CH 24 Metabolism
Which of the choices below happens during the absorptive state?
A) Anabolic processes exceed catabolic ones.
Produces the most ATP
A) Krebs cycle and electron transport chain.
Which of the following is correct?
A) Oxidation of FADH2 eventually yields four ATP via oxidative phosphorylation.
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.
Glucose serves as the initial reactant.
B) Glycolysis
Occurs in the cytosol of a cell.
B) Glycolysis
Anabolism is a building process in which larger molecules are built from smaller ones, while catabolism is a tearing down process in which complex structures are degraded to simpler ones.
T
Ascorbic acid (vitamin C) is an antioxidant.
T
Before lipids can be metabolized, the fatty acids must undergo beta oxidation to be converted into two-carbon acetic acid fragments.
T
Calcium is a mineral.
T
Which of the following best defines negative nitrogen balance?
B) Protein breakdown exceeds protein synthesis.
Which of the choices below is not a source of glucose during the postabsorptive state?
B) absorption of glucose from the GI tract
Glycogen is formed in the liver during the ________.
B) absorptive state
Lipogenesis occurs when ________.
B) cellular ATP and glucose levels are high
Which of the following food groups are considered good sources of complete proteins?
B) eggs, milk, yogurt, meat, and fish
Which of the following molecules are considered key molecules at metabolic crossroads?
B) glucose-6-phosphate, pyruvic acid, acetyl CoA
In gluconeogenesis, during the postabsorptive state, amino acids and ________ are converted to glucose.
B) glycerol
Which of the following does not occur in the mitochondria?
B) glycolysis
The primary reason elderly people should decrease their caloric intake is that ________.
B) muscle mass and metabolism decline with age
Which of the following statements best describes complete protein?
B) must meet all the body's amino acid requirements for maintenance and growth
Which of the following mechanisms produces the most ATP during cellular respiration?
B) oxidative phosphorylation
Loss of heat in the form of infrared waves is termed ________.
B) radiation
Which of the following is a normal consequence of the activation of the heat-promoting center?
B) release of epinephrine
When a person's hypothalamic thermostat is set to a higher level and the actual body temperature is below that level, the person may ________.
B) shiver
Which of the following is not true of beta oxidation?
C) It involves the anabolism of fats.
Involves the removal of hydrogen electrons and CO2 from the substrate molecule.
C) Krebs cycle and electron transport chain
Involves the use of oxygen to pick up excess hydrogen and electrons.
C) Krebs cycle and electron transport chain
Select the correct statement about proteins.
C) Proteins will be used by most cells for ATP synthesis if insufficient carbohydrates are ingested.
Many factors influence BMR. What is the most critical factor?
C) the ratio of surface area to volume (weight) of the body
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.
T
Fermentation occurs when oxygen is NOT available.
T
For use as fuel, all food carbohydrates are eventually transformed to glucose.
T
Ghrelin, produced by the stomach, is a powerful appetite stimulant.
T
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.
T
High levels of HDLs are considered good.
T
In order for amino acids to be converted into lipids, they must be deaminated.
T
In order for amino acids to be oxidized for energy, the amine group (NH2) must be removed.
T
It would not be healthy to eliminate all fats from your diet because they serve a useful purpose in maintaining the body.
T
Oxidative phosphorylation is coupled to chemiosmosis.
T
Peptides called NPY and AgRP are powerful appetite enhancers.
T
The amount of protein needed by each person is determined by the age, size, and metabolic rate of the person.
T
The increased use of noncarbohydrate molecules for energy to conserve glucose is called glucose sparing.
T
The major function of HDL is to transport excess cholesterol from peripheral tissues to the liver.
T
The most abundant dietary lipids in the diets of most Americans are triglycerides.
T
The primary function of carbohydrates is energy production within cells.
T
Triglycerides and cholesterol do not circulate freely in the bloodstream.
T
Conversion of fatty acids into acetyl groups.
beta oxidation
Formation of glucose from proteins or fats.
gluconeogenesis
Storage of glucose in the form of glycogen.
glycogenesis
Breakdown of glycogen to release glucose.
glycogenolysis
Breakdown of glucose to pyruvic acid.
glycolysis
Cholesterol, though it is not an energy molecule, has importance in the body because it ________.
is a stabilizing component of the plasma membranes and is the parent molecule of steroid hormones
Formation of ketone bodies.
ketogenesis
Synthesis of lipids from glucose or amino acids.
lipogenesis
Splitting of triglycerides into glycerol and fatty acids.
lipolysis
Oxidative deamination takes place in the ________.
liver
The amount of ________ produced is probably the most important hormonal factor in determining BMR.
C) thyroxine
Transamination is the process whereby the amine group of an amino acid is ________.
