A&P Chapter 25 Nutrition and Metabolism

Assuming they all weigh the same and maintain the same body temperature, which of the following would lose heat fastest? A) a short, thickly built person B) a tall, very slender person C) a person of average build

B) a tall, very slender person

In order for glycolysis to proceed, which of the following need NOT be present? A) glucose B) acetyl-CoA C) ATP D) NAD E) ADP

B) acetyl-CoA

During starvation A) carbohydrate utilization increases. B) gluconeogenesis accelerates. C) there is a decline in circulating ketone bodies. D) muscle proteins are used as an energy source. E) both B and D

B) gluconeogenesis accelerates. D) muscle proteins are used as an energy source.

A drug that blocks the action of lipoprotein lipase would

B) interfere with triglyceride utilization. C) prolong the circulation time of chylomicrons.

All of the following occur during the postabsorptive state, EXCEPT that A) glycogenolysis occurs in the liver. B) levels of blood glucose are elevated. C) ketone bodies may be formed. D) fat mobilization occurs. E) gluconeogenesis occurs in the liver.

B) levels of blood glucose are elevated.

Nitrogen compounds of the body include all of the following, EXCEPT A) amino acids. B) oxaloacetic acid. C) creatine. D) porphyrin. E) purines.

B) oxaloacetic acid.

When the temperature of the preoptic area of the hypothalamus exceeds its thermostat setting, A) peripheral vasoconstriction occurs. B) skin blood flow increases. C) tidal volume increases. D) sweat glands are inhibited. E) both B and C

B) skin blood flow increases. C) tidal volume increases.

Removal of the amino group from amino acids in the first step of their catabolism requires a coenzyme derived from vitamin ________.

B6

A cation that is essential for muscle contraction, nerve function, and blood clotting is

calcium.

The strategy of eating starchy foods for several days before an athletic event is known as

carbohydrate loading.

The end products of aerobic respiration are

carbon dioxide, water, and energy (ATP).

The major anion in body fluids is

chloride.

The largest lipoproteins, ranging in diameter up to 0.5 μm, ________ are produced by intestinal epithelial cells from the fats in food.

chylomicrons

The lipoproteins that carry absorbed lipids from the intestinal tract to the bloodstream are the

chylomicrons.

Oxygen is an important molecule in which of the following:

citric acid cycle and ETS

In the citric acid cycle, a 2 carbon molecule and a 4 carbon molecule combine to produce

citric acid.

A(n) ________ contains all of the essential amino acids.

complete protein

The trace element needed for hemoglobin synthesis is

copper.

The vitamin that is essential for the production of several clotting factors is vitamin

K

_______ is an unhealthy state resulting from inadequate intake of one or more nutrients that becomes life-threatening as the deficiencies accumulate.

Malnutrition

________ are inorganic ions released through the dissociation of electrolytes.

Minerals

_______ creates 90 percent of the ATP normally generated.

Oxidative phosphorylation

Lipogenesis generally begins with

acetyl-CoA.

The nutrients that yield the most energy per gram when metabolized are

fats.

Fatty acids and many amino acids cannot be used for________, because their catabolic pathways produce acetyl-CoA.

gluconeogenesis

Gluconeogenesis is the synthesis of ________ from noncarbohydrate precursors, such as lactic acid, glycerol, or amino acids.

glucose

Eating disorders are common among girls and young women. They result from a psychological problem that causes inadequate or excessive food consumption. Two major eating disorders are ________ and ________.

anorexia nervosa; bulimia

A(n) ________ contains all of the ingredients necessary to maintain homeostasis.

balanced diet

The ________ represents the minimum resting energy expenditures of an awake, alert individual.

basal metabolic rate or BMR

The TCA cycle

begins with the formation of a molecule of citric acid.

Sometimes called ʺgood cholesterol,ʺ ________ carry excess cholesterol from peripheral tissues to the liver.

high-density lipoproteins (HDLs)

A(n) ________ is deficient in one or more of the essential amino acids.

incomplete protein

Lipoproteins that are intermediate in size and lipid composition between VLDLs and LDLs are called ________.

intermediate-density lipoproteins (IDLs)

An element that is a component of hemoglobin, myoglobin, and cytochromes is

iron.

The vitamin that is part of the coenzyme NAD is

niacin.

A T4 assay is used to

obtain an index of metabolic activity.

The ________ of the mitochondrion contains large-diameter pores that are permeable to ions and small organic molecules such as pyruvic acid.

outer membrane

The citric acid cycle is an aerobic process because

oxygen is needed to remove carbon atoms as carbon dioxide.

The vitamin that is a constituent of coenzyme A is

pantothenic acid.

The inherited metabolic disorder that results from the accumulation of phenylketones from phenylalanine is ________.

phenylketonuria or PKU

An ion that is a necessary component of high-energy compounds and nucleic acids and a structural component of bone is the ________ ion.

phosphate

When the body is relying on internal energy reserves to continue meeting its energy demands, it is in the

postabsorptive state.

The major cation in cytoplasm is

potassium.

Lipids

provide energy for cells with modest energy demands.

