Flashcards in Final Exam Deck (247)
What is the purpose of vitamins?
Promote growth and health maintenance
What are the two classes of water soluble vitamins?
B and C
What are the four classes of fat-soluble vitamins?
Do we need multivitamins?
Nope- can get everything from a balanced diet
Why is fortification of foods a concern for vitamins?
If too much fortification or consumption of fortified foods, can have vitamin toxicities
Why was 1994 an important year in the vitamin industry?
Supplements became unregulated based on a 1994 bill-- allowed supplements to have whatever they wanted in them; concern for toxicities; no validity required for so-called "natural" sources
Why are vitamin supplements insufficient for vitamin intake?
Don't supply phytonutrients like real food does, and doesn't provide any real-food-related health benefits from a varied diet
What needs to happen in order for the body to use vitamins?
Need to be absorbed -- won't create toxicity if not absorbed
What does it mean to be a fat soluble vitamin?
Needs to be ingested with fat and transported in chylomicrons
What does it mean to be a water soluble vitamin?
May require transport molecules or something else specific in the GI tract, but can be easily transported in aqueous solutions
What chemical group do many (all?) B vitamins function as?
coenzymes -- vitamin combines with a chemical group to form a functional coenzyme, which combines with another subunit to create the active enzyme; can be separated and reused after participating in a reaction
What does it mean for a B vitamin to become activated?
Has combined with a chemical group to create a functional enzyme subunit -- but still must combine with another enzymatic subunit to become a fully functional enzyme
What is the general function of B vitamins?
Help with energy release in metabolism; do not supply energy themselves, but can make the metabolic process more productive
Why is frozen food so high in phytonutrients?
Because can have it on the plant longer -- freeze right after it gets ripe, not before
Is organic a real thing?
Not really -- many organic farms are right next to non-organic farms, so pesticides and chemicals may travel due to soil, air, water, etc.
What are the seven B vitamins?
Thiamin, riboflavin, niacin, B6, biotin, B12, folate
What is thiamin?
First B vitamin identified: "B1" -- helps with energy production and carb metabolism
Name thiamin's function.
Assists in energy production, helps with carb metabolism (conversion of pyruvate to acetyl-coA); nervous system health (because NS uses a lot of energy)
What is thiamin deficiency?
Beri-beri ("i can't i can't) -- nervous system failure; also associated with Wernicke-Korsakoff syndrome in alcoholics
What are some sources of thiamin?
pork, lentils, bread and spaghetti from fortification
What is riboflavin?
B vitamin found in milk, pork
How does riboflavin respond to light/heat?
destroyed by light/heat -- reason for opaque milk containers
What two electron carriers is riboflavin used as a coenzyme for?
FAD and FMN (can remember because of names: "flavin etc. etc."
What part of metabolism is riboflavin important for?
electron transport chain -- used in FAD and FMn electron carriers
What is riboflavin deficiency?
ariboflavinosis (rare in US) -- inflammation in lips, mouth, tongue
What is niacin?
B vitamin synthesized from AA Trp
Where do you get niacin from?
Meat sources -- can be synthesized from Trp
How does niacin function as a coenzyme?
NAD and NADP -- "nicotinamide etc. etc." for energy release in metabolism
Where in metabolism is niacin important?
glycolysis, TCA, ETC -- used in NAD and NADP