Amino Acids - Specialized Products

Question 1

Tyr is starting amino acids for???

Answer 1

Catacholamines - dopamine, norepinephrine, epinephrine; pigment - melanin; hormones - T3 and T4

Question 2

rate limiting step of catacholamines

Answer 2

Tyr hydroxylase whose product is DOPA

Question 3

where do you find tyr hydroxylase

Answer 3

CNS, sympathetic ganglia, adrenal medulla

Question 4

what is albinism

Answer 4

deficiency of melanin (made from Tyr using Tyrosinase in melanocytes) in skin, hair, and eyes

Question 5

albinism that affects the eye is called

Answer 5

oculocutaneous albinism

Question 6

diseases associated with loss of dopamine producing cells in the basal ganglia

Answer 6

Parkinson’s Disease (4th most common disorder in elderly)

Question 7

characteristics of Parkinson’s

Answer 7

movement disorders: spasticity and tremors, loss of memory, mood disturbances, postural instability

Question 8

How do you treat Parkinson’s

Answer 8

administer L-DOPA and dopa decarboxylase inhibitor (Carbidopa)

Question 9

why administer L-DOPA to parkinson’s patient instead of dopamine

Answer 9

L-DOPA can cross the BBB but dopamine cannot

Question 10

why administer L-DOPA with Carbidopa

Answer 10

it increases the half life of L-DOPA in the GIT and peripheral tissues – carbidopa can’t cross the BBB though

Question 11

product of degradation of noepinephrine and epinephrine

Answer 11

vanillylmandelic acid (VMA) and other products using Monoamine oxidase (MAO) and catacholamine O-methyltransferase (COMT)

Question 12

how do you test for level of catecholamines noepinephrine and epinephrine produced

Answer 12

check urinary VMA levels

Question 13

what is the product of degradation of dopamine

Answer 13

homovanillic acid (HVA) using MAO and COMT

Question 14

disease associated with overproduction of catecholamines

Answer 14

pheochromocytoma

Question 15

symptoms of pheochromocytoma

Answer 15

headache, sweating, tachycardia

Question 16

what regulates basal metabolic rate

Answer 16

thyroid hormone (formed from Tyr and iodine)

Question 17

precursor for serotonin and melatonin

Answer 17

tryptophan

Question 18

degradation of serotonin is done by…?

Answer 18

monoamine oxidase A (MAO-A)

Question 19

what is serotonin for

Answer 19

pain perception, sleep wake cycle, regulation of mood and appetite, and blood pressure and temp

Question 20

what is melatonin for

Answer 20

sleep inducing hormone, regulation of circadian rhythm, light/dark cycle, SAD

Question 21

increased 5 HIAA in urine is marker for?

Answer 21

carcinoid syndrome

Question 22

symptoms of carcinoid syndrome

Answer 22

cutaneous flushing, diarrhea, bronchospasm

Question 23

relationship between Glu and GABA

Answer 23

GABA formed as a result of decarboxylation of Glu using glutamate decarboxylase and PLP

Question 24

relationship between histidine and histamine

Answer 24

histamine formed as a result of decarboxylation of histidine using histidine decarboxylase and PLP

Question 25

purpose of histamine

Answer 25

vasodilator, allergic rxn, inflammatory responses, gastric secretion, neurotransmission

Question 26

what do anti-histamine do?

Answer 26

prevent histamine signaling so basically receptor blockers

Question 27

what is the precursor amino acid for NO synthesis

Answer 27

arginine (product is L-citrulline) reaction requires NADPH, O2, BH4, FAD, FMN

Question 28

nitroglycerine treatment results in...

Answer 28

vasodilation of coronary blood vessels and improvement of blood flow to heart

Question 29

where do you find creatine

Answer 29

muscle, heart, and brain

Question 30

where does synthesis of creatine occur

Answer 30

starts in kidney then continues in liver before being transported via blood to muscle, heart, and brain

Question 31

what does creatine do?

Answer 31

accept P from ATP when muscle is resting and can donate P to ADP when muscle is contracting

Question 32

levels of CPK/ CK-MB indicator of?

Answer 32

indicator of myocardial ischaemia/ myocardial damage (heart attack)

Question 33

serum creatinine levels are indicator of...?

Answer 33

renal function - levels rise in acute or chronic renal failure

Question 34

glutathione contains what?

Answer 34

glu, cys, gly

Question 35

glutathione is impo for

Answer 35

detoxification of H2O2 esp in RBC, protects RBC from oxidative stress, cofactor for many enzymatic rxns, aid in rearragement of protein disulphide bonds, can be conjugated to drugs to make them more water soluble, reducing agent

Question 36

reactions that need tetrahydrobiopterin (BH4)

Answer 36

phenylalanine hydroxylase (Phe to Tyr), Tyr hydroxylase (Tyr to DOPA), Trp hydroxylase (trp to 5 hydroxy trp), and NO synthase