Ch 23: metabolism

The lipoproteins that carry absorbed lipids from the intestinal tract to the bloodstream are the a) high-density lipoproteins (HDLs). b) very-low-density lipoproteins (VLDLs). c) low-density lipoproteins (LDLs). d) chylomicrons.

Chylomicrons

All cells use which of the following directly for energy to fuel their work? glycogen. ATP. sunlight. glucose.

ATP

The molecule that supplies our cells with an immediate source of energy is: glucose. glycogen. ATP. monosaccharide.

ATP

Acetyl CoA for the citric acid cycle may be formed through metabolism of: fatty acids glucose amino acids All of the above None of the above

all of the above

Regulation of body temperature is controlled by: shivering vasodilation of cutaneous vessels is regulated by a center in the hypothalamus all of the above

all of the above

A balanced diet should a) include adequate substrates for the production of energy. b) provide essential amino acids and fatty acids. c) contain adequate amounts of vitamins and minerals. d) All of the answers are correct.

all of the answers are correct

ATP can be used for a) muscle contraction. b) ion transport. c) protein synthesis. d) glycogen synthesis. e) All of the answers are correct.

all of the answers are correct

Cells synthesize new organic components for which of the following reasons? a) structural maintenance b) growth and repair c) production of secretions d) All of the answers are correct. e) None of the answers is correct.

all of the answers are correct

Glucocorticoids have which of the following effects on general peripheral tissues? a) They increase the conversion of amino acids to pyruvate. b) They increase gluconeogenesis. c) They increase glycogenolysis. d) All of the answers are correct.

all of the answers are correct

Glycolytic breakdown of glucose first results in ________ molecules. a) 2 pyruvate (pyruvic acid) b) 2 NADH c) 2 ATP (net) d) All of the answers are correct

all of the answers are correct

The electron transport system a) receives electrons from coenzymes. b) produces more the ATP than Glycolysis c) is located on the inner mitochondrial membrane (the cristae). d) All of the answers are correct.

all of the answers are correct

The food pyramid recommends many servings a day of dark-green and orange vegetables. Which vitamin is particularly abundant in this food group? a) A b) C c) E d) folic acid e) All of the answers are correct.

all of the answers are correct

Cellular respiration is best described as the: exchange of air between the lungs and the atmosphere. synthesis of glucose using the energy of ATP. breakdown of glucose into CO2 and H2O and production of ATP. conversion of CO2 and H2O into ATP.

breakdown of glucose into CO2 and H2O and production of ATP

Where in the cell does electron transport occur? matrix of mitochondria cristae of mitochondria cell membrane cytoplasm

cristae of mitochondria

Poisons like cyanide bind to ________ and prevent electron transfer. a) enzymes b) the endoplasmic reticulum c) acetyl-CoA d) cytochromes

cytochromes

During cellular respiration, which set of reactions produces the most ATP? citric acid cycle glycolysis ventilation electron transport

electron transport

During cellular respiration, which set of reactions produces water? glycolysis citric acid cycle electron transport Krebs cycle

electron transport

Most of the ATP in our cells is produced during: glycolysis. photosynthesis. electron transport. beta-oxidation.

electron transport

Which part of glucose metabolism yields the greater amount of ATP? a) glycolysis b) electron transport system c) citric acid cycle d) glycolysis + citric acid cycle

electron transport system

Fatty acids that are necessary for proper health but cannot be synthesized by the body are called a) water-soluble vitamins. b) essential fatty acids. c) high-density lipoproteins. d) low-density lipoproteins. e) chylomicrons.

essential fatty acids

The vitamin that is a coenzyme in amino acid and nucleic acid metabolism is a) pantothenic acid. b) pyridoxine (B6). c) folic acid (folate). d) vitamin C. e) vitamin K.

folic acid

Which of the following is most likely to occur if blood glucose levels are elevated? gluconeogenesis glycogenesis glycogenolysis all the above

glycogenesis

Blood glucose levels are increased by: glycogenolysis glycogenesis insulin glycosuria

glycogenolysis

When the blood glucose level becomes low, which of the following would most likely increase? glycolysis glycosuria glycogenolysis glycogenesis

glycogenolysis

A mature red blood cell has no mitochondria. Because of this, it can only make ATP by: glycolysis. the Krebs cycle. beta-oxidation. deamination.

glycolysis

If the cell starts with fat as its fuel source, which of the following reactions will NOT occur? citric acid cycle (Krebs cycle) electron transport glycolysis Beta-oxidation

glycolysis

A high uric acid level (above 7.4 mg/dl) can lead to the painful condition known as a) gout. b) rheumatoid arthritis. c) anorexia nervosa. d) lupus.