A vitamin obtained from meat that is a coenzyme in amino acid and lipid metabolism is

pyridoxine (B6).

More than half the heat is lost from the body indoors through the process of

radiation.

The loss of infrared energy from the body is called

radiation.

When NAD+ is________it becomes NADH. When NADH is________it becomes NAD+.

reduced; oxidized

In the process of cellular respiration (glycolysis + oxidative), each molecule of glucose that is metabolized yields enough energy to form ________ molecules of ATP.

36

How many net ATP molecules are produced by the complete metabolism (all pathways) of one glucose molecule?

36 ATP

According to the food pyramid, there are ________ basic food groups.

5

Two individuals are the same age, sex, and ethnic background. While being tested for their BMR, Bill consumes 20 liters of oxygen/hour and Randy consumes 16 liters of oxygen/hour. Which of the two needs to consume more calories in order to maintain proper health and constant weight? A) Bill B) Randy C) neither Bill nor Randy

A) Bill

In order to determine the LDL level in a patientʹs blood it is necessary to measure

A) total cholesterol level. B) HDL level. C) triglyceride level.

The end products of glycolysis are

ATP, NADH, and pyruvic acid.

The main purpose of the citric acid cycle is to

supply hydrogen atoms to the mitochondria.

The carbon dioxide of respiration is formed during

the TCA cycle.

In oxidative phosphorylation, energy for the synthesis of ATP is directly obtained from

the movement of hydrogen ions through channels in the inner mitochondrial membrane.

The vitamin whose deficiency causes beriberi is

thiamine.

In transamination, the amino group of an amino acid is

transferred to a keto acid.

During lipolysis

triglycerides are broken down into glycerol and fatty acids.

Fatty acids that are necessary for proper health but cannot be synthesized by the body are called ________.

essential fatty acids

Linoleic acid and linolenic acid are examples of

essential fatty acids.

The vitamin that is a coenzyme in amino acid and nucleic acid metabolism is

folic acid (folate).

In glycolysis, each molecule of glucose that is catabolized gives a net yield of how many molecules of ATP?

2

What percent of energy released from catabolism is lost as heat?

60

For adults there are ________ essential amino acids.

8

The vitamin that plays a role in maintaining epithelia and is required for the synthesis of visual pigments is vitamin

A

Cells must synthesize new organic compounds

A) to support growth. B) to perform structural maintenance or repairs. C) to produce secretions. D) to store nutrient reserves.

The process of synthesizing glucose from noncarbohydrates is called ________.

gluconeogenesis

Although other nutrients can feed into the TCA cycle, ________ yields energy the quickest.

glucose

The process of glycogen formation is known as ________.

glycogenesis

A high uric acid level (above 7.4 mg/dl) can lead to the painful condition known as

gout.

Which of the following complements the actions of glucocorticoids?

growth hormone

A malfunction of the thermoregulatory mechanisms caused by fluid loss in sweat is known as

heat exhaustion.

A disorder caused by the ingestion of excessive quantities of a fat-soluble vitamin is known as

hypervitaminosis.

A growing child is in a state of

positive nitrogen balance.

The function of the TCA cycle is to

remove hydrogen atoms from organic molecules and transfer them to coenzymes.

The vitamin that is part of the coenzymes FAD and FMN is

riboflavin.

The major cation in extracellular fluid is

sodium.

Reactions within ________ provide most of the energy needed by a typical cell.

the mitochondria

The element that is necessary for the proper function of the enzyme carbonic anhydrase is

zinc.

Hydrogen atoms from one FADH2 from the citric acid cycle produce how much ATP in the Electron Transport System?

2 ATP

The chemical equation that correctly summarizes the overall reaction in oxidative phosphorylation is

2 H2 + O2 → 2 H2O.

Obesity is defined as a body weight more than ________ percent above the ideal body weight for an individual.

20

If 8 molecules of NADH from the citric acid cycle entered the ETS, how much ATP would be produced?

24 ATP

During glycolysis

A) a molecule of glucose is converted into two molecules of pyruvic acid. B) four molecules of ATP are produced. C) two molecules of ATP are consumed

Which of the following individuals would have the greater BMR? A) a nursing mother 34 years old B) a non-nursing woman 34 years old C) On average, they will be equal.

A) a nursing mother 34 years old

Compounds that cells can use to make glucose include all of the following, EXCEPT A) acetyl-CoA B) glycerol C) amino acids D) lactic acid E) pyruvic acid

A) acetyl-CoA

All of the following occur when the temperature of the preoptic area of the hypothalamus drops below its thermostat setting, EXCEPT that A) blood flow to the skin increases. B) shivering thermogenesis occurs. C) nonshivering thermogenesis occurs. D) epinephrine levels rise. E) blood returning from limbs is shunted to deep veins.

A) blood flow to the skin increases.

Cells perform catabolism to generate ATP, which can be used for

A) muscle contraction. B) ion transport. C) protein synthesis. D) glycogen synthesis.

Factors that influence an individualʹs BMR (basal metabolic rate) include all of the following, EXCEPT A) physical exertion. B) age. C) body weight. D) genetics. E) gender.

A) physical exertion.

