A
  • pyruvate
  • acetyl-CoA
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16
Q

_____ is metabolized to pyruvate or acetyl-CoA.

A

Trp

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17
Q

Tyr is hydroxylated by ______ to produce DOPA using BH4.

A

tyrosine hydroxylase

18
Q

What is S-adenosylmethionine (SAM) used for?

A
  • methylation (DNA, proteins, NE–>epi)
  • epigenetics
  • host defense
  • CA development
  • fetal development
  • tx for depression
19
Q

_____ is hydroxylated by tyrosine hydroxylase to produce DOPA using BH4.

A

Tyr

20
Q

This is a defect in phenylalanine hydroxylase –> build up of alternate byproducts (phenylacetate, phenylpyruvate).

A

phenylketonuria (PKU)

21
Q

This disease causes kidney stones –> renal failure due to defective cysteine transporter –> crystallization in urea.

A

cysteinuria

22
Q

What is tetrahydrofolate (THF) synthesized from?

A

vitamin B9 (folic acid)

23
Q

What aa can form disulfide bonds?

A

cysteine

24
Q

Phe is hydroxylated by ______ to produce Tyr using BH4 as a cofactor.

A

phenylalanaine hydroxylase

25
Q

DOPA can be metabolized into _____ and _____.

A
  • catecholamines (DOPA, DA, NE, epi)
  • melanin
26
Q

Where are Cys residues typically found?

A

in the active site

27
Q

What is phenylketonuria (PKU)?

A

a defect in phenylalanine hydroxylase –> build up of alternate byproducts (phenylacetate, phenylpyruvate)

28
Q

What is hyperhomocysteinemia?

A

elevated levels of homocysteine (bad)

29
Q

This is a defect in cystathione-b-synthase (CBS) so homocysteine cannot be converted to cystathione –> mental retardation, osteoporosis, vascular disease.

A

homocystinuria

30
Q

Name 3 aromatic aa’s.

A
  1. tryptophan
  2. phenylalanine
  3. tyrosine
31
Q

What is homocystinuria?

A

a defect in cystathione-b-synthase (CBS) so homocysteine cannot be converted to cystathione –> mental retardation, osteoporosis, vascular disease

32
Q

Is cysteine essential?

A

no

33
Q

What is a cofactor for trp hydroxylation?

A

tetrahydrobiopterin (BH4)

34
Q

___ and ____ are metabolized to fumarate or acetoacetate.

A
  • Phe
  • Tyr
35
Q

Tyr is hydroxylated by tyrosine hydroxylase to produce _____ using BH4.

A

DOPA

36
Q

What is required for the converstion of homocysteine –> methionine?

A
  • THF
  • vitamin B12
37
Q

This peptide’s functions include:

  • it allows for proper folding and disulfide bond formation
  • a redox buffer
  • a cofactor
  • protects against ROS
A

glutathione (GSH)

38
Q

What is unique about methionine?

A

it’s used to produce S-adenosylmethionine (SAM) –> high energy storage unit

39
Q

What is the tx for cysteinuria?

A

acetazolamide

40
Q

What is the function of glutathione (GSH)?

A
  • it allows for proper folding and disulfide bond formation
  • a redox buffer
  • a cofactor
  • protects against ROS
41
Q

What is the term for elevated levels of homocysteine?

A

hyperhomocysteinemia