Protein and AA Metabolism Flashcards Preview

MCM Exam 1 > Protein and AA Metabolism > Flashcards

Flashcards in Protein and AA Metabolism Deck (26):
1

Essential Amino Acids

W, F, M
R, H, K
L, I, V
T

2

Ketogenic AAs

L, K
Become acetyl - CoA or acetoacetate

3

Glucogenic and Ketogenic AAs

I, W, F, Y, T
Can become ketogenic or glucogenic (pyruvate or TCA intermediates --> GNG)

4

AAs that are metabolized to a-ketoglutarate

Q, R, H, P ----> E ----> a-KG

5

AAs that are metabolized to succinyl-CoA

T, M, I, V ----> propionyl CoA ----> succinyl CoA

6

AAs that are metabolized to fumarate

F, Y, D

7

AAs that are metabolized to OAA

N, D

8

ALT (alanine aminotransferase)

Catalyzes pyruvate + glutamate ---> alanine + a-KG

9

AST (aspartate aminotransferase)

Catalyzes OAA + glutamate ---> aspartate + a-KG

10

GA (glutamate aminohydrolase)

Catalyzes glutamine + H2O ---> glutamate + NH3

11

Transaminases require:

Coenzyme PLP (pyridoxyl-5'-phosphate) a derivative of Vit B6.

12

Cause of Homocsytinuria

Cystathione b-synthase does not work, causing build up of Homocysteine (in the Met pathway). Requires PLP as a coenzyme.

13

Homocystinuria

Cystathione b-synthase is defective or a Vit B6 deficiency can cause it.
Most affected systems include the eye, skeletal, CNS, and vascular system.

14

BCAAs (3)

L, I, V

15

MSUD

Deficient in BCKD, so the pt cannot breakdown BCAAs.
Causes maple syrup smell of urine. Can cause blood accumulation causing toxic affects on brain function and eventually mental retardation.
Diet must limit BCAAs, and can be restored with thiamine supplements in mild forms.

16

PKU

Defect in phenylalanine hydroxylase (PAH). Phe cannot be broken down to Tyr and subsequent protein, catecholamine, thyroxine or melanin synthesis cannot happen.
Phe insteade converted to phenylpyruvate then to phenyllactate and phenylacetone (causes the smell).
Can cause neurotransmission problems and impair brain function.

17

Trp (W) derivatives (2)

1. serotonin ---> melatonin
2. niacin ---> NAD(P)+

18

Ser (S) derivative (1)

1. ACh

19

Tyr (Y) derivatives (3)

1. Dopamine ---> Norepi ---> Epi
2. Thyroid hormones
3. Melanin

20

Glu (E) derivative (1)

1. GABA

21

Albanism

Lack of melanin. Tyr to melanin conversion is blocked due to defect of tyrosinase.

22

Removing N from brain

Brain: removed as a-KG --> E then E ---> Q then to liver Q ---> E (ammonia released to urea cycle).

23

Removing N from muscle

A from muscle to blood to liver. A ---> E to the urea cycle (regenerate a-KG).

24

Urea Cycle

Draw cycle

25

Phsosphocreatine

Used quickly to generate ATP. Stored in muscle, brain and sperm.

26

Creatine

Made of R, G, M
Used to diagnose kidney dysfunction and muscle degeneration.