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138 Cards in this Set
- Front
- Back
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The hypothalamus secretes melanocortin, which controls_______
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Satiety
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Which of the following appetite stimulants are secreted by the hypothalamus
a) leptin b) peptide YY c) neuropeptide Y d) Ghrelin |
Neuropeptide Y
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An ideal weight loss drug would stimulate _______
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Neurons that secrete melanocortin
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How many ATP molecules does anaerobic fermentation yield?
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2
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What molecule is the common branch point for either the anaerobic or aerobic pathway?
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Pyruvate
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Which of the following functions of the liver are not related to protein or amino acid metabolism?
a) transamination b) urea formation c) gamma globulin formation d) deamination |
gamma globulin formation
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The basal metabolic rate f an average adult male is _____
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2000 kcal/day
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The absorptive state lasts for ____ after a meal
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4 hours
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which of the following describes the possible result of exposure to high heat and humidity that can lead to convulsions, coma, and sudden death
a) heat cramps b) heat exhaustion c) heat stroke |
Heat stroke
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which of the following does not occur during the fasting state?
a) glycogenesis b) beta-oxidation c) lipogenesis d) gluconeogenesis |
Lipegenesis
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Which of the following is responsible for the remocal of excess cholesterol from cells and the bloodstream?
a) lipoprotein lipase b) VLDLs c) HDLs d) LDLs e) Chylomicrons |
HDLs are resonsible for the removal of excess cholesterol from cells and the blood stream
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of the following, which best describes the function of water in the body?
a) it is a direct source of energy for ATP production b) it directly functions as a coenzyme c) It supports blood volume and pressure d) it functions in immune recognition e) it forms the backbone of the structure of plasma membranes |
It supports blood voume and pressure
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What cells secrete Ghrelin? where are these cells located?
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Ghrelin is secreted by parietal cells in the fundus of the stomach, specially when the stomach is empty
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What is ghrelin? what are it's functions?
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Ghrelin is one of the signals that begins a meal. it produces the sensation of hunger and stimulates the hypothalamus to secrete growth hormone-releasing the hormone thus priming the body to take best advantage of the nutrient about to be absorbed. Within an hour after eating ghrelin secretion ceases.
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What cels secrete peptide YY (PYY)
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enteroendocrine cells in the ileum and the colon. The cells sense food as it enters the stomach and they secrete PYY before chyme reaches the ileum and in proportion to amount of calories consumed
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What is Peptide YY and what are it's functions?
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Peptide YY is one of the signals that ends a meal. the primary effect of PYY is to signal satiety and terminate eating. PYY remains elevated after a meal it acts as an ileal break that prevents the stomach from emptying to quickly, thus prolonging the sense of satiety.
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which appetite regulator prolongs sense of satiety? how?
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Peptide YY (PYY) acts as an ileum break that prevents the stomach from emptying to quickly, prolonging sense of satiety.
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Which cells secerete cholecystokinin?
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enteroendocrine cells in the duodenum and jejenum.
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Which short term regulator of appetite stimulates the secretion of pancreatic enzymes and bile?
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Cholecystokinin
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What is the function of cholecystokinin?
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Cholocystokinin (CKK) is a signal to stop eating. It stimulates the secretion of bile and pancreatic enzyme, stimulates the brain and sensory fibers of the vagus nerves to produce an appetite suppressing effect.
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What is a macronutrient?
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a nutrient that must be consumed in relatively large quantities, such as water, carbohydrates, lipids, and proteins
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Is water a micronutrient or a macronutrient?
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Macronutrient
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What are micronutrients?
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nutrients that only require a small quantity, such as, vitamins and minerals.
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Are minerals micronutrients or macronutrients?
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micronutrients
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What is a nutrient?
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Any ingested chemical that is used for growth, repair, or maintenance of the body.
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What are the major classes of nutrients?
