Chapter 24 – Flashcards
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http://www.easynotecards.com/notecard_set/13471
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The link might help. Also use mastering A&P for this chapter
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the correct sequence of steps as energy is extracted from glucose during cellular respiration
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glycolysis → acetyl CoA → citric acid cycle → electron transport chain
(Glycolysis produces pyruvic acid, which enters the mitochondrion. There, it is converted to acetyl CoA, which enters the citric acid cycle. Electron carriers bring electrons from the first three steps to the electron transport chain, and ATP is made.)
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the correct general equation for cellular respiration?
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C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + ATP energy
(Cellular respiration extracts energy from glucose (C6H12O6) to produce smaller energy packets (ATP))
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Which of the following processes takes place in the cytosol of a eukaryotic cell?
ATP production by ATP synthase
acetyl CoA formation
glycolysis
electron transport chain
citric acid cycle
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Glycolysis
(Glycolysis, the breakdown of glucose into two molecules of pyruvic acid, takes place in the cytosol, outside the mitochondria.)
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In what organelle would you find acetyl CoA formation, the citric acid cycle, and the electron transport chain?
mitochondrion
nucleus
lysosome
Golgi apparatus
chloroplast
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mitochondrion
(All of the steps of cellular respiration except glycolysis take place in the mitochondrion.
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statement describes glycolysis
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This process splits glucose in half and produces 2 ATPs for each glucose.
(In glycolysis, glucose is split into two molecules of pyruvic acid. The released energy is stored in ATP and the electron carrier NADH.)
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statement describes the citric acid cycle
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This process produces some ATP and carbon dioxide in the mitochondrion.
(The citric acid cycle breaks down carbon molecules, releasing carbon dioxide and forming some ATP.
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statement describes the electron transport chain
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This process uses energy captured from electrons flowing to oxygen to produce most of the ATPs in cellular respiration.
(In the electron transport chain, electrons move from one electron carrier to another, eventually reaching oxygen. The released energy is used to make ATPs.)
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Glycolysis occurs in the __________ of cells and is an __________ process.
cytosol; aerobic
cytosol; anaerobic
mitochondria; aerobic
mitochondria; anaerobic
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cytosol; anaerobic
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The movement of H+ through the ATP synthase is best described as an example of ______.
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facilitated diffusion
(H+ cannot diffuse directly through the semipermeable phospholipid bilayer. The ATP synthase contains a channel that allows the diffusion of H+ down its concentration gradient. Diffusion of H+ releases energy that is used by the ATP synthase to phosphorylate ADP, producing ATP.)
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electron transport chain
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Transfer of electrons to the electron transport chain from NADH results in more ATP synthesis than transfer of electrons from FADH2.
Oxidation of electron carriers within the electron transport chain results in the transport of protons across the inner mitochondrial membrane.
The electron carriers within complex IV have a greater affinity for electrons than the electron carrier within complex III.
The conversion of oxygen to water only occurs as electrons exit complex IV (cytochrome oxidase). This is the last step in the electron transport chain.)
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Which term describes the breakdown of stored fats into glycerol and fatty acids?
beta oxidation
ketogenesis
lipogenesis
lipolysis
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lipolysis
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Which of the following is NOT an end product of the Krebs cycle?
citric acid
FADH2
CO2
NADH
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citric acid
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The body's rate of kilocalorie consumption needed to fuel all ongoing activities is called the __________.
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total metabolic rate
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Which of the following is NOT an essential role of the liver?
protein metabolism
urea disposal
carbohydrate metabolism
biotransformation functions
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urea disposal
(Though the liver is involved in creating urea from ammonia and carbon dioxide, it is up to the kidney to eliminate the urea thus formed.)
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Which hormone is called the "metabolic" hormone?
thyroxine
glucagon
insulin
epinephrine
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thyroxine
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During ketosis caused by inadequate ingestion of carbohydrates, ______.
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the glycogen content of the liver is reduced
(Glycogen is released from the liver when blood glucose levels are abnormally low.)
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One of the reasons why statins are effective in reducing the risk of cardiovascular disease is ______.
