Specialized Products of Amino Acids

Question 1

Tyrosine is converted to what? By what enzyme? What cofactors are needed?

Answer 1

DOPA;
Tyrosine hydroxylase;
Tetrahydrobiopterin (BH4)

Question 2

DOPA is converted to what? By what enzyme? What cofactors are needed?

Answer 2

Dopamine;
DOPA Decarboxylase;
PLP (Vit B6)

Question 3

Dopamine is converted to what? By what enzyme? What cofactors are needed?

Answer 3

Norepinephrine;
Dopamine B-hydroxylase
Vitamin C

Question 4

Noepinephrine is converted to what? By what enzyme? What cofactors are needed?

Answer 4

Epinephrine;
Phenylethanolamine N Methyl Transferase;
S-adenoysl methionone (SAM)

Question 5

A patient comes to you with spastic movements, tremors, loss of memory, mood disturbances and postural instability. You suspect he has ___________, which you know is a neurodegenerative disorder caused by a loss of ________ producing cells in the _________. Tests confirm your suspicion and so you administer _______. This drug is converted to ________ in the brain and improves his symptoms.

Answer 5

Parkinsons disease;
Dopamine;
Basal ganglia;
L-Dopa;
Dopamine

Question 6

Peripheral dopamine formation must be inhibited by administration of what?

Answer 6

Dopa decarboxylase inhibitor along with the L-Dopa

Question 7

Norepinephrine and epinephrine are degraded by _____and _____ to form______.

Answer 7

MAO (monoamine oxidase)
COMT (Catechol O-methyl transferase
VMA (Vanillyl Mandelic acid - excreted in urine)

Question 8

Besides degrading Norepinephrine and Epinephrine to VMA, MAO and COMT degrade Dopamine as well to:

Answer 8

HVA (Homovanillic acid -excreted in urine)

Question 9

What is Pheochromocytoma?

Answer 9

Overproduction of catecholamines by an adrenal medulla tumor.

Question 10

Serotonin is also known as what?

Answer 10

5-hydroxy tryptamine

Question 11

Serotonin is synthesized in what?

Answer 11

Gut
Platelets
CNS

Question 12

Serotonin is synthesized from what?

Answer 12

Tryptophan

Question 13

Serotonin is metabolized to what? By what enzyme?

Answer 13

5-HIAA (5-hydroxyindole acetic acid);

MAO

Question 14

What is diagnostically characteristic of Carcinoid syndrome?

Answer 14

Increased 5-HIAA in urine;

because it is caused by a tumor of serotonin producing cells in the GIT (APUD cells)

Question 15

Melatonin is derived from what?

Answer 15

Serotonin (5-Hydroxy Tryptamine)

Question 16

Which reactions require Tetrahydrobiopterin?

Answer 16

–Phenylalanine hydroxylase(converts Pheto Tyr)
–Tyrosine hydroxylase(converts Tyr to DOPA)
–Tryptophan hydroxylase(converts Trpto 5-hydroxy tryptophan)

Question 17

Deficiency of ____________or__________ result in hyperphenylalaninemia& decreased synthesis of neurotransmitters (catecholamines, serotonin).

Answer 17

Dihydrobiopterin synthase

Dihydrobiopterin reductase

Question 18

What type of neurotransmitter is GABA?

Answer 18

Inhibitory

in CNS

Question 19

GABA stands for

Answer 19

Gamma amino butyric acid

Question 20

Glutamic acid (Glutamate) is converted to GABA using what enzyme? What co-factor is required?

Answer 20

Glutamate Decarboxylase

PLP

Question 21

What cells are involved with GABA reuptake in the CNS?

Answer 21

Glial cells

Question 22

Histidine is converted to Histamine by what enzyme? Requiring which cofactor?

Answer 22

Amino Acid Decarboxylase

PLP

Question 23

Creatine can be synthesized from what?

Answer 23

Arginine,
Glycine
SAM (S-adenosyl Methionine)

Question 24

When muscle is resting, creatine…

Answer 24

accepts P groups from ATP

done by Creatine PK

Question 25

When muscle is contracting, creatine…

Answer 25

donates P groups to ADP

done by Creatine PK

Question 26

What is creatine converted to?

Answer 26

Creatinine (spontaneous)

Question 27

Acute or chronic renal failure does what to serum creatinine levels?

Answer 27

Elevate

Question 28

What does Nitric oxide synthase catalyze?

Answer 28

Arginine —-> NO

Citrulline is given off

Question 29

Albinism is a deficiency of what enzyme?

Answer 29

Tyrosinase

deficient conversion of tyrosine to melanin

Question 30

Glutathione is a tripeptide made up of what three enzymes?

Answer 30

Glutamate (Glutamic acid)
Cysteine
Glycine

Question 31

Glutathione reductase functions to reduce ______ back to 2 _______ and requires ______ as an electron source.

Answer 31

GSSG
GSH
NADPH