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Water, carbohydrates, lipids, proteins, minerals, vitamins
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Of the following, which best describes the function of water in the body?
a) it is a direct source of energy for ATP production b) it directly functions as a coenzyme c) it supports blood volume and pressure d) it functions in immune recognition e) it forms the backbone of the structure of plasma membranes |
It supports blood volume and pressure
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Which of the following does not describe the essential nutrient (those that the body cannot synthesize)
a) all minerals b) most vitamins c) 15 of 20 amino acids d) 1 to 3 of the fatty acids |
15 of the 20 amino acids
- there are 8 essential amino acids that the body does not synthesize |
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Where is the site of the most carbohydrate storage?
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muscle glycogen, it stores about 325 of the average 440 g of carbohydrate in the body
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Which is less oxidized, fat or carbohydrate?
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fat is less oxidized than carbohydrate.
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Which has more energy, fat or carbohydrate? by how much?
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Fat contains twice as much energy as carbohydrate. it contains 9 kcal/g of fat and carbohydrats contains 4 kcal/g carbohydrate.
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Fat should not exceed ___ of your daily caloric intake.
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30%
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No more than ___ of your fat intake should be saturate fat.
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10%
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average cholesterol intake should not exceed _____.
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300 mg/day
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How much cholesterol does 1 egg yolk contain?
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about 240 mg
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What is the size of a low density lipoprotein?
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18-25 nm
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What does high LDL concentration mean?
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It is warning sign because it signifies a high rate of cholesterol deposition in the arteries.
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What is responsible for elevating LDL rate?
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saturated fats, cigarette smoking, coffee, and stress
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What do LDLs release? why?
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Ldls release cholesterol. Cells that need cholesterol (for membrane structure of steroid hormone synthesis) abdosrb LDLs by receptor mediated endocytosis, digest them with lysosmal enzymes and release cholesterol for intracellular use
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How much of the body's protein is in the skeletal muscles?
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65%
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protein consits of _____ of the body's mass
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12-15%
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What are essential amino acids? How many essential amino acids are there?
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They are amino acids that humans are not capable of synthesizing, and therefore, it is essential that they are included in a persons diet.
there are 8 essential amino acids 1. isoleucine 2. lysine 3. methionine 4. phenylalanine 5. tryptophan 6. valine 7. cysteine from methionine 8. tyrosine from phenylalanine |
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What is additonal amino acid is essential for infants?
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Histidine
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What are high quality complete proteins?
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those that provide all of the essential amino acids in the necessary proportions for human tissue growth, maintenance, and nitrogen balance.
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What are lower quality incomplete proteins?
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they lack one or more essential amino acids necessary for human tissue growth, maintenance, and nitrogen balance. EX: cereals are low in lysine and legumes are low in methionine.
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Do cells store surplus amino acids for later use?
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No, all amino acids necessary must be present at once. If even just one is missing the protein cannot be made
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Which of the following is not an example of metabolic role of dietary fat?
a) compact energy-storage substance b) abosorption of fat soluble vitamins--A,D,E, and K c) glucose-sparing and protein-sparing effects d) forms majority of metabolic enzymes |
Dietary fat does not form the majority of metabolic enzymes
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You want to decrese the use of animal foods in your diet. Which of the following suggestions should you follow to receive adequate protein nutrition?
a) Eat as much meat as possible since no plants provide adequate protein b) Plant foods will provide complete protein nutrition so avoiding all animal foods is a great idea c) Eating a diet high in corn and beans will provide adequate protein nutrition d) Eating a mixture of beans and rice will provide adequate protein nutrition e) Eating eggs, milk legumes, and cereals every day is the only way to receive adequate protein nutrition |
Eating a mixture of beans and rice will provide adequate protein nutrition. 2/3 of the world's population receives adequate protein nutrition from diets containing very little meat.
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Are vitamins and minerals used as fuel?
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no, but both are essential to our ability to use other nutrients.
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When an infant's blood supply is cut off during birth, all of its organs except the brain switch to what kind of metabolism?
a) glycolosis b) anaerobic fermentaion c) aerobic respiration d) none of the above |
Anaerobic respiration
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What is the most common vitamin deficiency world wide?
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Vitamin A
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What does a vitamin A deficiency cause?
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Night blindness, dry skin, dry hair, dry conjunctiva, and cloudy cornea, increased incidence of urinary, digestive, and respiratory infections
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What does an excess of vitamin A cause?