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they decrease the incidence of cholesterol deposition in arterial walls
(Statins help lower cholesterol by inhibiting the enzyme HMG-CoA reductase, which plays a central role in the production of cholesterol in the liver.)
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Although both conditions share the common characteristic of elevated body temperature, hyperthermia is technically different from fever because ______.
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fever is a condition in which there is a change in the body's temperature set-point
(Fever is the body's response to a systemic microbial invasion and release of pyrogens by the immune cells. These pyrogens modify the body's temperature set-point in the hypothalamus.)
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Neurons and red blood cells rely exclusively on __________ to meet their energy needs.
glycerol
proteins
fatty acids
glucose
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glucose
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Which hormone directs essentially all the events of the absorptive state?
epinephrine
insulin
growth hormone
thyroid hormone
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insulin
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Beta oxidation is the initial phase of fatty acid oxidation, and it occurs in the cytoplasm.
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False
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The increased use of noncarbohydrate molecules for energy to conserve glucose is called
glucose sparing.
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True
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Except for lactose and some glycogen, the carbohydrates we ingest are mainly from animals.
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False
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The term essential nutrient refers to the chemicals that can be interconverted in the liver so
that the body can maintain life and good health.
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False
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The most abundant dietary lipids in the diets of most Americans are triglycerides.
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True
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There are no complete proteins. All animal products should be eaten with plant material to
make a complete protein.
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False
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The body is considered to be in nitrogen balance when the amount of nitrogen ingested in
lipids equals the amount excreted in urine.
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False
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The amount of protein needed by each person is determined by the age, size, and metabolic
rate of the person.
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True
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Vitamins are inorganic compounds that are essential for growth and good health.
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False
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Cellular respiration is an anabolic process.
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False
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Glycolysis is a series of six chemical steps, most of which take place in the mitochondria.
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False
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Glycogenesis begins when ATP levels are high, and glucose entering cells is phosphorylated
to glucose-6-phosphate and converted to its isomer, glucose-1-phosphate.
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True
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All athletes require diets high in protein and calories in order to perform and to maintain
their muscle mass.
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False
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In order for amino acids to be oxidized for energy, the amine group (NH2) must be removed.
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True
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Including the ATP from glycolysis, the cell gains 34 ATP molecules from aerobic metabolism of one glucose molecule.
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False
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The body requires adequate supplies of only three minerals (calcium, sodium, chloride) and trace amounts of all others.
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False
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Processes that break down complex molecules into simpler ones are anabolic.
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False
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For use as fuel, all food carbohydrates are eventually transformed to glucose.
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True
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Triglycerides and cholesterol do not circulate freely in the bloodstream.
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True
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Normal body temperature range is 98.6-100°F, regardless of external temperature.
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False
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A deficit of potassium can cause rickets.
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False
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It would not be healthy to eliminate all fats from your diet because they serve a useful purpose in maintaining the body.
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True
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The body's thermoregulatory centers are located in the thalamus.
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False
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Carbohydrate and fat pools are oxidized directly to produce cellular energy, but amino acid pools must first be converted to a carbohydrate intermediate before being sent through cellular respiration pathways.
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True
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High levels of HDLs are considered good.
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True
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Diets high in cholesterol and saturated fats tend to produce high HDL concentrations.
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False
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Ghrelin, produced by the stomach, is a powerful appetite stimulant.
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True
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Peptides called NPY and AgRP are powerful appetite enhancers.
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True
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The primary function of carbohydrates is energy production within cells.
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True
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The molecule that serves as the major source of readily available fuel for neurons and blood cells is ________.
A) fat
B) glucose
C) acetyl CoA
D) cellulose
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B
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Which of the choices below is not a fate of carbohydrate taken into the body?
A) ATP production
B) lipogenesis
C) amino acid synthesis
D) conversion to a nucleic acid
E) glycogenesis
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D
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Dietary fats are important because they ________.
A) keep blood pressure normal
B) help the body absorb fat-soluble vitamins
C) contribute significantly to the health of the skin
D) help prevent the common cold
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B
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Cholesterol, though it is not an energy molecule, has importance in the body because it ________.
