Term
| Structural components of folic acids |
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Definition
- pteridine ring
- para-aminobenzoic acid (PABA)
- glutamic acid
We cant make this, but bacteria can. |
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Term
| importance of sulfa drugs |
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Definition
- mimic PABA
- prevents bacteria from making their folic acid, so they cant grow anymore
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Term
| When the GI tract absorbs folate, what form will folate be found in |
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Definition
| coenzyme form- tetrahydrofolate (reduce 5,6 DB and 7,8 DB) |
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Term
| Proces of producing tetrahydrofolate |
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Definition
- folate and NADPH produce NADP and dihydrofolate via FH2 reductase
- dihydrofolate and NADPH produce NADP and tetrahydrofolate via FH2 reductase
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Term
| General function of tetrahydrofolate |
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Definition
- one carbon metabolism at certain oxidation states (formic acid, formaldehyde, methanol)
- add one carbon pieces to N5 position or N10 position
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Term
| Relate the various components of the folate pool |
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Definition
- N5 formyl THF, N10 formimino can irreversibly make N5,10 methenyl THF
- N10 formyl THF can reversible form N5,10 methenyl THF
- N5,10 methenyl THF can reversibly form N5,10 methylene THF
- N5,10 methylene THF irreversibly forms N5 methyl THF
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Term
| Major source of one C's for folate and process of donating C |
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Definition
- Ser
- Ser and FH4 produce N5,10 methylene THF and Gly via hydroxymethyltransferase (PLP dep.)
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Term
| If no dietary folate, what found in urine? |
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Definition
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Term
| How could definiciency in folate cause NTD |
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Definition
| your thymadilate synthase slows down, so you are not making enough DNA, so cell division goes down |
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Term
| Common complaint and presentation of patient if they are folate deficient |
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Definition
- ashy
- feel tired and have no energy
- decrease RBC, Hct, and Hb content
- see macrocytes (aka magaroblasts in peripheral smears)
- macrocytic normochromic anemia
- increase MCV
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Term
| vitamin forms and coenzyme forms of B12 |
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Definition
- vitamins
- cyanocobalamin
- hydroxycyanocobalamin
- coenzyme
- methyl B12/methly cobalamin
- adenosyl B12/5' deoxyadenosyl cobalamin
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Term
| Known B12 dependent enzymes in the body |
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Definition
- methyl malonyl CoA reductase
- homocysteine methyltransferase
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Term
| Function of transcobalamine 2 |
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Definition
| transfer B12 from liver to tissues |
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Term
| Effect of B12 deficiency on folate |
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Definition
- decrease the ability to use the storage form of folate
- inhibit methyltransferase that convert homocysteine to Met
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Term
| Way to distinguish btw folate deficiency and B12 deficiency |
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Definition
| in B12 deficiency, you will see methyl malonic aciduria and increased homocystein in the blood which could potentially lead to homocysteinuria |
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Term
| Process of SAM regenerating homocysteine |
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Definition
- SAM has an acceptor take a methyl group to form S-adenosyl homocysteine
- Adenosine is cleaved off and forms homocysteine
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Term
| Effect of B12 deficiency on myelination |
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Definition
| without it, you get demyelination of certain nerves (you may see someone looking down as they walk) |
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Term
| Process of B12 absorption |
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Definition
- saliva puts out the R binding protein which binds B12
- IF produced by parietal cells
- trypsin from pancreatic juice will cleave off the R protein from the B12 in the upper small intestines
- IF binds B12 in upper small intestiones
- IF-B12 dissociate and B12 is absorbed in a receptor in the ileum
- B12 goes into blood and binds to transcobalamin II where it can be bound to tissues
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Term
| Cause of pernicious anemia |
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Definition
- lack of RBC's due to lack of intrinsic factor
THE PROBLEM IS THE PARIETAL CELLS!!!!! |
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