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anorexia, nausea, vomiting, headache, pain, and fragility of bones, hair loss, an enlarged liver or spline, and birth defects
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What is the final electron acceptor in aerobic respiration?
a) NAD b) cytochrome a3 c) Water d) oxygen e) FMN |
Oxygen
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What is the total number of protons donated by NADH to aeronic respiration?
a) 2 b) 8 c) 10 d) there is not enough information provided to determine |
10 molecules are donated by NADH to aerobic respiration
8 NADH (reduced coenzyme from glucose) 2 NADH generated from glycolysis |
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What is the overall reaction for glucose metabolism?
What is the function of this reaction? |
C6H12O6 + 6 O2 --> 6 O2 + 6 H2O
The function of this reaction is not to produce carbond dioxide but to transfer energy from glucose to ATP |
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What are the major pathways of glucose metabolism?
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1. Glycolysis
2. Anaerobic fermentation 3. Aerobic respiration |
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Which pathway to glucose catabolism splits glucose molecule into 2 molecules of pyruvic acid?
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Glycolosis splits 1 glucose molecule into 2 molecules of pyruvic acid
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what does anaerobic fermentaion do during glucose catabolism?
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Anaerobic fermentation takes place in the absence of oxygen and reduces pyruvic acid to lactic acid
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What is the role of aerobic respiration in glucose catabolism?
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Aerobic respiration occurs in the presence of oxygen and oxidizes pyruvic acid to carbon dioxide and water
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Approximately how many ATP molecules are generated by aerobic respiration?
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38 ATP molecules are generated by aerobic respiration
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What is a metabolic by-product of aerobic respiration?
a) lactic acid b) oxygen c) carbon dioxide d) pyruvate |
Carbon dioxide.
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What is the Chemiosmotic Mechanism?
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???
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Which of the following proteins is not part of the electon transport chain?
a) coenzyme Q b) iron-sulfur complexes c) ATP synthase d) cytochromes |
ATP-synthase
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An extreme low carbohydrate diet cases the body to rely on lipolysis for fuel. This type of diet may result in
a) alkolosis b) ketosis c) hepatic coma d) hepatitis |
Ketosis
Ketosis happens when there is not enough carbohydrate is in the diet and when carbohydrate is unavailable oxaloacetic acid is converted to glucose and becomes unavailable to the citric acid cycle. fat oxidation produces excess ketons, leading to ketosis (elevated blood ketones). This can result in pH imbalance (ketoacidosis). Ketosis is a serious risk of extreme low carbohydrate diets |
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What is glycogenesis?
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Glycogenesis is the sythesis of glycogen and is stimulated by insulin
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What is the process of glycogenesis?
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Glucose 6-phosphate (G6P) is isomerized to glucose 1-phosphate (G1P). The enzyme glycogen synthase then cleaves off the phosphate group and attaches the glucose to a growing polysccharide chain
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What is glycogenolysis?
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the hydrolysis of glycogen, it releases glucose between meals when new glucose is not being ingested.
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What is the process of glycogenolysis?
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the process is stimulated by glucagon and epinephrine. the enzyme glycogen phosphorylase begins by phosphorylating a glucose residue and splitting it off the glycogen molecule as G1P. this is isomerized to G6P, which can then enter the pathway of glycolysis
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What is gluconeogenesis?
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It is the synthesis of glucose from non carbohydrates ssuch as glycerol and amino acids. It chiefly occurs in the liver but after several weeks of fasting the kidneys also undertake this process and eventually produce just as much glucose as the liver does.
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Where does gluconeogenisis occur?
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Gluconeogenisis primarily occurs in the liver. However, after several weeks of fasting the kidneys also undertake this process and eventually produce just as much glucose as the liver
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Which of the following does not occur during fasting?
a) glycogenolysis b) beta-oxidation c) lipogensis d) gluconeogensis |
Lipogenesis does not occur during fasting.
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Which of the following terms is used to describe the removal of the amino group NH2 from an amino acid?
a) ketoamination b) amination c) deamination d) transamination |
Deamination is the removal of NH2 from an amino acid
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The Basal metabolic rate of an average male adult is ________
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2000 kcal/day
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The absorptive state lasts for about ___ after a meal
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The absorptive state lasts for about 4 hours after a meal
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What is beta oxidation?
