Amino Acid Oxidation

Question 1

What can the 7 intermediates produced from the aa be subdivided into

Answer 1

1. Glucogenic: TCA cycle intermediates that can be shunted to gluconeogenesis
2. Ketogenic: AcetylCoA derivates that can be used for ketone body synthesis.

Question 2

18/20 aa are at least partially______. 4/20 glucogenic and ketogenic products include ____2/20 are purely ketogenic.

Answer 2

glucogenic. 3 aromatics + Ile; Leu and Lys

Question 3

Methionine breaks down into ____. Phenylalanine breaks down into ______

Answer 3

cysteine; tyrosine

Question 4

The key to interconversion of aa & carbs lies in the interrelationship between aa and:

Answer 4

alpha keto acids

Question 5

What are the 7 metabolites of aa metabolism in glucogenic and ketogenic

Answer 5

Glucogenic:

1. pyruvate
2. oxaloacetate
3. alpha KG
4. fumerate
5. propionylCoA

Ketogenic:

6. acetoacetyl CoA
7. acetylCoA

Question 6

Which aa form into pyruvate

Answer 6

1. Alanine
2. Serine
3. Cysteine
4. Tryptophan

Question 7

3C aa form a 3 C alpha keto acid to make

Answer 7

pyruvate

Question 8

What are the 4C aa that are metabolized to make oxaloaceate

Answer 8

1. Asparagine

2. Aspartate

Question 9

What are the 5C aa that are metabolized to make alpha keto Glutarate

Answer 9

1. Glutamine
2. Proline
3. Argenine
4. Histidine
5. Glutamate

Question 10

Which branched chain aa make up succyinyl CoA and acetyl CoA

Answer 10

1. Ile
2. Valine
3. Leucine

Question 11

Valine gets converted to propionyl CoA which means its strictly

Answer 11

glucogenic

Question 12

Ile gets converted to propionylCoA + acetylCoA which means its both:

Answer 12

glucogenic and ketogenic

Question 13

Leu gets converted to acetoacetate which means its strictly

Answer 13

ketogenic

Question 14

Branched chain aa share the first steps of:

Answer 14

oxidation. Get transaminated via branched chain aminotransferase

Question 15

Which aa make up succinylCoA

Answer 15

1. Methionine

2. Threonine

Question 16

Breakdown of methionine produces:

Answer 16

cysteine

Question 17

Met & Thr yield alpha keto butyrate that is converted to

Answer 17

propionylCoA.

Question 18

PropionylCoA gets converted to:

Answer 18

succinylCoA

Question 19

What does methlmalonyl CoA mutase need

Answer 19

cobalmin (B12)

Question 20

What is munechausen syndrome by proxy

Answer 20

making people get purposefully sick to get attention

Question 21

What are the two aa that are stricly ketogenic

Answer 21

Lycine and leucine

Question 22

Which aa make acetylCoA

Answer 22

leucine and lysine

Question 23

what aa make fumarate and acetylCoA

Answer 23

aromatic aa:

1. Phe
2. Tyr
3. Trp

Question 24

aromatic aa are both glucogenic and

Answer 24

ketogenic

Question 25

What enzyme is required in Phe metabolism. What can result when you have deficiency of this enzyme

Answer 25

phenylalanine hydroxylase. PKU

Question 26

What is the enzyme needed in homogentisate

Answer 26

homogentisate 1, 2 dioxygenase. Alkaptonuria can result if deficient.

Question 27

what is PKU

Answer 27

1. autosomal recessive disease 2. deficiency in phenylalaline hydroxylase 3. all newborns tested at birth 4. treatment req low phenylalaline diet until adolescene 5. lack of treatment results in severe mental retardation.

Question 28

What is a cofactor in many hydroxylase reactions.

Answer 28

Tetrahydrobiopterin. IMportant for neurotransmitters.

Question 29

what does alkaptonuria cause

Answer 29

pigment buildup throughout the body and arthiritis like symptoms.

Question 30

a deficiency in what enzyme results in albinism

Answer 30

tyrosinase

Question 31

In humans what is glycine converted to

Answer 31

CO2 and NH4

Question 32

In liver, what can serve as a substrate for lactate dehydrogenase and gets converted to oxalate

Answer 32

glyoxylate

Question 33

what is the major component of kidney stones

Answer 33

Calcium oxalate

Question 34

which aa are both glucogenic and ketogenic

Answer 34

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

Question 35

Which 2 aa are strictly ketogenic

Answer 35

leucine and lysine

Question 36

What are inborn errors of metabolism

Answer 36

1. PKU: defect in phylalanine hydroxylase 2. Alkaptonuria: defect in homogentisate oxidase 3. maple syrup urine disease: defect in branched chain amino acid DH 4. methylmalonic acidemia: defect in methylmalonylCoA mutase 5. Homocystinuria: defect in cystathione synthase

Question 37

How do you screen for inborn errors of metabolism

Answer 37

1. carrier status: preconception testing of parents 2. pre-implantation: test IVF embryos prior to implantation 3. Pre natal: Chorionic villus (10-12 week of pregnancy), amniocentesis (15-18 week of pregnancy) cordocentesis (after 17th week of pregnancy)