Biochemistry - Nutrition and Metabolism 1

Question 1

Vitamin A usage

Answer 1

promyelocytic leukemia

Acne

Measles “MAP”

Question 2

thiamine function

Answer 2

Be APT In thiamine pyrophosphate (TPP), a cofactor for several dehydrogenase enzyme reactions:

• Branched-chain ketoacid dehydrogenase
• Alfa -ketoglutarate dehydrogenase (TCA cycle)
• Pyruvate dehydrogenase (links glycolysis to TCA cycle)
• Transketolase (HMP shunt)

Question 3

B3 excess

Answer 3

Facial flushing (induced by prostaglandin, not histamine; can avoid by taking aspirin with niacin)

hyperglycemia

hyperuricemia

“Podagra=prostaglandin”

Question 4

B5 function

Answer 4

An essential component of coenzyme A (CoA, a cofactor for acyl transfers) and fatty acid synthase.

CoA for FA synthesis

Question 5

B6 function

Answer 5

cofactor used in:

transamination (eg, ALT and AST)

decarboxylation reactions

glycogen phosphorylase.

Synthesis of: cystathionine, heme, niacin, histamine, and neurotransmitters including serotonin, epinephrine, norepinephrine (NE), dopamine, and GABA (SEND G).

CNN-HH (CNN on the hours)

Question 6

Vit C function

Answer 6

Antioxidant

Iron aBsorption

Collagen synthesis

Dopamine beta-hydroxylase

Question 7

Vit C excess

Answer 7

Iron overload

Ca-oxalate stones

Question 8

Vit D at higher levels…

Answer 8

bone resorption at higher levels.

Question 9

give Vit D to______

Answer 9

Give oral vitamin D and K to breastfed infants. (give DicK)

Deficiency is exacerbated by pigmented skin, premature birth, breastfed.

Question 10

Vit E excess

Answer 10

Risk of enterocolitis in infants.

High-dose supplementation may alter the metabolism of vitamin K - enhanced anticoagulant effects of warfarin.

Question 11

Zinc deficiency

Answer 11

Taste,

smell

dec. adult hair

hypogonadism

immunity

wound healing

Associated with acrodermatitis enteropathica (defect in intestinal zinc absorption).

May predispose to alcoholic cirrhosis.

Question 12

Ethanol metabolism inc NADH/ NAD+ ratio in the liver, causing:

Answer 12

FLOK:

F - Fatty liver (DHAP -> glycerol-3P, acetyl CoA -> FA, Both combine to make TG)

L - Lactic acidosis (pyruvate to lactate)

O - OAA -> malate (fasting hypoglycemia)

K - Ketoacidosis (acetyl Coa to ketone bodies)

Question 13

ATP production in heart and liver

Answer 13

32 net ATP via malate-aspartate shuttle

Question 14

ATP production in muscle

Answer 14

30 net ATP via glycerol-3-phosphate shuttle

Question 15

NADPH is used in:

Answer 15

• Glutathione reductase
• Cytochrome P-450 system
• Anabolic processes
• Respiratory burst

“Powers the G-CAR”

Question 16

anaerobic glycolysis - major pathway in…

Answer 16

C - cornea

a

T - testes

W - WBCs

a

L - lens

K - kidney medulla

e

R - RBCs

Question 17

Electron transport inhibitors: complex one inhibitor

Answer 17

Rotenone

Question 18

Electron transport inhibitors: complex 3

Answer 18

“An-3-mycin” (antimycin) A

Question 19

Electron transport inhibitors: complex 4

Answer 19

Cyanide, carbon monoxide, azide (the -ides, 4 letters) inhibit complex IV.

Question 20

ATP synthase inhibitors

Answer 20

Oligomycin.

Question 21

Uncoupling agents

Answer 21

2,4-Dinitrophenol (used illicitly for weight loss)

aspirin (fevers often occur after the overdose)

thermogenin in brown fat (has more mitochondria than white fat).

Question 22

Pyruvate carboxylase

Answer 22

Requires biotin, ATP.

Activated by acetyl-CoA

Question 23

Phosphoenolpyruvate carboxykinase - Requires_____

Answer 23

Requires GTP.

Question 24

Glucose-6- phosphatase location

Answer 24

In ER.

glucose-6-phosphate -> glucose.

Question 25

Pentose phosphate pathway sites:

Answer 25

Sites of fatty acid or steroid synthesis - “the RALM”

R - RBCs

A - adrenal cortex

L - liver

M - mammary glands (lactating)

Question 26

Pentose phosphate pathway Oxidative (irreversible) products:

Answer 26

(G6PD)

Products:

Ribulose-5-P

CO2

2 NADPH

Question 27

Pentose phosphate pathway Nonoxidative (reversible)

Answer 27

(Phosphopentose isomerase and transketolases)

Products:

Ribose-5-P

glyceraldehyde-3-P

Fructose-6-P

Question 28

Glucose-6-phosphate dehydrogenase deficiency leads to poor defense against oxidizing agents like…

Answer 28

F - fava beans

e

M - malaria Tx (primaquine/ chloroquine)

e

N - nitrofurantoin

I - Infection (most common cause)

S - sulfonamides

T - tuberculosis drugs

Question 29

Dihydroxyacetone-P and Glyceraldehyde to Glyceraldehyde-3-P

Answer 29

Dihydroxyacetone-P: Triose phosphate isomerase

Glyceraldehyde: Triose kinase

Question 30

Galactokinase deficiency Sx

Answer 30

galactose appears in the blood (galactosemia) and urine (galactosuria);

infantile cataracts.

May present as failure to track objects or to develop a social smile.

Question 31

Classic galactosemia SX

Answer 31

failure to thrive

jaundice

hepatomegaly

infantile cataracts

intellectual disability

Can predispose to E coli sepsis in neonates.

Question 32

Tissues with Aldose reductase and Sorbitol dehydrogenase

Answer 32

Liver, Ovaries, and Seminal vesicles have both enzymes

(they LOSe sorbitol).

Question 33

Tissues with Aldose reductase only

Answer 33

L - Lens has primarily aldose reductase.

u

R - Retina

K - Kidneys

S - Schwann cells

Have only aldose reductase (LuRKS).

Question 34

Urea cycle

Answer 34

ornithine can create and assemble Fn A Urea!