Final exam lecture 2

Question 1

vitamin A names and biochemical roles

Answer 1

Retinol, retinal and retinoic acid. It is stored as retinol. Retinoic acid functions as steroid hormone. It regulates cell growth and differentiation. They are also effective antioxidants.

Question 2

vit A deficiency causes, food source?

Answer 2

night blindness, (not enough active rhodopsin)
dark green and yellow vegetables, liver, egg yolk, whole milk.

Question 3

how prevalent is deficiency?

Answer 3

Deficiency is rare, but 40-60% of americans consume less than 2/3 of the RDA

Question 4

vitamin A is stored in liver as

Answer 4

retinol palmitate

Question 5

Vitamin D functions as a _______

Answer 5

steroid hormone

Question 6

Vitamin D maintains______

Answer 6

calcium homeostasis

Question 7

what causes vit D deficiency, what disease results from deficiency

Answer 7

insufficient exposure to sunlight, rickets in young children and osteomalacia in adults

Question 8

dietary sources of vit D

Answer 8

Vitamin D, milk, fish, liver, egg yolk

Question 9

biochemical role of vitamin E

Answer 9

acts as an antioxidant, protecting unsaturated fatty acids.

Question 10

Vit E occurs in diet as

Answer 10

tocopherols and tocotrienols

Question 11

how does vitamin E reduce the risk of CV disease

Answer 11

prevents oxidation of LDL, oxidized form of LDL increases CVS risk

Question 12

vitamin E dietary sources

Answer 12

Vegetable oils rich in polyunsaturated fatty acids

Question 13

biochemical role of vitamin K

Answer 13

Essential for blood clotting and bone mineralization

Question 14

why is vitamin K essential for blood clotting and bone mineralization

Answer 14

Several proteins in coagulation and bone mineralization require gamma-carboxyglutamic acid. Vit K is required for modification of glutamic acid to carboxyglutamic acid

Question 15

dietary sources of vit K

Answer 15

K1 green vegetables
K2 intestinal bacteria

Question 16

Explain the pharmacologic mechanism of warfarin

Answer 16

It is a vitamin K antagonist. It prevents thrombosis by inhibiting vit K epoxide reductase

Question 17

can water soluble vitamins be stored in the body? why?

Answer 17

No. This is because of the high water content of the body. We need a constant supply.

Question 18

biochemical use of thiamin (B1)

Answer 18

Thiamin (B1) is rapidly converted to thiamin pyrophosphate and thiamin tri-phosphate in the body.
Thiamin pyro[hos[hate functions as a co-factor in enzymatic catalysis
Thiamin triphosphate- is not a cofactor, it functions in nerve impulse in peripheral nerve membrane

Question 19

B1 deficiency name and symptoms

Answer 19

Beriberi, chaacterized by muscular atrophy and weakness.

Question 20

which populations are at risk for thiamin B1 deficiency

Answer 20

populations relying on polished rice for food or in alcoholics

Question 21

Riboflavin (b2) biochemical roles

Answer 21

precursor of cofactors used in redox reactions (FAD and FMN)

Question 22

riboflavin deficiency symptoms

Answer 22

Angular chelitis, glossitis and scaly dermatitis

Question 23

Food sources for riboflavin

Answer 23

Milk, meat, eggs, cereal

Question 24

who is at risk for B2 deficiency (riboflavin)

Answer 24

alcoholics

Question 25

biochemical role of Niacin (B3)

Answer 25

Make NAD and NADP. essential for many redox reactions
NAD is also used for ADP-ribosylation

Question 26

Severe niacin (b3) deficiency causes

Answer 26

pellagra
(dermatitis, diarrhea and dementia)

Question 27

who is at risk for Niacin (B3) deficiencies

Answer 27

Alcoholics, patients with severe malabsorption and elderly patients with restricted diet

Question 28

foods rich in Niacin (B3)

Answer 28

Meats, peanuts, cereals

Question 29

Pyridoxine (B6) biochemical use

Answer 29

transamination rxn in aa metabolism
synthesis of neurotransmitters
sphingolipid synthesis

Question 30

pyridoxine (B6) deficiency symptoms

Answer 30

mild- Irritability, nervousness and depression
Severe- peripheral neuropathy and convulsions

Question 31

food sources for pyridoxine (B6)

Answer 31

meat, vegetables and cereals

Question 32

Biotin (b7) biochemical role

Answer 32

serves as cofactor for activation of co2 in carboxylase enzymes

Question 33

who is at risk for Biotin (B7) deficiency

Answer 33

pregnant women and raw egg drinkers

Question 34

Folic acid (B9) biochemical function

Answer 34

It is essential for DNA synthesis and cellular proliferation.

Question 35

What does deficiency in folic acid (B9) do

Answer 35

Deficiency inhibits DNA synthesis, increases risk of birth defects

Question 36

Who is at risk for folic acid deficiency

Answer 36

Alcoholics

Question 37

which two enzymes use this cobalamine (B12)

Answer 37

methionine synthase and methylmalonyl- CoA mutase.

Question 38

symptoms of cobalamine deficiency

Answer 38

Anemia and neurological damage

Question 39

WHo is at risk for cobalamine deficiency

Answer 39

Long term vegetarians and patients with severe malabsorption disease

Question 40

biochemical use of ascorbic acid

Answer 40

1. functions as a cofactor for several oxidases
   required for hydroxylation of lysine and proline side chains, which is needed for collagen stability
   maintenance of normal connective tissue.
2. non-enzymatic reducing agent

Question 41

deficiency of vit C symptoms

Answer 41

Capillary fragility (easy bruising, decreased immunocompetence)
scurvy (severe)
(causes wound healing, osteoporosis, hemorrhaging, anemia)

Question 42

Calcium biochemical use

Answer 42

Most abundant mineral in body (bones, 2nd messenger, enzymes, muscle and bone)

Question 43

deficiency of Ca symptoms

Answer 43

Net loss of Ca from bones

Question 44

symptom of ca deficiency

Answer 44

osteoporosis
muscle cramps

Question 45

dietary soruces of ca

Answer 45

Dairy products, nuts, seaweeds

Question 46

Iron biochemical role

Answer 46

Component of heme, required for O2 for transport

Question 47

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