gout

The conversion of one amino acid to another: involves peptide bond formation. is not necessary, because all amino acids are obtained from our diet. is done by transamination. occurs as a normal part of the Krebs cycle.

is done by transamination

A decrease in body weight occurs when caloric intake: equals basal metabolism plus external work is greater than basal metabolism plus external work is less than basal metabolism plus external work is less than basal metabolism plus internal work

is less than basal metabolism plus external work

Body temperature: is always constant except when one has a fever is regulated primarily by regulating heat loss regulation by evaporation of sweat is important only during exercise none of the above

is regulated primarily by regulating heat loss

Epinephrine: is released from the adrenal medulla and acts to stimulate glycogenolysis levels in the blood decrease with dieting decreases glucose levels in the blood increases lipid storage

is released from the adrenal medulla and acts to stimulate glyocgenolysis

NAD, which acts as a hydrogen carrier in the cell, is derived from: thiamin. niacin (nicotinic acid). riboflavin. pyruvic acid.

niacin (nicotinic acid)

When the body is relying on internal energy reserves to continue meeting its energy demands, it is in the ________ state. a) postabsorptive b) absorptive c) starvation d) deprivation e) preabsorptive

postabsorptive

A person with untreated diabetes mellitus would be in a prolonged: absorptive state postabsorptive state catatonic state hypoglycemic state

postabsorptive state

The carbohydrates in an uneaten candy bar can best be described as: kinetic energy. ATP energy. exothermic energy. potential energy.

potential energy

In transamination, the amino group of an amino acid is ________, yielding a different amino acid. a) converted to ammonia b) converted to urea c) transferred to another molecule d) absorbed by water

transferred to another molecule

During lipolysis, a) triglycerides are converted into molecules of acetyl-CoA. b) triglycerides are broken down into glycerol and fatty acids. c) lipids are converted into glucose molecules. d) lipids are formed from excess carbohydrates.

triglycerides are broken down into glycerol and fatty acids

True or False: One of the major results of cellular respiration is heat. true false

true

True or False: When ATP breaks down, the products can then be used to synthesize more ATP. True False, because ADP --> ATP + P. False, because ATP --> glucose. False, because ATP --> ADP + ADP.

true

Carbohydrates and proteins may be converted to triglycerides and stored as fat. True. Any calorie containing nutrient can be stored as fat in the body. False. Proteins cannot be converted to fat due to the nitrogen in the amine group. False. Carbohydrates will only be stored as glycogen in the body. False. Triglycerides can only be synthesized from lipids.

true. any calorie containing nutrient can be stored as fat in the body

The conversion of ammonia into a less toxic substance produces a) ketone bodies. b) urea. c) nitrate. d) acetyl-CoA. e) water.

urea

Pellagra, an epithelial and mucosal deterioration, results from a deficiency in a) vitamin B2 (riboflavin). b) vitamin B3 (niacin). c) vitamin B9 (folic acid). d) vitamin D. e) vitamin K.

vitamin b3 niacin

The citric acid cycle a) begins with the formation of a molecule of citric acid. b) directly produces most of the ATP from the catabolism of glucose. d) contains enzymes called cytochromes. e) forms acetyl-CoA from glucose-6-phosphate.

begins with the formation of molecule of citric acid

The process that catabolizes fatty acids to acetyl-CoA is called a) lipolysis. b) lipogenesis. c) emulsification d) beta-oxidation.

beta-oxidation

Which of the following is the first step in ATP production from fat? beta-oxidation glycolysis deamination phosphorylation

beta-oxidation

In a healthy individual who has just finished eating a large nutrient-balanced meal: glucagon enhances the absorption of glucose from the intestinal tract insulin increases the excretion of glucose in the urine blood plasma will have an increased concentration of fats, glucose, and amino acids insulin decreases the entrance of glucose into most tissue cells

blood plasma will have an increased concentration of fats, glucose, and amino acids

A deficiency in vitamin D would result in which of the following disorders? a) scurvy b) night blindness c) rickets d) pernicious anemia e) pellagra

rickets

Acetyl CoA is important in cellular metabolism because it: serves as an intermediate in multiple energy pathways, for the metabolism of glucose, fatty acids, and amino acids. releases energy for cell work. is the final acceptor of electrons in the electron transport system.

serves as an intermediate in multiple energy pathways, for the metabolism of glucose, fatty acids, and amino acids

The vitamin that plays a role in maintaining epithelia and is required for the synthesis of visual pigments is vitamin a) A. b) B. c) C. d) D. e) E.