A) is a stabilizing component of the plasma membranes and is the parent molecule of steroid hormones
B) helps provide essential nutrients to the brain and lungs
C) helps mobilize fats during periods of starvation
D) enters the glycolytic pathway without being altered
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A
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Which of the following statements best describes complete protein?
A) derived from meat and fish only
B) meets all the minimum daily requirements for a healthy diet
C) derived only from legumes and other plant material
D) must meet all the body's amino acid requirements for maintenance and growth
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D
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The term metabolism is best defined as ________.
A) the length of time it takes to digest and absorb fats
B) a measure of carbohydrate utilization, typically involving measurement of calories
C) the number of calories it takes to keep from shivering on a cold day
D) biochemical reactions involved in building cell molecules or breaking down molecules for energy
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D
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The term metabolic rate reflects the ________.
A) energy the body needs to perform only its most essential activities
B) loss of organic molecules in urine
C) energy needed to make all organic molecules
D) loss of energy to perspiration
answer
A
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When proteins undergo deamination, the waste substance found in the urine is
mostly________.
A) urea
B) ammonia
C) acetyl CoA
D) ketone bodies
answer
A
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It is important to ensure that your diet is adequately rich in vitamins because ________.
A) vitamins provide protection against the common cold
B) very few foods contain vitamins
C) most vitamins are coenzymes needed to help the body utilize essential nutrients
D) all vitamins are water soluble and pass out of the body too quickly to ensure utilization
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C
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Oxidation-reduction reactions are catalyzed by which of the following enzymes?
A) dehydrogenases and oxidases
B) kinases and phosphorylases
C) phosphatases and kinases
D) synthetases and lipases
answer
A
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Which of the choices below describes the pathway of cellular respiration (the complete oxidation of glucose)?
A) glycolysis, Krebs cycle, electron transport chain, oxidative phosphorylation
B) gluconeogenesis, Krebs cycle, lipolysis
C) lipolysis, glycogenolysis, beta oxidation
D) glycogenesis, lipogenesis, electron transport chain
answer
A
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Anabolism includes reactions in which ________.
A) carbohydrate utilization increases
B) larger molecules or structures are built from smaller ones
C) structural proteins are used as a potential energy source
D) ketone bodies are formed
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B
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Catabolism would be best described as a process that ________.
A) causes a decline in circulating ketone bodies
B) builds up triglycerides during the postabsorptive state
C) breaks down complex structures to simpler ones
D) elevates glucagon levels
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C
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The primary function of cellular respiration is to ________.
A) determine the amount of heat needed by the human body
B) provide the body with adequate amounts of vitamins and minerals
C) efficiently monitor the energy needs of the body
D) break down food molecules and generate ATP
answer
D
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The process of breaking triglycerides down into glycerol and fatty acids is known as ________.
A) gluconeogenesis
B) fat utilization
C) lipogenesis
D) lipolysis
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D
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Which of the following mechanisms produces the most ATP during cellular respiration?
A) oxidative phosphorylation
B) substrate-level phosphorylation
C) oxidation-reduction reactions
D) oxidation reactions
answer
A
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Lipogenesis occurs when ________.
A) there is a shortage of fatty acids
B) glucose levels drop slightly
C) excess proteins are transported through the cell membrane
D) cellular ATP and glucose levels are high
answer
D
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Oxidative deamination takes place in the ________.
A) liver
B) muscles
C) kidneys
D) blood
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A
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Transamination is the process whereby the amine group of an amino acid is ________.
A) transferred to acetyl CoA
B) converted to urea
C) transferred to a keto acid
D) converted to ammonia
answer
C
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Glycogen is formed in the liver during the ________.
A) postabsorptive state
B) absorptive state
C) starvation period
D) period when the metabolic rate is lowest
answer
B
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Which of the following is a normal consequence of the activation of the heat-promoting center?
A) release of epinephrine
B) sympathetic sweat gland activation
C) increase in ADH production
D) vasodilation of cutaneous blood vessels
answer
A
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Gluconeogenesis is the process in which ________.
A) glycogen is broken down to release glucose
B) glucose is formed from noncarbohydrate precursors
C) glycogen is formed
D) glucose is converted into carbon dioxide and water
answer
B
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Glycolysis is best defined as a catabolic reaction based upon the ________.
