Vitamins and Minerals

Question 1

This disease is a result of dietary deficiency of Vitamin C required by prolyl and lysyl hydroxylases.

Symptoms include bleeding gums, swelling joints, poor wound healing and death.

Answer 1

Scurvy

Question 2

This disease is characterized by kinky hair and growth retardation. It is due to dietary deficiency in copper required by ___(enzyme) in cross-linking that strengthens ____ (protein).

Answer 2

Menke’s disease

Copper required by lysyl oxidase, which cross links collagen.

Question 3

Enzymes requiring copper

Answer 3

Losers Don’t Take Copper

Lysyl oxidase
Dopamine-b-hydroxylase
Tyrosinase
Cytochrome c oxidase

Question 4

Deficiency in which vitamin may occur in carcinoid syndrome

Answer 4

Niacin.

Shunting of niacin to serotonin synthesis

Question 5

Deficiency in this mineral along with infection with a virulent strain of Coxsackie virus causes cardiomyopathy

Answer 5

Selenium

Disease is called Keshan disease

Question 6

Deficiency in this vitamin causes spinocerebellar degeneration

Answer 6

Vitamin E

Question 7

Which vitamin is used as a co-enzyme in:
A. Carboxylation reactions
B. Decarboxylation reactions

Answer 7

A. Biotin

B. Thiamine

Question 8

Glutathione peroxidase is an enzyme that contains ___ at the active site

Answer 8

Selenocyteine (selenium analogue of cysteine)

Question 9

This mineral is a component of enzymes, principally oxidases

Answer 9

Zinc

Question 10

Excessive intake of this mineral can interfere with thyroid hormone synthesis

Answer 10

Calcium

Question 11

This mineral is a catalyst in hemoglobin formation; essential in production of RBC and required for absorption of Fe

Answer 11

Copper

Question 12

This mineral is a constituent of enzymes in CO2 exchange and CHON hydrolysis

Answer 12

Zinc

Question 13

This vitamin is essential in the non-oxidative phase of pentose phosphate pathway. It is a co-factor for which enzymes.

Answer 13

Thiamine.

Transketolase

Question 14

This vitamin is part of the fatty acid synthase enzyme complex.

Answer 14

Pantothenic acid

Question 15

Severe burning and aching of the feet, hyperesthesia, and vasomotor changes of the feet that leads to excessive sweating. This syndrome is due to deficiency in ___

Answer 15

Pantothenic acid

Question 16

This vitamin enhances absorption of iron

Answer 16

Vitamin C

Question 17

The earliest sign of Vitamin A deficiency

Answer 17

Loss of sensitivity to green light
> Impairment of ability to adapt to dim light
> Night blindness

Question 18

What is the relationship of Vitamin A with infection?

Answer 18

Vitamin A has a role in differentiation of immune cells; deficiency increases susceptibility to infections.

Retinol binding protein is also a negative acute phase protein; lowering vitamin concentration in infection

Question 19

Calcitriol is able to reduce its concentration by inducing ___ (enzyme) and inhibiting ____.

Answer 19

Inducing 24-hydroxylase

Inhibiting 1-hydroxylase

Question 20

Most active of the Vitamin E compounds

Answer 20

D-a-tocopherol

Question 21

Vitamin K Quiz

1. Synthesized by intestinal bacteria
2. Synthetic compounds
3. Normal dietary source

Answer 21

1. Menaquinones
2. Menadione, menadiol
3. Phylloquinone

Question 22

Thiamine is a coenzyme of which enzymes

Answer 22

Pyruvate dehydrogenase
a-ketoglutarate dehydrogenase
Branched chain keto-acid dehydrogenase
Transketolase

Question 23

This vitamin phosphorylates and activates a chloride channel in the nerve membrane

Answer 23

Thiamine

Question 24

Accepted index of:

1. Thiamine nutritional status?
2. Riboflavin status?
3. Pyridoxine status?

Answer 24

B1:
Activation of apo-transketolase in erythrocyte lysate by thiamine diphosphate.

