Amino Acid Oxidation Flashcards

1
Q

What are the two major categories of amino group carbon skeletons?

A

Glucogenic

Ketogenic

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2
Q

What does it mean to be glucogenic?

A

TCA Cycle intermediates that can be shunted to gluconeogenesis

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3
Q

What does it mean to be ketogenic?

A

AcetylCoA derivatives that can be used for ketone body synthesis

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4
Q

Can we make glucose from proteins?

A

Yes, fairly easily

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5
Q

What does breakdown of Methionine synthesize?

A

Cysteine

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6
Q

What does the breakdown of Phenylalanine synthesize?

A

Tyrosine

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7
Q

What 4 glucogenic amino acids can form pyruvate?

A

Ala
Ser
Cys
Trp

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8
Q

What 2 glucogenic aa’s can form Oxaloacetate?

A

Asn

Asp

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9
Q

How many carbons are in amino acids that form pyruvate?

A

3 Carbons form the alpha-keto acid pyruvate

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10
Q

How many carbons are in amino acids that form oxaloacetate?

A

4 Carbons form the alpha-keto acid oxaloacetate

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11
Q

What 5 glucogenic amino acids can form alpha-KG?

A
Gln
Pro
Arg
His
Glu
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12
Q

How many carbons are in amino acids that form alpha-KG?

A

5 Carbons form alpha-KG but they are first funneled to Glu

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13
Q

What kind of glucogenic/ketogenic aa’s can form SuccinylCoA and AcetylCoA?

A

Branched Chain Amino Acids

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14
Q

What are the branched chain amino acids?

A

Ile
Val
Leu

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15
Q

What does Val form when oxidized?

A

PropionylCoA

Strictly glucogenic

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16
Q

What does Ile form when oxidized?

A

PropionylCoA and AcetylCoA

Both glucogenic and ketogenic

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17
Q

What does Leu form when oxidized?

A

Acetoacetate and AcetylCoA

Strictly ketogenic

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18
Q

Where does transamination of branched chain aa’s occur?

A

In muscle, kidney and brain

NOT THE LIVER

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19
Q

Which steps of oxidation do the branched chain amino acids share?

A

The first 2 steps

Separate after dehydrogenase complex

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20
Q

What two glucogenic aa’s can form SuccinylCoA exclusively?

A

Met

Thr

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21
Q

What do Met and Thr yield before being converted to propionylCoA?

A

alpha-ketoburyate

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22
Q

What is the byproduct of SuccinylCoA conversion from alpha-ketobutyrate?

A

Cysteine

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23
Q

What is PropionylCoA converted too?

A

SuccinylCoA

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24
Q

What two major cofactors are used when converting PropionylCoA to SuccinylCoA?

A

Biotin (Vit. B7)

Cobalamin

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25
Q

What strictly ketogenic aa’s can be used to form AcetylCoA?

A

Leu

Lys

26
Q

What is Lys converted too?

A

AcetoacetocylCoA

27
Q

Are Leu and Lys the only strictly ketogenic aa’s?

A

YES!!!

28
Q

What type of aa’s can be used to form Fumarate and AcetylCoA?

A

Aromatic Amino Acids

29
Q

What are the aromatic amino acids?

A

Phe
Tyr
Trp

Aromatics are both glycogenic and ketogenic

30
Q

What is Phenylketonuria?

A

An autosomal recessive disease resulting from phenylalanine hydroxylase deficiency

31
Q

How does one treat Phenylketonuria?

A

With a low phenylalanine diet until adolescence

32
Q

What does lack of treatment for Phenylketonuria result in?

A

Severe mental retardation

33
Q

What is Tetrahydrobiopterin?

A

A cofactor in many hydroxylase reactions as well as pathways that produce some major NT’s

34
Q

What is Alkaptonuria?

A

The first described genetic disease

Defect in homogentisate oxidase

35
Q

What are the symptoms of Alkaptonuria?

A

Ochronosis

Arthritis like symptoms

36
Q

What is Ochronosis?

A

A bluish blackish discoloration of connective tissues due to buildup of acid (Can be found in eye)

37
Q

What deficiency results in Albinism?

A

A deficiency in tyrosinase which results in decreased melanin production

38
Q

What is glycine converted into in bacteria?

A

Gly > Ser > Pyr

39
Q

What is glycine converted into in humans?

A

CO2 and NH4+

40
Q

What 4 aa’s are both glycogenic and ketogenic?

A

3 aromatics: Phe, Tyr, Trp

1 branched chain: Ile

41
Q

What 2 acids are strictly ketogenic?

A

Leu

Lys

42
Q

What is Phenylketonuria?

A

Defect in phenylalanine hydroxylase

43
Q

What is Maple Syrup Urine Disease?

A

Defect in branched chain aa DH

44
Q

What is Methylmalonic Acidemia?

A

Defect in methylmalonylCoA mutase

45
Q

What is Homocystinuria?

A

Defect in cystathione synthase

46
Q

What is carrier status?

A

Preconception testing of parents

47
Q

What is pre-implantation screening?

A

Test IVF embryos prior to implantation

48
Q

What are the pre-natal forms of screening for inborn errors of metabolism?

A

Chorionic villus
Amniocentesis
Cordocentesis

49
Q

When do you use the Chorionic Villus?

A

10-12th week of pregnancy

50
Q

When do you use Amniocentesis?

A

15-18th week of pregnancy

51
Q

When do you use Cordocentesis?

A

After the 17th week of pregnancy

52
Q

What was the first screening used on newborns?

A

PKU screening in 1966

53
Q

What percent of CA newborn are screened for 86 different disorders today?

A

99%

54
Q

What enzyme cofactors are important in 1-carbon transfers?

A

Biotin
THF
SAM

55
Q

How does biotin transfer carbons?

A

Transfers CO2

56
Q

How does THF transfer carbons?

A

Transfers Carbons in various oxidation states

57
Q

How does SAM transfer carbons?

A

Transfers methyl groups

58
Q

What is the common name of B6 and what is it’s function?

A

Pyridoxine

Transaminations

59
Q

What is the common name of B7 and what is it’s function?

A

Biotin
Carries activated CO2
Carboxylase reactions

60
Q

What is the common name of B9 and what is it’s function?

A

Folate

Precursor for THF for methyl group transfers

61
Q

What is the common name of B12 and what is it’s function?

A

Cobalamin
MMACoA > SucCoA
homocys > met