Amino Acid Metabolism Flashcards Preview

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Flashcards in Amino Acid Metabolism Deck (27):
1

Extracellular Proteolytic Enzymes Control

Secreted as inactive zymogens; activated by proteolytic cleavage: Trypsin activates chymotrypsinogen.

2

Essential Amino Acids

Phenylalanine
Valine
Thryptophan
Threonine
Isoleucine
Methionine
Histidine
Arginine
Leucine
Lysine
Glutamine

3

What are the Ketogenic Amino Acids?
What are they metabolized into?

Leucine and Lysine. They are metabolized into Acetyl CoA and acetoacetate.

4

What are the glycogenic Amino Acids?
To what cycle do they contribute?

most of them. They participate in the TCA Cycle intermediates.

5

What are the Amino Acids metabolized and added to alpha-Ketoglutarate of TCA?

"PHAG"
Proline
Histidine
Arg
Gln
These 4 are converted to Glu which enters the TCA cycle.

6

Succinyl CoA Amino Acids add ons.
Which of these are branched?

"I think My Vagina Succs"
Thr
Met
Ile
Val
All of them convert to Propionyl CoA, which converts to Methylmalonyl CoA, which converts to Succinyl CoA.

Ile and Val are branched.

7

Acetyl CoA Amino Acid Add on

Leucine. Barched AA, causes Maple syrup Urine Disease.

8

What AA is metabolized and introduced to Fumarate in TCA?

Phenylalanine is converted to Tyrosine by Phenylalanine Hydroxylase. Tyrosine is converted into Fumarate down the line.

9

Phenylalanine Hydroxylase function

Converts Phenylalanine to Tyrosine.

10

What AA is metabolized to Oxaloacetate?

Asn to Asp to Oxaloacetate
"OX with a big AAsp"

11

What is Phenylketonuria and what causes it?

Is caused by defects in the Phenylalanine Hydroxylase. Instead of being converted to Tyrosine, it is converted to Phenylpyruvate and then to Phenyllactate and Phenylacetate.

12

What are the Tryptophan derivatives?

Trp is converted to 5hydroxytrp, which is decarboxylated to Serotonin- can convert to Melatonin.

13

What are Tyrosine derivatives?

Tyrosine is converted to Dopamine, which can be further converted to Norepinephrine and Epinephrine.
Can also be converted into T3 and T4
Can also be converted to Melanin.

14

What causes Albinism?

Conversion of Tyrosine to Melanin is blocked due to defects in enzyme Tyrosinase.

15

How is Ammonia toxicity caused?

Caused by excessive Ammonia due to disorders in the Urea Cycle (Ornithine cycle).

16

What Amino Acid makes Ornithine?

Arginine.

17

What Amino Acids make up Creatine?

Met, Arg, Gly

18

What kind of proteins are degraded during proteasomal degradation?

Polyubiquinated proteins. This is a selective process.

19

What are the 2 anaplerotic reactions of TCA cycle?

1. Degradation of amino acids
2. Decarboxylation of Pyruvate.

20

What causes Homocystinuria?

Deficiency in vitamins: B6, 12, or Biotin. Also genetic defects in enzyme: Cystathionine-beta-synthase. This causes defective metabolism of homocysteine.

21

Function of enzyme Cystathionine-beta-synthase?

Converts Homocysteine to cystathionine during the Met metabolism.

22

What are the branched chain amino acids?

LIV: Leucine, Isoleucine, Valine.

23

Maple Syrup Urine Disease

Rare autosomal disease resulting from deficiency in the Branched -chain alpha Keto acid dehydrogenase complex(BCKD) activity which results in branched-chain Ketoaciduria.

24

What enzyme is the Rate Limiting step of Ornithine?

Carbamoyl Phosphate Synthetase. NAG is an activator.

25

What are Transaminases/Aminotransaminases?
What co-enzyme is required?

They transfer an amino group to a alpha ketoacid.
PLP(derivative of B6)

26

Ammonia is removed as Glu and Gln in the_______

Brain

27

Ammonia is removed as Gln and Ala in the________

Tissues