Vitamins

Question 1

Three characteristics of a vitamin?

Answer 1

1. ) Organic compound
2. ) Cannot be synthesized in sufficient amounts in the body
3. ) Essential function that in absence it causes physical symptoms that disappear with administration

Question 2

Water soluble vitamins:

Answer 2

C: ascorbic acid
B1: thiamine
B2: riboflavin
B3: niacin
B5: pantothenic acid
B6: pyridoxine
B7: biotin
B9: folate
B12: cobalamin

Question 3

Fat-soluble vitamins:

Answer 3

A: retinol
D: calcitriol
E: a, b, g-tocopherol
K: K1, K2, K3

Question 4

What are fat soluble vitamins associated with?

Answer 4

Bound to proteins and lipids in food

Question 5

What releases FS vitamins from lipids and proteins in food?

Answer 5

HCl denaturation and pepsin

Question 6

How do FS vitamins make it across plasma membrane?

Answer 6

Complexed to FA, complexed with TAGs and removed from chylomicrons by lipoprotein lipase

Question 7

What activates lipoprotein lipase to cleave TAGs?

Answer 7

Apo C2

Question 8

What is beta-carotene?

Answer 8

Vitamin A pro-drug

Question 9

How does rhodopsin change in conformation in sunlight?

Answer 9

11-cis to 11-trans

Question 10

What can vitamin A deficiency result in?

Answer 10

Night blindness

Question 11

What affect does Vitamin A have on 1st trimester and children respectively?

Answer 11

1st trimester: too much defects

Children: too little reduced growth

Question 12

What does too much retinol cause?

Answer 12

Bone resorption and osteoporosis

Question 13

What is vitamin D a product of?

Answer 13

Cholesterol

Question 14

Vitamin D deficiency causes:

Answer 14

Rickets

Osteomalacia

Question 15

What does low calcium cause?

Answer 15

Parathyroid hormone release (takes Ca2+ from bones) stimulating Vitamin D activation in kidney

Question 16

What does Vitamin D do?

Answer 16

Increased absorption of calcium and phosphate

Question 17

Vitamin D affect on immune?

Answer 17

Binds to TLRs causing expression of 1alpha-hydroxylase and synth of calcitriol inhibiting proliferation and autoimmunity; also anti-inflammatory cytokines made

Question 18

Most active form of Vitamin E?

Answer 18

Alpha-tocopherol

Question 19

What is high in vitamin E?

Answer 19

Seed oils; destroyed commercially so most are synthetic

Question 20

Vitamin E affects:

Answer 20

Antioxidant
Inhibit platelet clumping
Reduce plaque buildup

Question 21

How is excess vitamin K excreted?

Answer 21

Bile

Question 22

What clotting factors need vitamin K?

Answer 22

VII, IX, X, C and S

Cofactor for gamma-glutamyl carboxylase

Question 23

How does Coumadin work?

Answer 23

Blocks vitamin K recharging

Question 24

What happens once vitamin K is digested?

Answer 24

It gets converted by colon flora

Question 25

Why is vitamin K administered to infants at birth?

Answer 25

It doesn't cross the placenta and no gut bacteria for vitamin K production and no vitamin K in breast milk

Question 26

Two proteins dependent on vitamin K:

Answer 26

Osteocalcin: secreted by bone-forming osteoblasts | Matric Gla Protein: binds Ca2+ and assists calcium binding to bone matrix and inhibits vascular mineralization

Question 27

Effect of vitamin K on vessels?

Answer 27

Stops Ca2+ plaque buildup

Question 28

How is reduced and oxidized vitamin C absorbed respectively?

Answer 28

Oxidized: passive GLUT1/3 Reduced: active Na+-dependent transporters

Question 29

Effect of vitamin C on iron?

Answer 29

Increase absorbance

Question 30

What needs vitamin C for formation?

Answer 30

Collagen

Question 31

What does a deficiency in vitamin C cause?

Answer 31

Scurvy

Question 32

What is vitamin B1 important as?

Answer 32

A cofactor for multiple reactions

Question 33

What does vitamin B1 defect cause?

Answer 33

Wet beriberi: edema CHF | Dry beriberi: muscle wasting

Question 34

What does excess riboflavin (B2) cause?

Answer 34

Bright yellow urine

Question 35

B2 needed for:

Answer 35

Cofactor for radical and polar redox reactions

Question 36

B2 deficiency:

Answer 36

Irritated mouth, tongue, cracked lips

Question 37

When is B2 stable and not stable?

Answer 37

Stable during cooking not in UV light

Question 38

What can vitamin B3 be made from?

Answer 38

Tryptophan

Question 39

What is niacin B3 converted to?

Answer 39

NAD+ and NADP+

Question 40

What can niacin do to cholesterol?

Answer 40

Lower LDL | Elevate HDL

Question 41

Excess niacin:

Answer 41

Reddish skin

Question 42

Deficiency in niacin (3 D's)

Answer 42

Pellagra: dermatitis, dementia, diarrhea

Question 43

B6 found in foods?

Answer 43

Pyridoxine

Question 44

Active form of B6?

Answer 44

PLP

Question 45

Excess B6:

Answer 45

Nerve damage

Question 46

Deficiency in B6:

Answer 46

Microcytic hypochromic anemia (small and pale RBC's)

Question 47

What is hydroxycobalamin (activated charcoal) used to treat (B12)?

Answer 47

Cyanide poisoning

Question 48

How does hydroxycobalamin treat CN- poisoning?

Answer 48

Take CN- into the molecule taking OH- place

Question 49

How is methylcobalamin absorbed?

Answer 49

Haptocorrin (R factor) binds to B12 protecting it from stomach acid; IF binds and allows absorption

Question 50

What is biotin (B7) used for?

Answer 50

Carboxylase enzyme reactions (addition of CO2)

Question 51

What is pantothenic acid (B5) used for?

Answer 51

Essential part of CoA needed in catabolic and anabolic reactions

Question 52

Where is CoQ10 found?

Answer 52

ETC Complex I

Question 53

What is CoQ10 a step of?

Answer 53

Downstream of cholesterol synthesis