A) conversion of glucose into carbon dioxide and water
B) conversion of glucose into two molecules of pyruvic acid
C) conversion of pyruvic acid into carbon dioxide and water
D) formation of sugar
answer
B
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What is the outcome of ketosis?
A) water retention and edema
B) metabolic acidosis
C) metabolic alkalosis
D) glycogen buildup
E) glucogenesis
answer
B
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Which of the choices below happens during the absorptive state?
A) Anabolic processes exceed catabolic ones.
B) Catabolic processes exceed anabolic ones.
C) No metabolism occurs.
D) Only glucose metabolism occurs.
answer
A
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In the case of a person who consumes a normal, balanced diet, proteins are essential to the
body for all of the following except ________.
A) production of energy
B) production of some hormones
C) production of enzymes, clotting factors, and antibodies
D) formation of functional molecules like hemoglobin and cytochromes
answer
A
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The most abundant dietary lipids are ________.
A) cholesterol
B) phospholipids
C) fatty acids
D) triglycerides
answer
D
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Loss of heat in the form of infrared waves is termed ________.
A) radiation
B) convection
C) conduction
D) evaporation
answer
A
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Which hormone directs essentially all the events of the absorptive state?
A) growth hormone
B) thyroid hormone
C) epinephrine
D) insulin
answer
D
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Prostaglandins play a role in ________.
A) skeletal muscle contraction
B) control of blood volume
C) noninflammatory responses
D) control of blood pressure
answer
D
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Which of the following is the most important function of the liver?
A) carbohydrate and lipid metabolism
B) synthesis of bile salts
C) processing of drugs and hormones and activation of vitamin D
D) protein metabolism
answer
D
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As the body progresses from the absorptive to the postabsorptive state, only the ________
continues to burn glucose while every other organ in the body mostly switches to fatty acids.
A) liver
B) brain
C) pancreas
D) spleen
answer
B
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In gluconeogenesis, during the postabsorptive state, amino acids and ________ are converted to glucose.
A) glycerol
B) glycogen
C) glyceraldehyde
D) glucagon
answer
A
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In the liver, the amine group of glutamic acid is removed as ________ in the oxidative state.
A) glyceraldehyde
B) pyruvic acid
C) ammonia
D) oxaloacetic acid
answer
D
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Which of the choices below is not a mechanism of heat production?
A) vasoconstriction of cutaneous blood vessels
B) shivering
C) sweating
D) enhanced thyroxine release
answer
C
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Heat-loss mechanisms do not include ________.
A) reducing activity
B) the evaporation of sweat
C) behavior measures such as wearing light, loose clothing
D) vasoconstriction of peripheral blood vessels
answer
D
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The amount of ________ produced is probably the most important hormonal factor in
determining BMR.
A) norepinephrine
B) thyroxine
C) prolactin
D) ADH
answer
B
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When ketone bodies are present in the blood and urine in large amounts, it usually indicates increased metabolism of ________.
A) amino acids
B) fatty acids
C) glycogen
D) lactic acid
answer
B
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Many factors influence BMR. What is the most critical factor?
A) the way an individual metabolizes fat
B) the way skeletal muscles break down glycogen
C) the ratio of surface area to volume (weight) of the body
D) an individual's body weight
answer
C
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The primary reason elderly people should decrease their caloric intake is that ________.
A) muscle mass and metabolism decline with age
B) their appetite begins to diminish
C) they have a higher metabolic rate and do not need large amounts of food
D) they spend most of the day at rest, and their food will quickly turn to fat
answer
A
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Which of the choices below is not a major route of heat exchange?
A) radiation
B) conduction/convection
C) evaporation
D) shivering
answer
D
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Which of the following statements is a false or incorrect statement?
A) The amino acid pool is the body's total supply of amino acids in the body's proteins.
B) Fats and carbohydrates are oxidized directly to produce cellular energy.
C) Amino acids can be used to supply energy only after being converted to a carbohydrate intermediate.
D) Excess carbohydrate and fat can be stored as such, whereas excess amino acids are oxidized for energy or converted to fat or glycogen for storage.
answer
A
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Which of the following molecules are considered key molecules at metabolic crossroads?
