Biochem - Water Soluble Vitamins Flashcards Preview

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Flashcards in Biochem - Water Soluble Vitamins Deck (47):
1

What are the main differences between vitamins and carbs/fats/proteins? Similarities?

Vitamins:
Individual units
Not linked together
No energy yielded
Measured in micrograms or mg rather than g

Both:
Essential
Organic
available from foods

2

What are precursors or provitamins?

Inactive forms of vitamins

Converted to active form in the body
-ex: beta carotene to vitamin A

3

What do B vitamins do?

Help the body use macronutrients for fuel

4

Coenzymes of B vitamins
Energy release
AA metabolism
Help cells to multiply

Energy release:
Thiamin
Riboflavin
Niacin
Pantothenic acid
Biotin

AA metabolism:
B6

Help cells to multiply:
Folate
B12

5

Thiamin is a part of which coenzyme?

Thiamin pyrophosphate
TPP

6

Thiamine Pyrophosphate (TPP) helps in 2 processes:

1. Conversion of pyruvate to acetyl CoA
- removes C

2. TCA cycle

7

True or false: nerve and muscle activity depend on Thiamin.

True

8

Beriberi

Dry- nervous system
Muscle weakness

Wet- cardiovascular system
Dilated blood vessels, heart works harder
Kidneys retain salt and water = edema

9

Wernicke-Korsakoff Syndrome (WKS)
Symptoms

Mental confusion
Ataxia
Ophthalmoplegia

10

Toxic levels of Thiamin? Upper limit?

No adverse effects
No UL

11

Riboflavin sources

Milk
Whole grain
Dark green vegetables

12

What are FMN and FAD?

Coenzyme forms of Riboflavin

Flavin mononucleotide
Flavin adenine dinucleotide

13

Deficiencies in riboflavin cause:

Inflammation of membranes
- mouth
- skin
- eyes
- GI tract

Ariboflavinosis
- sore throat
- cracks/redness at corner of mouth
- painful, smooth, purplish red tongue

14

Riboflavin is destroyed by

UV light
Irradiation

So it is not stored in clear glass bottles

15

Niacin chemical structures

Nicotinic acid

Nicotinamide (niacinamide)
- major form found in blood

16

Coenzyme forms of Niacin

NAD

NADP

17

Niacin can be synthesized in the body, true or false?

True

60mg of tryptophan will make 1 mg of niacin

18

Deficiency of Niacin

Pellagra

The four Ds

Diarrhea
Dermatitis
Dementia
Death

19

How to estimate niacin equivalents

1 mg of niacin and 60 mg of Trp
Provides
2 mg of niacin or 2NE


We assume dietary protein is 1% Trp

20

Niacin toxicity

Dilated capillaries
Painful tingling sensation

21

Biotin carries activated __

CO2

*critical for TCA cycle
*gluconeogenesis
*fatty acid synthesis
*breakdown of fatty acids and AAs

22

Deficiencies in Biotin symptoms

Not common because it is widespread in food and GI tract bacteria can make SOME biotin

Skin rash
Hair loss
Neurological impairment

23

Raw egg whites contain a protein called ___ that interferes with ___

Avidin

Biotin absorption
Because it binds biotin

24

Possible benefits of nicotinic acid in large doses

Lower LDL cholesterol and triglycerides
Raise HDL

25

Pantothenic acid
Part of?
Found in?

Part of coenzyme A

Widespread in food
-beef, poultry, whole grains, potatoes, tomatoes, broccoli



26

How can pantothenic acid be destroyed?
Deficiencies?

Freezing, canning, refining processes


Burning feet syndrome of WWII prisoners in Asia
-usually females, at night

27

Forms of Vitamin B6

1. Pyridoxal
2. Pyridoxine
3. Pyridoxamine

All 3 concerts coenzyme to pyridoxal phosphate (PLP)

28

Where is B6 found and stored?

Exclusively in muscle tissue

Food sources:
Meats
Fish
Poultry
Potatoes
Vegetables
Fruit

29

B6 deficiency (other symptoms)

Increased risk of some cancers and cardiovascular diseases

Depression
Confusion
Convulsions
Abnormal brain wave patterns

30

B6 toxicity

Neurological damage in >2 grams daily for 2 months or more

31

Folate is also known as ?

Coenzyme form?

Folacin

Folic acid

Chemical name : PGA - pteroylglutamic acid

Coenzyme form is THF - tetrahydrofolate and DHF - dihydrofolate

32

Which coenzyme of vitamin B do you need more of during pregnancy?

Folate

33

Folate deficiency

Neural tube defects
Congenital birth defects
anemia

34

Which two coenzymes of vitamin B activate each other?

Folate and B12

*synthesis of DNA and RNA

35

Which coenzyme of vitamin B contains cobalt?

B12

36

Dietary folate equivalents

Multiple micrograms consumed by 1.7

37

Sources of B12

Animal products
-fish
-milk

38

Choline is manufactured from __ in the body

Methionine

NOT a vitamin

39

Common sources of choline

*essential nutrient

Milk
Eggs
Peanuts
Part of lecithin

40

Choline deficiencies symptoms

Body odor
Sweating
Salivation
Reduced growth rate
Low BP
Liver damage

41

Which vitamins are water soluble?

B complex
C

42

Vitamin C - antioxidant properties

Defends against free radicals
Protects tissue from oxidative stress
Enhances iron absorption

43

Active forms of Vitamin C

Ascorbic acid
Dehydroascorbic acid

44

Vitamin C is a cofactor in ___

Collagen formation

Hydroxylation of carnitine

Making hormones

Conversion of:
Trp to serotonin
Tyr to norepinephrine

45

Other roles of vitamin C

Prevention and treatment of the common cold

46

Stress (increases/decreases) vitamin C needs. What else does this?

Increases

Adrenal glands release vitamin C and hormones into blood

Smoking also increases the need

47

Vitamin C deficiencies

Scurvy

Bleeding gums
Capillaries under skin break spontaneously
Pinpoint hemorrhages