Questions to Ponder Exam 2 Carbohydrates 10 18 2010 1 What are the functions of carbohydrates in the human body Main source of energy for cells Spare protein Add bulk to foods Provide energy fiber 2 What is the difference between a simple and a complex carbohydrate List the three disaccharides and the three monosaccharides Simple carbohydrate Sugars o Molecule with 6 carbon atoms and oxygen and hydrogen Complex carbohydrates Starches and fiber o Sometimes called polysaccharides o Long chains of sugar units Disaccharides o Sucrose glucose and fructose o Lactose glucose and galactose o Maltose glucose and glucose Monosaccharides o Glucose the body s predominant fuel o Fructose fruit sugar o Galactose one of the two components of the milk sugar lactose 3 What is the difference between starch fiber and glycogen Starch plant sources Fiber Plant material long chains of glucose molecules whose structure is resistant to enzymatic degradation cellulose hemicellulose pectin Glycogen animal starch configured in long chains of glucose molecules the body s storage form of carbohydrate 4 What are the benefits of consuming high fiber foods Liver uses blood cholesterol to make bile gallbladder stores bile Intestine bile aids digestion binds to fiber A little cholesterol in bile reabsorbed into the blood or fiber and bile excreted in feces Keeps one more full Slows down digestion Helps maintain healthy body weight 5 What is lactose intolerance Deficiency in the enzyme lactase where one can be nauseous have diarrhea and gas involved 6 Explain how blood glucose is regulated including which hormones are After a meal blood glucose rises o Promotes and increase in insulin release Insulin promotes glycogen formation o In liver and muscle After a while glucose levels falls o Promoting glucagon release Glucagon stimulates glycogen conversion to glucose from liver 7 Compare and contract Type I and Type 2 diabetes mellitus What are the long term side effects of the disease Type 1 IDDM o Characterized by an immune response to pancreatic B cells o Eventually the pancreas stops making insulin o Often starts early in life Type 2 NIDDM o Characterized by insulin resistance the insulin is there but it does not work to foster glucose uptake by the cells o Occurs later in life Some long term side effects include death 8 What are the three carbohydrates currently used for biofuel production Which of these is least efficient in the conversion of carbohydrate to ethanol with the current technology Sucrose sugarcane easiest Starch corn kernel Cellulose corn stalk grass wood most difficult Least efficient 10 18 2010 Lipids 1 What are the functions of lipids in our bodies and in foods Natures way of condensing energy stores o Also insulates protects organs Source of calories 9kcal gram Flavor and tenderness of food Slows stomach emptying more satiating Source of essential fatty acids 2 What are the three main types of lipids 3 How are lipids digested absorbed in the body How are they transported from the gastrointestinal tract to the liver What happens to them in the Triglycerides Phospholipids Sterols liver Digestion o Depends On Pre duodenal Lipase gastric Pancreatic Lipase Bile acids for emulsification o Lipase breaks down triglycerides into free fatty acids and monoglycerides Absorption o Short Chain Fatty Acids Portal Vein blood to liver o Monoglycerides and longer fatty acids Get repackaged as triglycerides for transport in lipoproteins Chylomicrons Enter lymph and then blood stream Transport as Lipoproteins o Chylomicrons from intestine to body o Other produced in liver VLDLs Very Low Density Lipoproteins LDLs Low Density Lipoproteins Both take TG and cholesterol to body o HDLs High Density Lipoproteins Scavengers of cholesterol brings it back to liver In the liver they make bile then goes to the gallbladder where it is stored until it is needed for digestion and absorption of fats 4 What are the differences between saturated and unsaturated fatty acids in terms of chemical structure where they are found in our diet and their impact upon human health Saturated Fatty Acid o Chemical structure A fatty acid carrying the maximum number of hydrogen atoms o Found in animal fats o Impact Unsaturated Fatty Acid o Chemical structure A fatty acid with less than maximum hydrogen atoms monosaturated fatty acid polyunsaturated fatty acid o Found in vegetable oils olive oil o Impact 5 What is trans fat Where is trans fat found in the human diet Why are we advised to eat minimal trans fat Fatty acids with unusual shapes Arise when polyunsaturated oils are hyrodenated o Advantage Control consistency and oxidation of fats o Disadvantage Increase LDL Found in margarines shortenings baked goods 6 What are the two essential fatty acids Where are they found in our diet Why is it important to have the proper balance of these two fatty acids in the diet Omega 3 Fatty Acids Omega 6 Fatty Acids vegetable oil more than omega 3 fatty acids Made in limited amounts in the body Abundant in fish oils Prevent against irregular heartbeats May reduce inflammation Essential for normal infant growth and development May support immune system May inhibit cancer 7 What is the function of a lipoprotein List the three main types of human lipoproteins and describe the function of each Used to assess risk of heart diseases Total cholesterol LDLs associated with increased risk o Less healthy want low HDLs associated with decreased risk o Healthy want high blood Total cholesterol 200 HDL 40 LDL 130 8 What are the desirable values for total cholesterol HDL and LDL in our Proteins 10 18 2010 1 What the functions of proteins in the body How much protein does the average person need Build new tissue Functional unit a few to thousands amino acids o Enzymes o Hormones o Antibodies Physiology metabolism o Fluid and electrolyte balance o Acid base balance o Energy o Transportation e g Lipoproteins o Blood clotting The DRI recommendation for protein intake depends on size and stage of growth DRI recommended intake is 0 8 grams per kilogram of body weight Minimum is 10 percent of total calories Athletes may need slightly more 1 0 gram per kg 2 What is an essential amino acid What are the nine essential amino acids Essential amino acid not made by us Histidine Isoleucine Leucine Lysine Methionine Phenylalanine Threonine Tryptophan Valine 3 What are marasmus and kwashiorkor What causes each What are the symptoms of each Marasmum o Chronic inadequate food intake
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