560C Test 2

Question 1

active vitamin C isomer

Answer 1

L isomer

Question 2

Vitamin C role in collagen

Answer 2

3 hydroxylation reactions require Vitamin C.

Question 3

Vitamin C primary role as antioxidant

Answer 3

• Reducing agent or electron donor and thereby has antioxidant activity or functions.
• Regenerates viatmin E and glutathione

Question 4

What is the Body pool of vitamin C

Answer 4

2g

Question 5

RDA of vitamin C

Answer 5

• Men 90 mg

* Women 75 mg

Question 6

UI of Vitamin C

Answer 6

2g

Question 7

Vitamin C deficiency

Answer 7

Scurvy 
symptoms
- fatigue, enlarged hair follicles, red skin discoloration, ruptured blood vessels, easy bruising 
- joint pain
- oral changes

Question 8

functions of vitamin C

Answer 8

collagen synthesis, carnitine synthesis, tyrosine synthesis and catabolism and neurotransmitter synthesis

Question 9

mineral interference with vitamin C

Answer 9

iron and copper

Question 10

vitamin C absorption rates

Answer 10

• Absorption of vitamin decreases with increased intake

o 16% is absorbed at high intakes (~12g) vs 98% at low intakes (<20 mg)

Question 11

Thaimin B?

Answer 11

B1

Question 12

Riboflavin B?

Answer 12

B2

Question 13

Niacin B?

Answer 13

B3

Question 14

Pantothenic Acid B?

Answer 14

B5

Question 15

Pyridoxine B?

Answer 15

B6

Question 16

Biotin B?

Answer 16

B7

Question 17

Folate B?

Answer 17

B9

Question 18

Cobalamin B?

Answer 18

B12

Question 19

thaimin Major function

Answer 19

• Metabolism of carbohydrates, branched chain amino acids and fatty acids – energy
o Energy transformation (coenzyme role)
o Synthesis of pentoses and NADPH: (coenzyme role)
o Membrane and nerve conduction (non coenzyme)

Question 20

Riboflavin Major function

Answer 20

o	Oxidation-reduction (redox) reactions
	metabolism of carbohydrates, lipids, and proteins. 
	Glutathione reductase
o	Metabolism of other vitamins
	Conversion of B6 to

Question 21

Niacin Major function

Answer 21

• 200 enzymes require NAD and NADP
• redox role
• NADPH, Acts as a reducing agent in many biosynthetic pathways such as fatty acid, cholesterol and steroid hormone synthesis

Question 22

Pantothenic Acid Major function

Answer 22

• Component CoA and 4’phosphopantethenine
• Acetylates nutrients including sugars and proteins among others
• Metabolism of carbs, lipids and protein
• critical to the manufacture of red blood cells, as well as sex and stress-related

Question 23

Pyridoxine Major function

Answer 23

• amino acid metabolism
• gene expression
• schiff base
• First step in synthesis of heme
• Niacin synthesis from tryptophan requires PLP

Question 24

Biotin Major function

Answer 24

• help the body to convert food (carbohydrates) into fuel (glucose), which is used to produce energy.
• metabolize fats and protein.
• biotin required for cells to progress normally

Question 25

Folate Major function

Answer 25

o	One carbon metabolism 
o	Nucleic acid metabolism 
	DNA metabolism 
•	Synthesis of DNA from precursors
•	Synthesis of methionine from homocysteine 
•	SAM
o	Amino acid metabolism

Question 26

Cobalamin major functions

Answer 26

o conversion of homocysteine into methionine,

o converts L methylmalonyl-CoA to succinyl-CoA

Question 27

Thiamin stored

Answer 27

• Human body contains about 30mg of thiamin,
o High but small concentrations in liver, skeletal muscles, heart, kidneys and brain
o Skeletal muscles are thought to contain half of body’s thiamin

Question 28

Riboflavin stored

Answer 28

o greatest amount found in liver, kidneys and heart

Question 29

Niacin stored

Answer 29

• NAD or NADP trapped in cell

Question 30

Pantothenic Acid stored

Answer 30

• Pantothenic acid is free in blood, primarily within red blood cells
• Most Pantothenic acid is used to synthesize or resynthesize CoA, found in high concentrations in the liver, adrenal gland, kidney, brain and heart

Question 31

Pyridoxine B6 stored

Answer 31

• Muscles are major storage site, 75-80%

o 40-185 mg

Question 32

Bitoin stored

Answer 32

• Biotin found in plasma is mostly free (~ 80%), unbound state with lesser amount bound to plasma proteins,
• Stored in small quantities in muscle, liver and brain

Question 33

Folate stored

Answer 33

o ½ stored in liver

Question 34

B12 stored

Answer 34

mainly in liver

• Small amounts in muscle, bone, kidneys, heart, brain and spleen