Amino Acid Oxidation Flashcards Preview

MCBM Exam 4 Kat > Amino Acid Oxidation > Flashcards

Flashcards in Amino Acid Oxidation Deck (61):
1

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

Glucogenic
Ketogenic

2

What does it mean to be glucogenic?

TCA Cycle intermediates that can be shunted to gluconeogenesis

3

What does it mean to be ketogenic?

AcetylCoA derivatives that can be used for ketone body synthesis

4

Can we make glucose from proteins?

Yes, fairly easily

5

What does breakdown of Methionine synthesize?

Cysteine

6

What does the breakdown of Phenylalanine synthesize?

Tyrosine

7

What 4 glucogenic amino acids can form pyruvate?

Ala
Ser
Cys
Trp

8

What 2 glucogenic aa's can form Oxaloacetate?

Asn
Asp

9

How many carbons are in amino acids that form pyruvate?

3 Carbons form the alpha-keto acid pyruvate

10

How many carbons are in amino acids that form oxaloacetate?

4 Carbons form the alpha-keto acid oxaloacetate

11

What 5 glucogenic amino acids can form alpha-KG?

Gln
Pro
Arg
His
Glu

12

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

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

13

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

Branched Chain Amino Acids

14

What are the branched chain amino acids?

Ile
Val
Leu

15

What does Val form when oxidized?

PropionylCoA
Strictly glucogenic

16

What does Ile form when oxidized?

PropionylCoA and AcetylCoA
Both glucogenic and ketogenic

17

What does Leu form when oxidized?

Acetoacetate and AcetylCoA
Strictly ketogenic

18

Where does transamination of branched chain aa's occur?

In muscle, kidney and brain

NOT THE LIVER

19

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

The first 2 steps

Separate after dehydrogenase complex

20

What two glucogenic aa's can form SuccinylCoA exclusively?

Met
Thr

21

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

alpha-ketoburyate

22

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

Cysteine

23

What is PropionylCoA converted too?

SuccinylCoA

24

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

Biotin (Vit. B7)
Cobalamin

25

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

Leu
Lys

26

What is Lys converted too?

AcetoacetocylCoA

27

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

YES!!!

28

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

Aromatic Amino Acids

29

What are the aromatic amino acids?

Phe
Tyr
Trp

Aromatics are both glycogenic and ketogenic

30

What is Phenylketonuria?

An autosomal recessive disease resulting from phenylalanine hydroxylase deficiency

31

How does one treat Phenylketonuria?

With a low phenylalanine diet until adolescence

32

What does lack of treatment for Phenylketonuria result in?

Severe mental retardation

33

What is Tetrahydrobiopterin?

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

34

What is Alkaptonuria?

The first described genetic disease
Defect in homogentisate oxidase

35

What are the symptoms of Alkaptonuria?

Ochronosis
Arthritis like symptoms

36

What is Ochronosis?

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

37

What deficiency results in Albinism?

A deficiency in tyrosinase which results in decreased melanin production

38

What is glycine converted into in bacteria?

Gly > Ser > Pyr

39

What is glycine converted into in humans?

CO2 and NH4+

40

What 4 aa's are both glycogenic and ketogenic?

3 aromatics: Phe, Tyr, Trp
1 branched chain: Ile

41

What 2 acids are strictly ketogenic?

Leu
Lys

42

What is Phenylketonuria?

Defect in phenylalanine hydroxylase

43

What is Maple Syrup Urine Disease?

Defect in branched chain aa DH

44

What is Methylmalonic Acidemia?

Defect in methylmalonylCoA mutase

45

What is Homocystinuria?

Defect in cystathione synthase

46

What is carrier status?

Preconception testing of parents

47

What is pre-implantation screening?

Test IVF embryos prior to implantation

48

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

Chorionic villus
Amniocentesis
Cordocentesis

49

When do you use the Chorionic Villus?

10-12th week of pregnancy

50

When do you use Amniocentesis?

15-18th week of pregnancy

51

When do you use Cordocentesis?

After the 17th week of pregnancy

52

What was the first screening used on newborns?

PKU screening in 1966

53

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

99%

54

What enzyme cofactors are important in 1-carbon transfers?

Biotin
THF
SAM

55

How does biotin transfer carbons?

Transfers CO2

56

How does THF transfer carbons?

Transfers Carbons in various oxidation states

57

How does SAM transfer carbons?

Transfers methyl groups

58

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

Pyridoxine
Transaminations

59

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

Biotin
Carries activated CO2
Carboxylase reactions

60

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

Folate
Precursor for THF for methyl group transfers

61

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

Cobalamin
MMACoA > SucCoA
homocys > met