A) glucose-6-phosphate, pyruvic acid, acetyl CoA
B) glucose-6-phosphate, lactic acid, acetyl CoA
C) acetone, beta-hydroxybutyric acid, ATP
D) ATP, pyruvic acid, lactic acid
answer
A
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Which of the following nutrients yield the highest amount of energy per gram when
metabolized?
A) fats
B) vitamins and minerals
C) foods and beverages high in caffeine
D) proteins
answer
A
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Which of the following does not occur in the mitochondria?
A) electron transport
B) glycolysis
C) Krebs cycle
D) formation of malic acid from fumaric acid
answer
B
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Which of the following is not true of beta oxidation?
A) It occurs in the mitochondrion.
B) Every second carbon is reduced.
C) It involves the anabolism of fats.
D) Fatty acids are broken into acetic acid fragments.
answer
C
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Select the correct statement about proteins.
A) Strict vegetarians need not worry about adequate protein intake, as most vegetables are almost perfect sources of amino acids.
B) Proteins can be synthesized in the body if most of the amino acids are present.
C) Proteins will be used by most cells for ATP synthesis if insufficient carbohydrates are ingested.
D) Catabolic steroids (hormones) accelerate the rate of protein synthesis.
answer
C
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Oxidation reduction reactions ________.
A) utilize hydrogenases
B) may involve the loss of hydrogen and electrons
C) are rarely coupled together
D) occur via the gain of hydrogen or the loss of oxygen
answer
B
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What process primes a molecule to change in a way that increases its activity, produces motion, or does work?
A) phosphorylation
B) beta oxidation
C) cellular respiration
D) glycolysis
answer
A
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Which of the choices below is not a source of glucose during the postabsorptive state?
A) glycogenolysis in the liver
B) lipolysis in adipose tissues and the liver
C) absorption of glucose from the GI tract
D) catabolism of cellular protein
answer
C
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Which of the following is correct?
A) Most of the ATP are produced by substrate-level phosphorylation.
B) Oxidation of FADH2 eventually yields four ATP via oxidative phosphorylation.
C) Glycolysis relies on substrate-level oxidation for the four ATP produced in this pathway.
D) Most ATP from cellular respiration are produced directly in the Krebs cycle.
answer
B
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Which of the following food groups are considered good sources of complete proteins?
A) corn, cottonseed oil, soy oil, and wheat germ
B) lima beans, kidney beans, nuts, and cereals
C) egg yolk, fish roe, and grains
D) eggs, milk, yogurt, meat, and fish
answer
D
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Conditions that promote the oxidative deamination and energy use of amino acids include
________.
A) adequate essential amino acids
B) adequate fat calories to provide adequate ATP formation
C) excessive amounts of protein in the diet
D) ammonia combining with oxygen to form urea
answer
C
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When a person's hypothalamic thermostat is set to a higher level and the actual body temperature is below that level, the person may ________.
A) pant
B) exhibit vasodilation of skin vessels
C) perspire heavily
D) shiver
answer
D
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Glucose can be obtained from ________.
A) glycogenolysis
B) triglyceride anabolism
C) protein anabolism
D) lipogenesis
answer
A
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Which of the following is not a function of LDLs?
A) transport cholesterol from the peripheral tissues to the liver
B) regulate cholesterol synthesis in tissue cells
C) make cholesterol available to tissue cells for membrane or hormone synthesis
D) influence cholesterol synthesis in tissue cells
answer
A
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Which of the following best defines negative nitrogen balance?
A) Protein breakdown exceeds protein synthesis.
B) It is a condition usually caused by having a diet low in fish and meat.
C) A negative nitrogen balance is normal and is a way of maintaining homeostasis.
D) It occurs when amino acids are broken down by liver enzymes and carried to the bloodstream.
answer
A
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Which nutrients function as coenzymes and are needed in only small amounts?
carbohydrates
vitamins
minerals
electrolytes
answer
vitamins
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Positive nitrogen balance is more likely to be observed in the following cases except _________.
answer
starvation
question
Essential nutrients:
A) Body cannot synthesize
B) Required in diet
C) Both A & B
answer
C