Biochem

Question 1

Hartnup Disease

Answer 1

Absence of AA transporter –> loss of tryptophan in urine

Symptoms of niacin deficiency: pellagra (hyperpigmentation on sun-exposed skin) and neurological symptoms

Question 2

Branched-chain AAs

Answer 2

Valine, Leucine, Isoleucine

Question 3

Maple syrup urine disease

Answer 3

Deficient alpha ketoacid dehydrogenase

Leads to sweet smelling urine and neurotoxicity

Question 4

Peroxisomes

Answer 4

Oxidate very long and branched chain fatty acids

Question 5

Proteasomes

Answer 5

Degradation of ubiquitinated proteins

Question 6

Rate limiting step in fatty acid synthesis

Answer 6

Acetyl-CoA –> Malonyl-CoA
Enzyme: Acetyl-CoA carboxylase
Requires: CO2 and Biotin (B7)

Question 7

Biotin

Answer 7

Vit B7

Important for carboxylation enzymes

Question 8

Enzyme that pulls triglycerides out of adipose tissue to release fatty acids from glycerol backbone

Answer 8

Hormone Sensitive Lipase

Responds to glucagon

Question 9

Carnitine shuttle

Answer 9

Moves fatty acyl CoA –> mitochondria matrix

Binds with carnitine (CPT1) –> acyl carnitine (moves to matrix) –> converted back to fatty acyl CoA (CPT2)

Question 10

Hypoketotic Hypoglycemia

Answer 10

Due to carnitine deficiency

Will have low acylcarnitine

Question 11

MCAD deficiency 
(Medium Chain Fatty Acetyl-CoA Dehydrogenase)

Answer 11

Hypoglycemia without ketones

High acycarnitine levels

Question 12

Most common urea cycle disorder

Answer 12

Ornithine transcarbamylase deficiency

Increased carbamoyl phosphate, orotic acid, and ammonia

Question 13

Vit B1 other name

Associated enzymes

Associated disorders

Answer 13

Thiamine

Cofactor for dehydrogenase enzymes and transketolase

Beriberi (neuritis, tachycardia, edema), Wernicke-Korsakoff

Question 14

Vit B2 other name

Purpose

Answer 14

Riboflavin

Generate FAD and FADH2

Question 15

Vit B3 other name

Purpose

Associated disorders

Answer 15

Niacin (Can also be synthesized from tryptophan B6)

Produce NAD and NADH

Pellagra (dermatitis, diarrhea, dementia, death)
Carcinoid syndrome, Hartnup disease

Question 16

Vit B6 other name

Purpose

Associated disorders

Answer 16

Pyridoxal phosphate

Aminotransferase reactions, neurotransmitters, synthesize niacin and ALA (heme)

Sideroblastic anemia, isoniazid use, CNS + pellagra

Question 17

Vit B7 other name

Associated enzymes

Associated disorders

Answer 17

Biotin

Carboxylase enzymes

Deficient with ingestion of raw egg whites

Question 18

Vit B9 and B12 other names

Purpose

Associated disorders

Answer 18

Folate and cobalamin

Thymidine and methionine synthesis (B12 odd chain fatty acid metabolism)

Megaloblastic anemia

Question 19

Vit A other name

Functions

Deficiency symptoms

Answer 19

Retinol

Important for eyes and skin

Night blindness, dry skin, growth failure

Question 20

What is used to convert Fe3+ iron –> Fe2+ iorn

Answer 20

Vit C (Ascorbic acid)

Question 21

Phenylalanine –> tyrosine requires

Answer 21

BH4
Dihyropterine reductase
NADH

Question 22

PKU

Answer 22

Deficiency of phenylalanine hydroxylase or BH4 (will also have dopamine and serotonin issues)
Musty smell in urine, CNS symptoms, and pale skin/eyes

Question 23

Babies with high alanine

Answer 23

Mitochondrial disorders

Question 24

Ornithine transcarbamylase deficiency

Answer 24

Hyperammonemia
High carbamoyl phosphate
High orotic acid

Question 25

Apo B48

Answer 25

Chylomicrons

Required for secretion from enterocytes

Question 26

Apo C-II

Answer 26

Cofactor for LPL

Question 27

Apo E

Answer 27

Allows for the uptake of remnants

Question 28

B-100

Answer 28

Allows uptake of cholesterol through LDL