Flashcards in Biochem - Water Soluble Vitamins Deck (47):
What are the main differences between vitamins and carbs/fats/proteins? Similarities?
Not linked together
No energy yielded
Measured in micrograms or mg rather than g
available from foods
What are precursors or provitamins?
Inactive forms of vitamins
Converted to active form in the body
-ex: beta carotene to vitamin A
What do B vitamins do?
Help the body use macronutrients for fuel
Coenzymes of B vitamins
Help cells to multiply
Help cells to multiply:
Thiamin is a part of which coenzyme?
Thiamine Pyrophosphate (TPP) helps in 2 processes:
1. Conversion of pyruvate to acetyl CoA
- removes C
2. TCA cycle
True or false: nerve and muscle activity depend on Thiamin.
Dry- nervous system
Wet- cardiovascular system
Dilated blood vessels, heart works harder
Kidneys retain salt and water = edema
Wernicke-Korsakoff Syndrome (WKS)
Toxic levels of Thiamin? Upper limit?
No adverse effects
Dark green vegetables
What are FMN and FAD?
Coenzyme forms of Riboflavin
Flavin adenine dinucleotide
Deficiencies in riboflavin cause:
Inflammation of membranes
- GI tract
- sore throat
- cracks/redness at corner of mouth
- painful, smooth, purplish red tongue
Riboflavin is destroyed by
So it is not stored in clear glass bottles
Niacin chemical structures
- major form found in blood
Coenzyme forms of Niacin
Niacin can be synthesized in the body, true or false?
60mg of tryptophan will make 1 mg of niacin
Deficiency of Niacin
The four Ds
How to estimate niacin equivalents
1 mg of niacin and 60 mg of Trp
2 mg of niacin or 2NE
We assume dietary protein is 1% Trp
Painful tingling sensation
Biotin carries activated __
*critical for TCA cycle
*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
Raw egg whites contain a protein called ___ that interferes with ___
Because it binds biotin
Possible benefits of nicotinic acid in large doses
Lower LDL cholesterol and triglycerides
Part of coenzyme A
Widespread in food
-beef, poultry, whole grains, potatoes, tomatoes, broccoli
How can pantothenic acid be destroyed?
Freezing, canning, refining processes
Burning feet syndrome of WWII prisoners in Asia
-usually females, at night
Forms of Vitamin B6
All 3 concerts coenzyme to pyridoxal phosphate (PLP)
Where is B6 found and stored?
Exclusively in muscle tissue
B6 deficiency (other symptoms)
Increased risk of some cancers and cardiovascular diseases
Abnormal brain wave patterns
Neurological damage in >2 grams daily for 2 months or more
Folate is also known as ?
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?
Neural tube defects
Congenital birth defects
Which two coenzymes of vitamin B activate each other?
Folate and B12
*synthesis of DNA and RNA
Which coenzyme of vitamin B contains cobalt?
Dietary folate equivalents
Multiple micrograms consumed by 1.7
Sources of B12
Choline is manufactured from __ in the body
NOT a vitamin
Common sources of choline
Part of lecithin
Choline deficiencies symptoms
Reduced growth rate
Which vitamins are water soluble?
Vitamin C - antioxidant properties
Defends against free radicals
Protects tissue from oxidative stress
Enhances iron absorption
Active forms of Vitamin C
Vitamin C is a cofactor in ___
Hydroxylation of carnitine
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?
Adrenal glands release vitamin C and hormones into blood
Smoking also increases the need