Human Nutrition 694-300 Review for exam II Spring, 2002 The following concepts or questions you should understand (be able to apply) and feel comfortable explaining in written detail: - 1. Know the diverse functions of lipids in the body, and understand the basic health implications related to each function if fat is deficient in the diet. - 2. Understand the differences between your two major storage forms of energy. Which storage form of energy is limited and which is unlimited? Is there any advantage to having fat as the unlimited form of storage energy? - 3. Know the 3 major types of lipids found in organisms, where each is found in the body, and the main roles or functions of each. Which type of lipid makes up the vast majority of fat in the diet and in the body? - 4. Know the basic structural parts of triglycerides (TG's) and phospholipids (PL's) and what types of fatty acids are found in TG’s and PL’s, what position are certain FA’s found in the TG or PL and what purpose do they serve? - 5.What part of a TG can give you energy, what part can give you glucose? In general how is this accomplished (what organs play a role)? - 6. Understand the chemical/structural differences of saturated fatty acids (SFA's), monounsaturated fatty acids (MUFA's) and polyunsaturated fatty acids (PUFA's) and physical properties associated with each. Do fatty acids primarily occur as free fatty acids? - 7. Understand the different effects that SFA's, MUFA's and PUFA's have on LDL and HDL levels in the blood and how this translates into dietary guidelines for increasing or decreasing these in the diet. - 8. Understand the chemical differences between -3 and -6 PUFA's and where in the body are these found? How does the body make different types of -3 and -6 PUFA's? Are all of these made equally well in humans? What is meant by essential fatty acids? - 9. What are eicosanoids? How are they formed? In a very general sense, what are the differences between eicosanoids that arise from -3 PUFA's and those that arise from -6 PUFA's. What implications does this have in terms of dietary consumption of fats rich in -3 or -6 PUFA's? - 10. Understand what chemically happens to a MUFA or PUFA when it is partially hydrogenated. What are the reasons for hydrogenating a fat? A trans fatty acid arises during the process of partial hydrogenation. Chemically what is a trans fatty acid, what are the possible health effects of trans fatty acids? What types of foods are likely to contain trans fatty acids? - 11. Cholesterol, a major sterol, is found in what types of foods? Cholesterol is a precursor to what other types of sterols and what are their functions, know the structures of sterols. Also know the difference between FC and CE. - 12. What is the function of bile, where is it made and stored? Understand the process of absorbing and transporting lipids. Know where each of the lipoproteins is made. Why are lipoproteins needed? What is the basic structural arrangement of lipoproteins (core and outer layer contain what)? What is the function and role of each of the lipoproteins: chylomicrons, VLDL, LDL, HDL? - 13. What lipoprotein abnormally accumulates within the walls of an artery in atherosclerosis (coronary heart disease)? What are the genetic factors associated with increased risk to atherosclerosis? - 14. Understand and be able to basically explain why dietary and lifestyle factors are associated with atherosclerosis: elevated levels of LDL, high blood pressure, cigarette smoking, low levels of HDL, low levels of antioxidant vitamins and other dietary antioxidants, sedentary lifestyle, homocysteine etc. - 15. What element is unique to proteins as compared to carbohydrates and lipids? - 16.Understand what essential amino acids (EAA's), nonessential amino acids (NEAA's) and conditionally essential amino acids are. - 17. What differentiates one protein from another? What dictates the 3-d shape of a protein - 18. Understand what protein denaturation is, be able to give some examples of how protein is denatured, including how the body denatures proteins. - 19. Know the 10 functions of proteins. In the face of protein deficiency, understand how health would be affected in the context of any of these functions. - 20. Protein can be used for energy, is this a low or high priority for protein use? - 21. If amino acids are used for energy what must first be done to the amino acids, and what organs are involved? What is meant by some amino acids being glucogenic and some being ketogenic? - 22. Understand what protein turnover is, what positive and negative nitrogen balance are and what physiological conditions are associated with each. - 23. Understand how the dietary lack of EAA's affects the body's ability to synthesize proteins. - 24. Understand the difference between complete protein and incomplete protein, food examples. Understand what is meant by complementary proteins (mutual supplementation). - 25. What factors determine protein quality? What are the two protein-foods that have the highest protein quality. - 26. Understand the method for rating protein qualities that we talked about (PDCAAS) - 27. For food labeling purposes, the percentage daily value for protein is based on either 65 g or 50 g. Why is this, what do these two numbers represent? Be able to calculate the % daily value for protein 28. Know the protein quality differences between animal and plant protein. What other factors affect the overall "healthiness" of animal versus plant protein 29. What are the health benefits of vegetarian diets and what factors within the diet may be responsible. What nutrients may be limiting in vegetarian diets. Are there any groups who should avoid vegetarian diets and why. - 30. Are there any problems associated with excess chronic intakes of protein. Is there an upper limit RDA for protein intake and what is it? - 31. Understand that at any intermediate step in glycolysis, including pyruvate you can get back to net glucose. Understand what the possible fates of acetyl CoA are. - 32. In the context of glycolysis and the TCA cycle be able to explain why when TG's are burned for energy (in a fasted state) glycerol can give us net glucose and fatty acids can't give us glucose, but can give us energy. 33. Be able to describe the hierarchy of what happens to glucose (carbohydrate), protein, and fat in a fed state. In a fasted state be able to describe how the body uses muscle protein and stores of glycogen and fat to provide energy and maintain glucose. How does the body handle the N of protein when it is used for energy. 34. Understand what vitamins/minerals are needed in energy metabolism and where. 35. Know the parent essential fatty acids and food examples of each 36. Know the effect of the different kinds of bonds 37. What is homocysteine, what does it do, what nutrients affect it? 38. Understand how the health of the artery wall (endothelium, the inner lining of arteries) plays a role atherosclerosis (heart disease). Understand how dietary / lifestyle factors affect the artery wall. 39. What factors contribute to the oxidizablility of LDL or the protection of LDL from oxidation?