Biochem p. 104-108

Question 1

AAs required during periods of

growth?

Answer 1

Arg and His “HAl is tall”

Question 2

AAs that are in histones, which bind negatively charged DNA?

Answer 2

Arg and Lys

Question 3

Excess —— is generated by urea cycle and

converted to urea and excreted by the kidneys.

Answer 3

nitrogen (NH3)

Question 4

which enzyme is used to produce Carbamoyl

phosphate?

Answer 4

Carbamoyl phosphate synthetase I (mitochindria) 
CPs II (cytoplasm)

Question 5

What is the required co-factor of Carbamoyl phosphate synthetase I?

Answer 5

N-acetylglutamate “NAG”

Question 6

where does urea cycle occur?

Answer 6

mitochondria, cytoplasm

Question 7

Using what enzyme and which substrate does carbamoyl phosphate become Citruline?

Answer 7

Ornithine transcarbamylase

Ornathine + Carbamoyl phosphate

Question 8

which AAs is added into the Urea cycle?

Answer 8

Aspartate

Question 9

Transport of ammonia by alanine and glutamate happens in which 2 cell types?

Answer 9

Muscle

Liver

Question 10

Absence of N-acetylglutamate cause what path?

Answer 10

hyperammonemia.

Question 11

Neonates that has poorly regulated respiration and body temperature, poor feeding, developmental delay and intellectual disability is seen in which 2 pathologies?

Answer 11

Carbamoyl phosphate synthetase I deficiency and N-acetylglutamate synth def both cause Hyperammonia.

Question 12

T or F? The most common urea cycle disorder is a autosomal recessive disorder.

Answer 12

F! OTC is X-linked recessive

Question 13

3 Finding in Ornithine transcarbamylase deficiency?

Answer 13

Orotic acid in blood and urine
decr BUN
symptoms of hyperammonemia

Question 14

Excess of —– is converted to orotic acid which is part of the —– synthesis pathway.

Answer 14

carbamoyl phosphate, pyrimidine

Question 15

Hypothyroid pts might be deficient in which AA?

Answer 15

Phenylalanine –> tyroxine

Question 16

Pts having trouble with sleep might be deficient in what AA?

Answer 16

Tryptophan –> melatonin

Question 17

Pts with porphyrias might have what AA def.?

Answer 17

Glycine –> Heme

Question 18

G6PD dz might occur due to what AA def?

Answer 18

Glutamate –> Glutathion

Question 19

Def of what AA can dec BUN and creatine?

Answer 19

Argenine

Question 20

Male pt with angina and ED might have what AA deficiency?

Answer 20

Argenine… no NO production in the vessles

Question 21

Pt suffering from albinism might be def in what AA?

Answer 21

Phenylalanine –> melanine

Question 22

Pt with Parkinson disease might be def in which 2 AA?

Answer 22

Phenylalanine and Tyrosine –> dopamin

Question 23

Which AA is constantly converted to its 2nd end product in Locus ceruleus in a pt with anxiety?

Answer 23

Phenylalanine–> NE–>EPi

Question 24

In theory, if one is trying to increase his/her HDL levels, which AA and its cofactor are needed?

Answer 24

Tryptophan –> niacin using Vit B2 and vit B6

Question 25

Severe vit B6 deficiency can theoretically worsen which 2 neurological disorders?

Answer 25

anxiety Huntington disease decr GABA

Question 26

Which cofactors are needed to produce a neurotransmitter which is decr in anxiety and depression

Answer 26

Vit B6, BH4 used to make serotonin from tryptophan

Question 27

AA used to produce neurotransmitter produced in Nucleus accumbens?

Answer 27

Glutamate makes GABA

Question 28

Which AA is in excess and which is essential in PKU?

Answer 28

excess: phenylalanine essential: tyrosine

Question 29

Def of tetrahydrobiopterin cofactor is see in which path?

Answer 29

malignant PKU

Question 30

Ž Musty body odor is usually seen in

Answer 30

Disorder of aromatic amino acid metabolism

Question 31

which artificial sweetener must PKU pts avoid?

Answer 31

aspartame, which contains phenylalanine.

Question 32

(4) Finding is maternal PKU?

Answer 32

microcephaly intellectual disability growth retardation congenital heart defects

Question 33

Findings of dark connective tissue, brown pigmented sclerae, urine turns black on prolonged exposure to air are seen in a pathology that has an enzyme def in degradation which AA?

Answer 33

Tyrosine, in Alkaptonurea

Question 34

Homogentisic acid is toxic to what type of collagen that causes debilitating arthralgias?

Answer 34

type ii for Cartilage

Question 35

Enzyme def in Alkaptonurea?

Answer 35

Homogentisate oxidase

Question 36

Enzyme deficiency in Maple Syrup dz (MSD)?

Answer 36

 α-ketoacid dehydrogenase

Question 37

Degradation of which branched amino | acids are blocked MSD? which one the most?

Answer 37

Isoleucine, Leucine, Valine--- Leucine most

Question 38

What should be supplemented in MSD?

Answer 38

thiamine supplementation (vit B1)

Question 39

Which dz has this finding: intellectual disability, osteoporosis, marfanoid habitus, kyphosis, lens subluxation, thrombosis, and atherosclerosis (stroke and MI).

Answer 39

Homocystinuria

Question 40

What other dz do we find lens subluxation besides homocystinurea and how do we differentiate btw them?

Answer 40

Homocystinurea --- downward and in | Marfan synd --- upward and out

Question 41

Name the 2 different enzyme deficiencies that can cause homocystinurea?

Answer 41

Homocysteine methyltransferase | Cystathionine synthase

Question 42

What is another cause of homocystinurea?

Answer 42

decr affinity of cystathionine synthase for pyridoxal phosphate/vit B6. Tx:  B6 and cysteine in diet

Question 43

Which type of the homocystinureas can be treated with incr  B12 and folate in diet?

Answer 43

the one with Cystathionine synthase defi

Question 44

Cystinuria is a hereditary defect of renal --- and intestinal AA transporter that prevents reabsorption of:

Answer 44

PCT | Cysteine, Ornithine, Lysine, and Arginine (COLA).

Question 45

How is Cystinuria diagnosed?

Answer 45

via Urinary cyanide-nitroprusside test

Question 46

Tx of cystine stones?

Answer 46

``` urinary alkalinization (e.g., potassium citrate, acetazolamide) chelating agents (e.g., penicillamine) ```

Question 47

Pt with intellectual disability, growth | retardation, seizures, fair skin, eczema, musty body odor is missing either an enzyme or a cofactor? what are thos?

Answer 47

phenylalanine hydroxylase or tetrahydrobiopterin cofactor

Question 48

(7) findings in Homocystinurea:

Answer 48

``` intellectual disability osteoporosis kyphosis marfanoid habitus lens subluxation thrombosis atherosclerosis (stroke and MI). ```

Question 49

Methionine synthase is seen in what dz? what another name for this enzyme?

Answer 49

Homocystinurea | homocysteine methyltransferase

Question 50

How can strict vegans get an MI or stroke?

Answer 50

Vit B12 deficiency can cause Homocysteine to built up and cause atherosclerosis => MI or stroke.

Question 51

Describe what Homocysteine converts into via which 2 enzymes:

Answer 51

Methionine Cystathionine --**--> Cysteine * methionine synthase, vit B12 * * cystathionine synthase, Vit 6, Serine