Biochem - Water Soluble Vitamins Flashcards by Tiffany Reid

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

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What are precursors or provitamins?

Inactive forms of vitamins

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

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What do B vitamins do?

Help the body use macronutrients for fuel

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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

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Thiamin is a part of which coenzyme?

Thiamin pyrophosphate

TPP

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Thiamine Pyrophosphate (TPP) helps in 2 processes:

Conversion of pyruvate to acetyl CoA
- removes C
TCA cycle

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

True

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Beriberi

Dry- nervous system
Muscle weakness

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

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Wernicke-Korsakoff Syndrome (WKS)

Symptoms

Mental confusion
Ataxia
Ophthalmoplegia

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Toxic levels of Thiamin? Upper limit?

No adverse effects

No UL

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Riboflavin sources

Milk
Whole grain
Dark green vegetables

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What are FMN and FAD?

Coenzyme forms of Riboflavin

Flavin mononucleotide
Flavin adenine dinucleotide

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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

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Riboflavin is destroyed by

UV light
Irradiation

So it is not stored in clear glass bottles

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Niacin chemical structures

Nicotinic acid

Nicotinamide (niacinamide)
- major form found in blood

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Coenzyme forms of Niacin

NAD

NADP

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

True

60mg of tryptophan will make 1 mg of niacin

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Deficiency of Niacin

Pellagra

The four Ds

Diarrhea
Dermatitis
Dementia
Death

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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

Niacin toxicity

Dilated capillaries

Painful tingling sensation

Biotin carries activated __

CO2

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

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

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

Avidin

Biotin absorption
Because it binds biotin

Possible benefits of nicotinic acid in large doses

Lower LDL cholesterol and triglycerides

Raise HDL

Pantothenic acid Part of? Found in?

Part of coenzyme A Widespread in food -beef, poultry, whole grains, potatoes, tomatoes, broccoli

How can pantothenic acid be destroyed? | Deficiencies?

Freezing, canning, refining processes Burning feet syndrome of WWII prisoners in Asia -usually females, at night

Forms of Vitamin B6

1. Pyridoxal 2. Pyridoxine 3. Pyridoxamine All 3 concerts coenzyme to pyridoxal phosphate (PLP)

Where is B6 found and stored?

Exclusively in muscle tissue ``` Food sources: Meats Fish Poultry Potatoes Vegetables Fruit ```

B6 deficiency (other symptoms)

Increased risk of some cancers and cardiovascular diseases Depression Confusion Convulsions Abnormal brain wave patterns

B6 toxicity

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

Folate is also known as ? Coenzyme form?

Folacin Folic acid Chemical name : PGA - pteroylglutamic acid Coenzyme form is THF - tetrahydrofolate and DHF - dihydrofolate

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

Folate

Folate deficiency

Neural tube defects Congenital birth defects anemia

Which two coenzymes of vitamin B activate each other?

Folate and B12 *synthesis of DNA and RNA

Which coenzyme of vitamin B contains cobalt?

B12

Dietary folate equivalents

Multiple micrograms consumed by 1.7

Sources of B12

Animal products - fish - milk

Choline is manufactured from __ in the body

Methionine NOT a vitamin

Common sources of choline

*essential nutrient Milk Eggs Peanuts Part of lecithin

Choline deficiencies symptoms

``` Body odor Sweating Salivation Reduced growth rate Low BP Liver damage ```

Which vitamins are water soluble?

B complex | C

Vitamin C - antioxidant properties

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

Active forms of Vitamin C

Ascorbic acid | Dehydroascorbic acid

Vitamin C is a cofactor in ___

Collagen formation Hydroxylation of carnitine Making hormones Conversion of: Trp to serotonin Tyr to norepinephrine

Other roles of vitamin C

Prevention and treatment of the common cold

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

Vitamin C deficiencies

Scurvy Bleeding gums Capillaries under skin break spontaneously Pinpoint hemorrhages