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The process in which the fatty acid component of a triglyceride is catabolized in the mitochondrial matrix.
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How many molecule of ATP can a fatty acid of 16 carbons yield?
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129 molecules of ATP
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Are fat molecules a richer or poorer source of energy than a glucose molecule? Explain.
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They are a much richer source of energy. Each fat molecule can generate 3 fatty acids and each of those fatty acids can yield up to 129 molecules of ATP
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Where is the site of the fastest rate of tissue protein turnover?
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The intestinal mucosa, where epithelial cells are replaced at a very high rate. Dead cells are digested along with food and thus contribute to the amino acid pool.
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What is an amino acid pool?
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It is comprised of free amino acids that result from the 100g of tissue protein that breaks down daily and the amino acids from the diet. Cells can then draw upon this "pool" to make new proteins
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What is the first step in using amino acids as fuel?
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Deamination of amino acids
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What is deamination of amino acids?
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the removal of the NH2 group from an amino acid.
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What is the remainder of the molecule called once deamination of the amino acid takes place?
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Keto acid
(deamination is the removal of NH2 group from an amino acid) |
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What is radiation?
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The emission of infrared rays by removing molecules.
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All molecular motion produces ____
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Infrared rays
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Heat means _____ and all molecular motion creates _____.
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Molecular motion, infrared (IR) rays
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Why do humans lose more heat to the objects around them than they gain?
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Since humans are usually warmer than the objects around them, they usually lose more heat this way than they gain
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Which of the following statements about body heat are true? which are false?
a) most body heat comes from chemical reactions? b) ecercise greatly lowers hear generation in the muscles c) our bodies cool down by giving off infrared radiation to the objects around us d) sweat wets the skin surface and its evaporation carries heat away |
True:
-Most body heat comes from chemical reactions - our bodies cool down by giving off infrared radiation to objects around us - sweat wets the skin surface and its evaporation carries heat away False: exercise greatly lowers heat generation in the muscles |
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At res, when the air temperature is less than about 37 degrees C, the majority of the body heat is lost by
a) forced convection b) evaporation c) conduction to solids d) conduction to air e) radiation |
Radiation
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When the heat promoting center senses that blood temperature is too low what does it activate in the sympathetic nervous system?
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the sympathetic nervous system causes cutaneous vasoconstriction. Warm blood is then retained deeper in the body and less heat is lost through the skin
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Which of the following physiological responses is not controlled by the heat promoting center of the hypothalamus?
a) shivering thermogenesis b) nonshivering thermogenesis c) cutaneous vasodilation d) breakdown of brown fat |
Vasodilation is physiological response that is controlled by the heat-loss center of the hypothalamus, VasoCONTRICTION the physiological response that is controlled by the heat promoting center
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Which center of the hypothalamus controls cutaneous vasodilation?
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The heat-loss center of the hypothalamus
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What is heat exhaustion?
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Heat exhaustioin results from more severe water and electrolyte loss and is characterized by hypotension, dizziness, vomiting, and sometimes fainting.
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____ Are not used as fuel and are required in relatively small quantities
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Micronutrients
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The only significant digestible polysaccharide in the diet is____
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Starch
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Which of the following stores the greatest amount of energy for the smallest amount of space in the body?
a) glucose b) triglycerides c) glycogen d) proteins e) vitamins |
Triglycerides
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The lipoproteins that remove cholesterol from the tissues are _____
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HDLs
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Which of the following are most likely to make you hungry?
a) leptin b) ghrelin c) cholecystokinin d) peptide YY e) melanocortin |
Ghrelin
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The primary funvtion of B-complex vitamins is to act as _____
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coenzymes
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FAD is reduced to FADH2 in _____
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The citric acid cycle
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The primary, direct benefit of anaerobic fermentation is to ______
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generate NAD+
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Which of these occurs in the mitochondrial matrix?
a) glycolysis b) chemiosmosis c) cytochrome reactions d) citric acid cycle e) anaerobic fermentation |
The citric acid cycle occurs in the mitochondrial matrix
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When the body emits more infrared energy than it abosrbs, it is losing heat by_____.