A

There are ________ essential amino acids that the body either cannot synthesize or that cannot be produced in amounts sufficient for growing children. a) 2 b) 6 c) 8 d) 10 e) 20

10

What is the net energy yield of the citric acid (Krebs) cycle? 38 ATP 34 ATP 2 ATP 4 ATP

2 ATP

Obesity is defined as a body weight more than ________ percent above the ideal body weight for an individual. a) 5 b) 10 c) 15 d) 20

20

During cellular respiration, how much of the original energy in the glucose molecule is transferred into ATP and how much is instead converted into (lost as) heat? 25% to ATP and 75% to heat. 40% to ATP and 60% to heat. 50% to ATP and 50% to heat. 60% to ATP and 40% to heat.

40% to ATP and 60% to heat

The vitamin that is required for proper bone growth and for calcium absorption and retention is vitamin a) A. b) B. c) C. d) D. e) E.

D

The "good" type of lipoprotein that carries cholesterol from tissues to liver is: HDL (high-density lipoproteins) MDL (mid-density lipoproteins) VLDL (very low-density lipoproteins) LDL (low-density lipoproteins)

HDL

Niacin (vitamin B3) is important for ATP synthesis because it forms NAD. What specific role does NAD play in energy metabolism? It removes CO2 during the Krebs cycle. It transfers hydrogens released during glycolysis and Krebs cycle to the electron transport system. It removes water during the Krebs cycle. It breaks down glucose.

It transfers hydrogens released during glycolysis and Krebs cycle to the electron transport system

Ketone bodies can result from excess production of: acetyl CoA. pyruvic acid. fats. glucose.

acetyl CoA

Amino acids and fatty acids may enter the citric acid cycle by way of: pyruvic acid. acetyl-CoA NAD. gylcerol.

acetyl-CoA

Lipogenesis generally begins with a) glucose. b) amino acids. c) fatty acids. d) acetyl-CoA.

acetyl-CoA

Which of the following does not release hydrogens that are used to make ATP in electron transport? glycolysis conversion of pyruvic acid to acetyl Co-A (pre-citric acid cycle) citric acid cycle all of these release hydrogens for use electron transport

all of these release hydrogens for use electron transport

________ is deficient in one or more of the essential amino acids. A water-soluble vitamin A fat-soluble vitamin A complete protein An incomplete protein

an incomplete protein

The largest lipoproteins, ________, are produced by intestinal epithelial cells from the fats in food. a) very-low-density lipoproteins (VLDLs) b) low-density lipoproteins (LDLs) d) high-density lipoproteins (HDLs) e) chylomicrons

chylomicrons

During cellular respiration, which set of reactions releases carbon dioxide? glycolysis citric acid (Krebs) cycle electron transport none of them produce carbon dioxide

citric acid (Krebs) cycle

A chemical reaction by which the -NH2 group is removed from an amino acid is known as: deamination. oxidation. isomerization. hydrolysis.

deamination

The vitamin that prevents breakdown of vitamin A and fatty acids is vitamin a) A. b) B. c) C. d) D. e) E.

e

Decreasing blood glucose is a stimulus for the secretion of: epinephrine glucagon growth hormone all of the above

glucagon

Which of the following hormones is most directly involved during the post-absorptive state? glycogen thyroid hormone insulin only by radiation glucagon

glucagon

The conversion of glycerol and amino acids into glucose in called: gluconeogenesis glycogenesis glycolysis glycogenolysis

gluconeogenesis

The process of synthesizing glucose from noncarbohydrates is called a) glycogenolysis. b) glycogenesis. c) glycolysis. d) gluconeogenesis.

gluconeogenesis

Although other nutrients can feed into the citric acid cycle, ________ yields energy the quickest. a) glycogen b) glucose c) protein d) fat

glucose

During the absorptive phase of metabolism: fats are broken down into glycerol and keto acids glucose is the primary energy source for most cells glycogen is converted to glucose there is an increase in ketones

glucose is the primary energy source for most cells

All of the following are reasons why glucose is the primary energy source for cells except a) glucose is a small, soluble molecule. b) glycogen breakdown occurs very slowly. c) glucose can be stored efficiently. d) glycogen breakdown involves only a single enzymatic step. e) glycolysis does not require oxygen to generate ATP.

glycogen breakdown occurs very slowly

The caloric requirements of an athlete training for a marathon would most likely be: equal to that of an elderly person equal to that of an adult who is moderately active greater than the recommended 2000 kcal/day diet for an average adult less than that of an adult who exercises moderately

greater than the recommended 2000 kcal/day diet for an average adult

t's been 5 hours since you had breakfast and now you're thinking about trying the new Mexican lunch place that just opened up across the street. The more you think about it, the hungrier you get. That's the result of the ________ that your empty stomach is releasing into your bloodstream. a) cholecystokinin (CCK) b) leptin c) ghrelin d) pepsin e) insulin

grehlin

Which of the following carry excess cholesterol from peripheral tissues to the liver? a) Very-low-density lipoproteins (VLDLs) b) Low-density lipoproteins (LDLs) d) High-density lipoproteins (HDLs)

high-density lipoproteins

A disorder caused by the ingestion of excessive quantities of a fat-soluble vitamin is known as a) protein deficiency disease. b) Kwashiorkor. c) avitaminosis. d) carbohydrate loading. e) hypervitaminosis.