C) transferred to a keto acid
In the liver, the amine group of glutamic acid is removed as ________ in the oxidative state.
D) ammonia
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.
D) brain
Catabolism would be best described as a process that ________.
D) breaks down complex structures to simpler ones
Glycolysis is best defined as a catabolic reaction based upon the ________.
D) conversion of glucose into two molecules of pyruvic acid
Conditions that promote the oxidative deamination and energy use of amino acids include ________.
D) excessive amounts of protein in the diet
The molecule that serves as the major source of readily available fuel for neurons and blood cells is ________.
D) glucose
Gluconeogenesis is the process in which ________.
D) glucose is formed from noncarbohydrate precursors
Oxidation reduction reactions ________.
D) may involve the loss of hydrogen and electrons
What is the outcome of ketosis?
D) metabolic acidosis
Vitamins are inorganic compounds that are essential for growth and good health.
F
When blood glucose levels fall, glucagon is released and causes glycogenesis.
F
The term metabolism is best defined as ________.
A) biochemical reactions involved in building cell molecules or breaking down molecules for energy
The primary function of cellular respiration is to ________.
A) break down food molecules and generate ATP
Oxidation-reduction reactions are catalyzed by which of the following enzymes?
A) dehydrogenases and oxidases
Which of the following nutrients yield the highest amount of energy per gram when metabolized?
A) fats
When ketone bodies are present in the blood and urine in large amounts, it usually indicates increased metabolism of ________.
A) fatty acids
Dietary fats are important because they ________.
A) help the body absorb fat-soluble vitamins
Which hormone directs essentially all the events of the absorptive state?
A) insulin
Anabolism includes reactions in which ________.
A) larger molecules or structures are built from smaller ones
The process of breaking triglycerides down into glycerol and fatty acids is known as ________.
A) lipolysis
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
The most abundant dietary lipids are ________.
A) triglycerides
Prostaglandins play a role in ________.
C) control of blood pressure
Which of the choices below is not a fate of carbohydrate taken into the body?
C) conversion to a nucleic acid
The term metabolic rate reflects the ________.
C) energy the body needs to perform only its most essential activities
Glucose can be obtained from ________.
C) glycogenolysis
Which of the choices below describes the pathway of cellular respiration (the complete oxidation of glucose)?
C) glycolysis, Krebs cycle, electron transport chain, oxidative phosphorylation
It is important to ensure that your diet is adequately rich in vitamins because ________.
C) most vitamins are coenzymes needed to help the body utilize essential nutrients
What process primes a molecule to change in a way that increases its activity, produces motion, or does work?
C) phosphorylation
Which of the following is the most important function of the liver?
C) protein metabolism
Which of the choices below is not a major route of heat exchange?
D) shivering
Which of the choices below is not a mechanism of heat production?
D) sweating
Which of the following is not a function of LDLs?
D) transport cholesterol from the peripheral tissues to the liver
When proteins undergo deamination, the waste substance found in the urine is mostly________.
D) urea
Heat-loss mechanisms do not include ________.
D) vasoconstriction of peripheral blood vessels
A deficit of potassium can cause rickets.
F
All athletes require diets high in protein and calories in order to perform and to maintain their muscle mass.
F
Beta oxidation is the initial phase of fatty acid oxidation, and it occurs in the cytoplasm.
F
Cellular respiration is an anabolic process.
F
Conduction is the same as radiation heat loss.
F
Diets high in cholesterol and saturated fats tend to produce high HDL concentrations.
F
Except for lactose and some glycogen, the carbohydrates we ingest are mainly from animals
F
Gluconeogenesis occurs during cell respiration in the mitochondria.
F
Glycolysis is a series of six chemical steps, most of which take place in the mitochondria.
F
In glycolysis, glucose is initially cleaved into three, two-carbon groups.
F
Including the ATP from glycolysis, the cell gains 34 ATP molecules from aerobic metabolism of one 35) glucose molecule.
F
Most required nutrients can be obtained by eating bread and meats.
F
Normal body temperature range is 98.6-100°F, regardless of external temperature.
F
Processes that break down complex molecules into simpler ones are anabolic.
F
The Krebs cycle is the partial breakdown of pyruvic acid.
F
The body is considered to be in nitrogen balance when the amount of nitrogen ingested in lipids equals the amount excreted in urine.
F
The body requires adequate supplies of only three minerals (calcium, sodium, chloride) and trace 36) amounts of all others.
F
The body's thermoregulatory centers are located in the thalamus.
F
The role of oxygen in cellular respiration is to combine with carbon during the Krebs cycle.
F
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.
F
There are no complete proteins. All animal products should be eaten with plant material to make a complete protein.
F
