NTR 343 Final Exam Quiz Bank 2022

1. All of the following B vitamins are involved in oxidative decarboxylation of pyruvate except: c. Folate 2. Explain in scientific detail how certain foods can inhibit the absorption of thiamin. List four food examples. Some foods contain thiaminases which break the weak methylene bridge between the two rings in the thiamin structure. Example foods are raw fish, tea, shrimp, mussels, clams, fish paste, betel nuts, ferns 3. Which of the following is not a function of thiamin? c. Synthesis of FADH2 5. What is the Tolerable Upper Level of thiamin? Why was this amount established.? There is none, as it would not occur from diet. 6. Name and explain three exceptions of vitamins that do not have to be provided for in the diet. Vitamin D: synthesized in skin by high energy radiation Vitamin K: synthesized in gut by intestinal flora Niacin: converted from tryptophan in tissues Choline: synthesized in metabolism 7. Why is milk kept in a cardboard or opaque container? Milk is kept in opaque containers because the riboflavin that is found abundantly in milk is unstable and easily destroyed when exposed to UV light 8. Explain the role of FAD in the restoration of glutathione to its active form. FAD is the coenzyme for glutathione reductase; it adds hydrogens to the oxidized form of glutathione to create the reduced form that is active. 9. A dietary staple of cornbread led to pellagra in the southern United States, yet a dietary staple of corn tortillas did not cause a deficiency in niacin. Explain the scientific reason for this. Niacin in the corn meal of cornbread is bound to a protein, so the vitamin is not