hypervitaminosis

The area of the brain that regulates body temperature is the a) medulla oblongata. b) pineal gland. c) hypothalamus. d) cerebral cortex. e) pons

hypothalamus

Which of the following describes the role of NADH during cellular respiration? it carries hydrogen to the site of electron transport reactions it transports glucose to the mitochondria for use in cellular respiration it produces the oxygen needed for aerobic respiration it carries carbon dioxide to the mitochondria

it carries hydrogen to the site of electron transport reactions

All of the following take place during the absorptive state except a) ketone bodies begin to form. b) blood glucose levels rise. c) blood lipid levels rise. d) insulin stimulates glycogenesis.

ketone bodies begin to form

The energy content of foods is commonly given in units of a) ATP units. b) carbohydrate. c) grams (also, g, or gms). d) kilocalories (also, kcal or Cal). e) degrees Celsius.

kilocalories

The hormone ________, which suppresses appetite and stimulates satiety, is released by adipose tissue. a) ghrelin b) leptin c) neuropeptide Y d) insulin e) estrogen

leptin

All of the following occur during the postabsorptive state except that a) glycogen is broken down into glucose in the liver. b) levels of blood glucose are elevated. c) ketone bodies may be formed. d) lipid mobilization may occur.

levels of blood glucose are elevated

The nutrients that yield the most energy per gram when metabolized are a) carbohydrates. b) proteins. c) lipids. d) nucleic acids. e) vitamins.

lipids

All of the following are true of beta-oxidation except that a) it occurs in the mitochondria. b) fatty acids break down into acetyl-CoA that enter the citric acid cycle. c) lipids are converted into glycogen molecules. d) it requires coenzyme A, NAD, and FAD. e) it ultimately yields large amounts of ATP.

lipids are converted into glycogen molecules

Urea is formed in the a) liver. b) stomach. c) kidneys. d) small intestine. e) large intestine.

liver

During electron transport, the transfer of electrons through the cytochromes to oxygen: makes more ATP than can be made directly from glycolysis. takes place outside the mitochondria is an energy-requiring process is called the Krebs cycle

makes more ATP than can be made directly from glycolysis

When a cell needs energy, glycogen may be hydrolyzed to: many disaccharides. two fatty acid molecules. many glycerol molecules. many glucose molecules.

many glucose molecules

The sum of all of the biochemical processes going on within the human body at any given time is called a) glycolysis. b) oxidative phosphorylation. c) catabolism. d) anabolism. e) metabolism.

metabolism

The mitochondria are often called the "powerhouses" of the cell because they: synthesize glucose. produce most of the ATP (cell energy) generated from glucose. are where glycolysis, Krebs cycle, and electron transport all occur. conduct glycolysis, and therefore other pathways as well, which has to occur before any ATP can be produced.

produce most of the ATP generated from glucose

The process by which electrons are transferred from NAD through various cytochromes and finally to oxygen occurs to: provide energy for ATP formation. convert glucose into glycogen. rid cells of excess oxygen molecules. form ketone bodies from beta-oxidation.

provide energy for ATP formation

Glycolysis breaks down glucose into a) citric acid b) amino acids c) glycerol d) pyruvic acid

pyruvic acid

The function of the citric acid cycle is to a) remove hydrogen atoms from organic molecules and transfer them to coenzymes. b) transfer the acetyl group. c) hydrolyze glucose. d) produce carbon dioxide. e) produce water.

remove hydrogen atoms from organic molecules and transfer them to coenzymes

Resting energy expenditure is most directly determined by monitoring a) heart rate. b) respiration. c) body temperature. d) blood pressure. e) body weight.

respiration

Most nutrient absorption takes place in the a) small intestine. b) stomach. c) large intestine. d) duodenum. e) liver.

small intestine

The carbon dioxide of respiration is formed during a) glycolysis. b) the citric acid cycle. c) electron transport. d) all of the above

the citric acid cycles

Which of the following statements is true about carbohydrates? They contain carbon, hydrogen, and oxygen and the simplest form is a disaccharide. Their main use is to provide energy. They are stored in adipose tissue as fatty acids. All of the above are true. A and B only

their main use is to provide energy

Homeostatic control of body temperature is termed a) thermic monitoring. b) energetics. c) thermoregulation. d) basal metabolic rate.

thermoregulation

Basal metabolism most directly refers to the energy output required: to maintain basic body functions for growth of a child during old age during exercise

to maintain basic body functions