Misc. Proteins

Question 1

What three amino acids contribute to creatinine?

Answer 1

glycine, arginine and ornithine

Question 2

Where does the nitrogen in creatinine come from?

Answer 2

guanidinoacetate

Question 3

What is the function of creatinine phosphate?

Answer 3

energy reserve for muscles

Question 4

Specifically, how is this accomplished?

Answer 4

creatine phosphate can phosphorylate ADP to ATP

Question 5

How is creatinine formed?

Answer 5

self cyclization

Question 6

Where is creatinine formed and released from?

Answer 6

muscle cells

Question 7

What co-factor does phenylalanine hydroxylase require?

Answer 7

THBtn

Question 8

Thyroid hormones are iodinated versions of what?

Answer 8

tyrosine

Question 9

What is the function of thyroid peroxidase?

Answer 9

iodination of tyrosine

Question 10

Where is thyroglobulin degraded? What does this release?

Answer 10

lysosomes

T3 and T4

Question 11

What is the molecular function of tyrosinase?

Answer 11

converts tyrosine to DOPA and DOPA to dopaquinone

Question 12

Where does melanin synthesis begin?

Answer 12

golgi of melanocytes

Question 13

What is dopaquinone synthesized into?

Answer 13

melanin

Question 14

What is the main function of melanin?

Answer 14

protect against UV radiation

Question 15

What tissues are melanocytes found in?

Answer 15

skin and hair follicles

Question 16

Albinism is caused by what?

Answer 16

loss of tyrosinase activity

Question 17

What two products are derived from tryptophan?

Answer 17

serotonin and melatonin

Question 18

What two tissues are rich in serotonin?

Answer 18

platelets and GI tract

Question 19

What two steps are down to tryptophan to make serotonin?

Answer 19

hydroxylation and decarboxylation

Question 20

What enzyme hydroxylates tryptophan?

Answer 20

tryptophan hydroxylase

Question 21

What co-factor is required for tryptophan hydroxylase?

Answer 21

THBtn

Question 22

What is the first step in the conversion of serotonin to melatonin?

Answer 22

N-acetyltransferase converts serotonin to N-acetylserotonin

Question 23

What is the second step in the conversion of serotonin to melatonin? What does that enzyme require?

Answer 23

methylation by hydroxyindole-O-methyltransferase

SAM

Question 24

What is the third product that tryptophan can be converted into?

Answer 24

niacin

Question 25

What enzyme begins the synthesis of tryptophan to niacin?

Answer 25

IDO | indolamine-2,3-dioxygenase

Question 26

What is niacin synthesized from?

Answer 26

Tryptophan

Question 27

What co-factors are required for the conversion of tryptophan to niacin?

Answer 27

iron, riboflavin and pyridoxine

Question 28

What can Hartnup disease be treated with?

Answer 28

high protein diet and niacin

Question 29

What is formed by the decarboxylation of glutamate? What co-factor does this require?

Answer 29

GABA pyridoxal phosphate

Question 30

Histamine is released by what type of cell?

Answer 30

mast cell

Question 31

What three amino acids make up glutathione?

Answer 31

glutamate cysteine glycine

Question 32

Why is glutathione such a stable molecule?

Answer 32

special peptide bond that is resistant to proteolysis

Question 33

What else is atypical about glutathione?

Answer 33

it is not manufactured by ribosomes

Question 34

How does glutathione act to scavenge free radicals?

Answer 34

absorbing electrons and forming a glutathione dimer

Question 35

Glutathione peroxidase contains what element?

Answer 35

selenium

Question 36

In RBCs, glutathione acts to do what?

Answer 36

reduce oxygen free radicals produced during oxygen transport

Question 37

What is the function of glutathione-s-transferase?

Answer 37

transfer glutathione to electrophiles

Question 38

What elements do these electrophiles need to attach to glutathione with?

Answer 38

Sulfur, oxygen or nitrogen

Question 39

What kind of bond is generated between glutathione and these electrophiles? Where is it located?

Answer 39

a thioether linkage between the compound and cysteine of glutathione

Question 40

What is creatine production proportional to?

Answer 40

individuals muscle mass

Question 41

Regarding catecholamine synthesis, what enzyme requires THBtn?

Answer 41

tyrosine hydroxylase

Question 42

PNMT uses what as a carbon group donor?

Answer 42

SAM

Question 43

What ion does tyrosinase contain?

Answer 43

copper

Question 44

The formation of niacin from tryptophan begins with what enzyme?

Answer 44

IDO

Question 45

Decarboxylation of histidine yields what? What co-factor does this reactio require?

Answer 45

Histamine Pyridoxal phosphate

Question 46

What is the first enzymatic step in the production of serotonin? What co-factor does this enzyme require?

Answer 46

hydroxylation of tryptophan to 5-hydroxytryptophan THBtn

Question 47

What are GST molecules involved in?

Answer 47

detoxification process

Question 48

What electrophiles must a compound contain to become attached to glutathione?

Answer 48

S, O, N

Question 49

In the formation of glutathione conjugates, what type of linkage is created?

Answer 49

thioether

Question 50

The overall rate of amino acid degradation is influenced by what enzyme?

Answer 50

mitochondrial glutamate dehydrogenase

Question 51

What is the activity of mitochondrial glutamate dehydrogenase dictated by? How so?

Answer 51

cellular energy charge high energy = inhibit low energy = activate

Question 52

How is B12 related to myelin?

Answer 52

cant degrade methylmalonyl-CoA w/o B12 odd chain fatty acids get incorporated into myelin = bad

Question 53

What is the fucntion of BCAT? Where is the majority of BCAT located?

Answer 53

to form branched-chain alpha-keto acids from branched chains AA's muscles

Question 54

Where are branched chain alpha keto acids degraded? What enzyme is responsible for this?

Answer 54

liver BCKDH

Question 55

MSUD features an accumulation of what products? What is this condition caused by?

Answer 55

branched chain alpha keto acids lack of BCKDH

Question 56

How does mannitol aid in the treatment of hyperammonemia?

Answer 56

diuresis

Question 57

What does phenylbutryate 'pull' out of solution?

Answer 57

glutamine

Question 58

What does benzoate 'pull' out of solution?

Answer 58

glycine

Question 59

Specifically, what brain structure can swell during hyperammonemia?

Answer 59

astrocytes

Question 60

Increased ammonia increases the synthesis of what amino acid?

Answer 60

glutamine