FNDH 400 Exam 4 QUESTIONS AND ANSWERS

FNDH 400 Exam 4 QUESTIONS AND ANSWERS 1-Carbon Metabolism - CORRECT ANSWERS Focused on the metabolism, or movement, of methyl groups Specifically single carbon, primarily -CH3 groups Folic Acid - CORRECT ANSWERS Synthetic Monoglutamate Oxidized form Stable Folate - CORRECT ANSWERS Natural Reduced form Contains multiple glutamates in tail Heat and light sensitive True or False -- Prior to uptake, glutamates will be cleaved off of folic acid to form the monoglutamate form - CORRECT ANSWERS False -- glutamates will be cleaved off of folate not folic acid Functions of folate/folic acid - CORRECT ANSWERS Amino acid metabolism DNA base synthesis Donates a methyl group to cobalamin forming methyl-cobalamin Folate Deficiency - CORRECT ANSWERS -Macrocytic, megaloblastic anemia -Large nucleated red blood cells -Improper red blood cell division True or False -- Spina bifida is the most common neural tube defect that results from failure of the neural tube to close properly. - CORRECT ANSWERS True Which of the following is not a reason why the United States fortifies cereals, grains and some corn masa flour with folic acid? - CORRECT ANSWERS To benefit others (men, elderly etc.) who are not women of child-bearing age -- it is meant to focus specifically on women of childbearing age B12 - CORRECT ANSWERS -Spirulina and fermented soy products are NOT reliable sources -Nutritional yeast and fortified soy milk are good sources of B12 for vegetarians/vegans -Animals consume B12 produced by microorganisms within soil or it is produced by microorganisms in their GI tracts -It is found almost exclusively in animal products Vitamin B12's scientific name - CORRECT ANSWERS Cobalamin-- contains cobalt and many amine groups Do dietary cobalamins equivalents exist? - CORRECT ANSWERS No bc the different cobalamins have similar bioavailibility 2 Cofactor forms of cobalamin - CORRECT ANSWERS -Adenosylcobalamin -Methylcobalamin Most common form of cobalamin found in supplements - CORRECT ANSWERS cyanocobalamin, with some also using methylcobalamin Cyanocobalamin - CORRECT ANSWERS Synthetic form of vitamin B12 Hapatocorrin - CORRECT ANSWERS Salivary glands released by salivary glands before being degraded by proteases in the small intestine. Intrinsic Factor - CORRECT ANSWERS Stomach is produced in the stomach, but binds to B12 in the duodenum. Transcobalamin 2 - CORRECT ANSWERS Enterocyte binds to B12 after intrinsic factor is broken down in the enterocyte after uptake. True or False -- Intrinsic factor is of particular importance to vitamin B12 absorption because uptake into the enterocyte happens through intrinsic factor +B12 binding to cubulin. - CORRECT ANSWERS True Intrinsic factor is extremely important because of its role in vitamin B12 uptake into the enterocyte. Function of Vitamin B12 - CORRECT ANSWERS -Cofactor methionine synthase -Cofactor for enzyme that breaks down odd chain fatty acids -Involved in donating methyl group to homocysteine -Important for maintaining the myelin sheath 2 symptoms of B12 deficiency - CORRECT ANSWERS -Megaloblastic (Macrocytic) Anemia -Neurological abnormalities Megaloblastic (Macrocytic) Anemia - CORRECT ANSWERS -Symptom of B12 deficiency -Same anemia that occurs in folate deficiency -Fewer, enlarged, immature red blood cells -Can occur bc there is not enough cobalamin to convert 5-methyl THF to THF as it normally would -Thus THF is not available for normal DNA synthesis & red blood cells do not divide correctly Most common cause of vitamin B12 deficiency - CORRECT ANSWERS Pernicious anemia Pernicious anemia - CORRECT ANSWERS a condition of inadequate intrinsic factor production that causes poor vitamin B12 absorption common over age of 50 (atrophic gastritis) True or False -- Atrophic gastritis can lead to pernicious anemia, which can then lead to megaloblastic (microcytic anemia) even if vitamin B12 intake is adequate. - CORRECT ANSWERS True Homocysteine - CORRECT ANSWERS Sulfur containing, non-proteinogenic (not used for making proteins) amino acid