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Radiation
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An _____ protein lacks one or more essential amino acids.
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Incomplete
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In the post absorptive state, glycogen is hydrolyzed to liberate glucose. This process is called _______.
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Glycogenolysis
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Synthesis of glucose from amino acids or tryglycerides is called _______.
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Gluconeogenesis
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The major nitrogenous waste resulting from protein catabolism is ______.
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Urea
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The organ that synthesizes urea is the _______.
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Liver
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The absorptive state is regulated mainly by the hormone _______.
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Insulin
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The temperature of organs in the body cavity is called _______.
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Core temperature
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The appetite hormones ghrelin, leptin, CCK, and other act on part of the hypothalamus called the ______ nucleus.
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Arcuate
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The brightly covered, iron containing, electron transfer molecules of the inner mitochondrial membrane are called _______.
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Cytochromes
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The flow of H+ from the intermembrane space to the mitochondrial matrix creates an electrical current used by the enzyme ______ to make ________.
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ATP Synthase, ATP
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True or False?
Ghrelin and leptin are two hormones that stimulate the appetite. |
False. Leptin suppresses the appetite
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True or False?
Water is a nutrient, but oxygen and cellulose are not. |
True
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True or False?
An extremely low-fat diet can cause vitamin deficiency disease. |
True
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True of false?
Most of thebody's cholesterol comes from the diet. |
False. Most cholesterol is endogenous, not from the diet
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True or false?
There is no harm in maximizing one's daily protein intake. |
False. Excessive protein intake can cause renal damage.
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True or false?
Aerobic respiration produces more ATP tan anaerobic fermentation. |
True
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True of False?
reactions occurring on the mitochondrial inner membrane produce more ATP than glycolysis and the matrix reactions combined. |
True
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True of False?
Gluconeogenesis occurs especially in the absorptive state during and shortly after a meal. |
False. Gluconeogenesis is a postabsorptive phenomenon.
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True or False?
Brown fat generates more ATP than white fat and is therefore especially important for thermoregulation. |
False. Brown fat does not generate ATP.
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True or False?
At a comfortable air temperature, the body loses more heat as infrared radiation than by any other means. |
True
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What does a high LDL: HDL ration mean?
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that a high rate of cholesterol deposition in the walls of the arteries
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True of False?
Aerobic respiration is more efficient than anaerobic respiration, but the latter is oxygen dependent |
True
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The heat promoting - center is located in the ________.
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Hypothalamus
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Glyconeogenesis and gluconeogenesis are _______ processes.
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Anabolic
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_________ yield about 4 kcal/g when completely oxidized, where as _____ yield about 9 kcal/g.
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Proteins and carbohydrates yield about 4 kcal/g and fats yield about 9 kcal/g
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Most carbohydrates and proteins are stored in __________.
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Muscular tissue
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Healthiest ratio of cholesterol is________. Why?
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High HDL:LDL
A high HDL:LDL ratio indicates that excess cholesterol is being transported to the liver for removal from the body |
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______ deficiency is the most common world wide?
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Vitamin A (retinol)
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Pyruvic acid is a product of _______.
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Glycolysis
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Most of the body's fat is stored as a ________.
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Triglyceride
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Oxidation of a typical fatty acid can yield_________.
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129 ATP
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40% of energy in glucose goes to _____. The rest is lost through _______.
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40% of energy goes to ATP and the rest is lost through body heat.
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a nude body at room temperature loses ______ of heat due to ______.
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A nude body at room temperature loses 70% of heat due to radiation
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Liver performs which of the following? which does it not responsible for?
a) detoxification b) phagocytosis c) glycogenesis d) synthesis of plasma proteins e) secretes digestive enzymes |
The liver performs
- detoxification - phagocytosis - glycogenesis - synthesizes plasma proteins The liver does not secrete digestive enzymes. It secretes bile and bile contains no digestive enzymes |
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Shivering warms the body because is increases ________.
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ATP hydrolysis
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