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21 Cards in this Set
- Front
- Back
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what vitamins are essential?
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all are - most can't be synthesized at all, and those that can cannot be made in necessary quantities.
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which vitamins are water soluble and which are fat soluble?
how do water soluble travel around? what's the downside of them? Ditto for fat soluble? Which can be poisonous? |
water is B and C
Fat are the rest (A, D, E, K) water soluble don't need carriers, float around freely in the blood, and are excreted when they're found in excess. downside is that they need to be replentished regularly. Fat soluble are first absorbed into LYMPH, then into BLOOD. Sometimes require protein carriers. Stored in fat. Can get in less frequent dosing. Both can be poisonous. |
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what are our B vitamins?
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B1 = thiamine
B2 = Riboflavin B3 = Niacin Biotin B5 = Pantothenic Acid B6 Folate: B12 = Cobalamin |
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Tell me about B1 uses
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B1 = Thiamin.
Found in all foods. Easily destroyed by HEAT! Thiamine is used to make Thiamin PyroPhosphate (TPP), which is necessary in several reactions: PDH complex E1: Pyruvate to Hydroxy Ethyl TPP CAC: AlphaKetogluterate Dehydrogenase Reaction Pentose Phosphate: Transketolase |
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What's up with B1 deficiency?
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All B vitamin deficiencies are rare 'cause they're so common, BUT:
Wernikie Korsakoff syndrome, associated with alcoholism. BeriBeri = B1 deficiency. |
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Tell me about B2: where is it found and what destroys it?
What's its useful pathway? Deficiencies? |
Found in dairy products, lots of grains, liver. Destroyed by irridiation and ultraviolet light.
Used as electron carrier (FAD) and flavin mononucleotide (FMN) Note - flavin structure has TRIPLE RING, NAD has only 1. Deficiencies also rare, but seen in alcoholics and in BABIES: excess bilirubin babies that are put in UV light can loose their B2 to destruction |
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B3 - where's it found? what harms it?
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B3 is in meat and grains and all that stuff. ALSO: we can make it ourselves! from tryptophan, though this is very inefficient.
Can be leached into water. |
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What's B3 good for? deficiencies? excesses?
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Makes NAD/NADP.
Deficiency in B3 = Pellagra! Excess can come from NIACIN THERAPY for post-heart attacks, lowers cholesterol. Lots of nasty side effects, rashes, etc. |
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Biotin? where from? what's it useful for? how do we get it?
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Biotin found in lots of foods, but also by intestinal bacteria/flora - so long term antibiotics can mess with this.
Used in fatty acid synthesis, carb creation, and AA metabolism: Acetyl CoA carboxylase (FA) Pyruvate carboxylase (gluconeogenesis) Propinoyl CoA Carboxylase (AA metabolism). So, 3 carboxylase reactions |
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Biotin deficiency?
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if mess too much with intestinal flora, OR eat lots of raw eggs - avidin protein has affinity for biotin and will steal it away.
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B5 - what's up?
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Again from lots of foods, destroyed by canning, freezing, or refining. Makes CO-A and ACP, necessary for everything. No major deficiencies.
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B6?
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makes PLP, destroyed by alcohol.
PLP: used in transaminations (AA/urea cycle), also in glycogen phosphorylase (using glycogen). Has a toxic level ( >500mg/day) |
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Folate?
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killed by interactions with medications, heat, oxygen (think pregnant ladies have hot flashes, are on meds, and do heavy breathing).
Dihydrofolate/tetrahydrofolate = active forms. Used for methyl group transfers (think of preggers smoking meth) needs b12 to be active (and b 12 requires it). deficiency looks like b12 - macrocytic anemia, NTD's, heart problems (folate kills homocysteine, which can cause clots). |
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B12: aka?
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cobalmin:
killed by atrophic gastritis. important for folate function. without = pernitious anemia, macrocytic anemia, etc. good for branched chain FA's, for turning homocytseine into methionine. |
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what b vitamins are sometimes found only by themselves?
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most b vitamins are not found in isolated deficiency - beriberi (B1) and pellagra (B3) are exceptions
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Vitamin C:
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easily killed by heat and oxygen
works as an antioxidant. has 2 hydrogens to donate to oxygen radicals, can easily re-accept them as well. cofactor in collagen formation. deactivates histamine (some relief to colds). involved in hydroxylations (dopamine to norepi) Toxic >3000 mg/Day. Can mess up medical tests. |
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Vitamin A:
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fat soluble.
needed for sight, for proper maintenance of mucous membranes, and growth gene regulation. sight - require cis-retinal, which light makes into trans, generates the signal for colors. toxcisity = big spleen/liver, nausea, discoloration, etc. |
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specifically, how does vitamin A control gene regulation?
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through type II/rxr (rxr = retinoid x receptor).
type II already bound to nucleus, doing repression with RXR/RAR. need vitamin A to relieve repression. |
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Vitamin D:
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steroid hormone. active form = calcitrol.
mainly regulates calcium/phosphorous. causes rickets/osteomalacea. above 40 north, may get no vitamin D during winter. |
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vitamin E:
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fat soluble antioxidant. protects A.
deficiency can cause hemolitic anemia. overdose - stop clotting dont by K. also messes with absorption of ADK. |
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Vitamin K:
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all about maintaining blood clotting factor proteins. pro-clotting factors get cleaved by K in liver,
coumadin messes with vitamin K long term antiboitics can mess with it. also, babies with no flora can have K deficiency. |