B2:
Activation of erythrocyte glutathione reductase by FAD added in vitro

B6:
Activation of erythrocyte transaminases

Question 25

Because of its yellow color, it is widely used as an additive

Answer 25

Riboflavin

Question 26

What is the formula for the niacin content of foods?

Answer 26

mg niacin equivalents = mg preformed niacin + 1/60 (mg tryptophan)

Question 27

The source of ADP ribose for ADP ribosylation of proteins and polyADP-ribosylation of nucleoproteins involved in DNA repair.

Answer 27

NAD

Question 28

Carcinoid syndrome is characterized by a relative deficiency in this vitamin.

Answer 28

High synthesis of 5-hydroxytryptamine accounts for 60% of body's tryptophan metabolism; diverting the amino acid from NAD synthesis.

Question 29

Pellagra is more common in women. Why?

Answer 29

Estrogen metabolites inhibit tryptophan.

Question 30

Consequences of excessive niacin

Answer 30

Dilation of blood vessels and flushing Skin irritation Liver damage (>500 mg/day)

Question 31

Most of the Vitamin B6 in the body is in ____.

Answer 31

Pyridoxal phosphate in muscle, associated with glycogen phosphorylase (80%)

Question 32

This vitamin is the co-factor of glycogen phosphorylase.

Answer 32

B6 (Pyridoxal phosphate)

Question 33

This vitamin is a co-factor in transamination and decarboxylation of amino acids

Answer 33

B6

Question 34

In deficiency of this vitamin, there is increased sensitivity to the actions of estrogens, androgens, cortisol, and vitamin D.

Answer 34

B6. B6 terminates hormone action by removing hormone-receptor complex from DNA binding.

Question 35

Excess of this vitamin is associated with sensory neuropathy

Answer 35

Vitamin B6 (2-7 g/day)

Question 36

There is some evidence that this vitamin is effective in treating premenstrual syndrome.

Answer 36

Vitamin B6

Question 37

There are no plant sources of this vitamin, making vegans at risk of developing deficiency.

Answer 37

Vitamin B12

Question 38

Describe the absorption of folate?

Answer 38

1. Bound to protein in food 2. In the stomach, it is released from protein by gastric acid and protein and binds to cobalophilin secreted in saliva. 3. In the duodenum, cobalophilin is hydrolyzed; and vitamin binds to IF. 4. IF-vitamin complex absorbed in the ileum.

Question 39

What are the three enzymes dependent on Vitamin B12?

Answer 39

``` 1. Methylmalonyl mutase (Methylmalonyl CoA > Succinyl CoA) 2. Methionine synthase (Homocysteine > Methionine converting Methyl- to tetrahydrofolate) 3. Leucine aminomutase ```

Question 40

Synthetic folic acid

Answer 40

Leucovorin

Question 41

How does vitamin B12 deficiency lead to folate deficiency?

Answer 41

Methionine synthase is Vitamin B12 dependent. This enzyme converts methyl-tetrahydrofolate to the active tetrahydrofolate while converting homocysteine to methionine. With Vitamin B12 deficiency, folate is stuck in inactive 'methyltetrahydrofolate' form.

Question 42

Elevated __ which occurs due to folate deficiency leads to increased risk of atherosclerosis, thrombosis and hypertension.

Answer 42

Homocysteine

Question 43

A number of studies suggest that folate supplementation can reduce risk of some cancers. How?

Answer 43

Low folate results in impaired methylation of CpG islands in DNA, which is associated with increased risk of colorectal and other CAs.

Question 44

Biotin-dependent enzymes

Answer 44

1. AcetylCoA carboxylase Acetyl CoA > malonyl Coa 2.

Question 45

Vitamin C is the coenzyme for 2 hydroxylases.

Answer 45

1. Dopamine b-hydroxylase | 2. Peptidylglycine hydroxylase

Question 46

This vitamin is a cofactor of ALA synthase. Used as treatment in sideroblastic anemia.

Answer 46

Pyridoxine