During the absorptive state, A) the liver forms glycogen. B) adipocytes release fatty acids to the circulation. C) skeletal muscle breaks down glycogen. D) insulin levels are elevated. E) both A and D

A) the liver forms glycogen. D) insulin levels are elevated.

All of the following are true of beta-oxidation, EXCEPT that A) it occurs in the mitochondria. B) fatty acids break down into two-carbon fragments that enter the TCA cycle. C) lipids are converted into glycogen molecules. D) it requires coenzyme A, NAD, and FAD. E) it yields large amounts of ATP.

C) lipids are converted into glycogen molecules.

What is the role of NADH in metabolism? A) convert pyruvic acid into acetyl-coA B) produce bicarbonate ions for a pH buffer C) transport hydrogen atoms to coenzymes in the mitochondrial cristae D) produce carbon dioxide E)phosphorylate ADP into ATP

C) transport hydrogen atoms to coenzymes in the mitochondrial cristae

_______ are lipoproteins that are formed within the intestinal epithelium to transfer dietary fats into circulation.

Chylomicrons

The drug colestipol binds bile salts in the intestine, forming complexes that cannot be absorbed. How would this drug affect cholesterol levels in blood?

Colestipol would lead to a decrease in the plasma levels of cholesterol. Since the bile salts are bound they are not available for reabsorption in the large intestine and recycling to cholesterol in the liver and so will be lost in the feces. This deprives the body of a major source of cholesterol and the loss will need to be made up by increased liver synthesis. Overall, a drop in circulating cholesterol will result.

_______ is the direct transfer of heat energy from one object to another.

Conduction

Inadequate exposure to sunlight could result in decreased amounts of vitamin ________ in the body.

D

The vitamin that is required for proper bone growth and for calcium absorption and retention is vitamin

D

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 above E) B and C only

D) all of the above

In the electron transport chain A) NADH and FADH2 donate hydrogen atoms. B) reduced molecules transfer energy to ATP formation. C) oxidative phosphorylation leads to ATP formation. D) all of the above E) A and C only

D) all of the above

On a tour of African countries, Don contracts a bad case of travelerʹs diarrhea. Because he canʹt eat very much, his body starts to use energy sources other than carbohydrates. This would result in A) increased levels of urea in the blood. B) ketosis and a decreased blood pH. C) increased gluconeogenesis in the liver. D) all of the above E) B and C only

D) all of the above

Each cytochrome contains A) a protein. B) a pigment. C) a coenzyme. D) both A and B E) both A and C

D) both A and B - a protein. - a pigment.

Catabolism of protein is not a practical source of quick energy because of all of the following, EXCEPT that A) proteins are more difficult to break apart than lipids or carbohydrates. B) the energy yield from protein is less than the yield from lipids. C) one of the by-products of protein catabolism is ammonia. D) most individuals have little protein to spare before harming vital organs. E) extensive catabolism of protein threatens homeostasis.

D) most individuals have little protein to spare before harming vital organs.

Lipids A) deliver somewhat less energy than an equivalent mass of glucose. B) are difficult to store since they are not water soluble. C) yield quick bursts of energy. D) provide energy for cells with modest energy demands. E) are the primary nutrient metabolized in cells.

D) provide energy for cells with modest energy demands.

The major steps in oxidative phosphorylation include all of the following, EXCEPT A) removal of hydrogen atoms from a substrate molecule by coenzymes. B) ionization of hydrogen atoms. C) increasing the energy level of electrons passing through the electron transport chain. D) the breaking of carbon-carbon covalent bonds. E) the acceptance of electrons by oxygen atoms.

D) the breaking of carbon-carbon covalent bonds.

Briefly outline the role of the liver in glucose metabolism.

During the absorptive state, under insulin control, the liver takes in glucose and converts it to glycogen, the inert storage form. In the postabsorptive state, the liver releases glucose into the circulation to maintain homeostasis. The glucose comes from the glycogenolysis or gluconeogenesis. Additionally, the liver converts lactic acid released from skeletal muscle back into glucose. Epinephrine, growth hormone, glucagon, glucocorticoids, and other hormones trigger glucose release.

The vitamin that prevents breakdown of vitamin A and fatty acids is vitamin

E

Wally decides to go on a hunger strike to further one of his favorite causes. After many days with nothing but water you would expect to observe A) elevated levels of glucocorticoids. B) ketone bodies in his urine. C) elevated blood pH. D) all of the above E) A and B only

E) A and B only

Cells perform catabolism to generate ATP, which can be used for A) muscle contraction. B) ion transport. C) protein synthesis. D) glycogen synthesis. E) A ll of the answers are correct.

E) A ll of the answers are correct.

Glucocorticoids have which of the following effects on general peripheral tissues? A) They decrease the use of glucose. B) They increase gluconeogenesis. C) They increase glycogenolysis. D) A and B only E) A, B, and C

E) A, B, and C

Someone with a total cholesterol level between 200 and 239 mg/dl should A) modify their diet. B) lose weight if overweight. C) have annual checkups. D) not worry if they are physically active. E) A, B, and C

E) A, B, and C

Cells synthesize new organic components for which of the following reasons? A) structural maintenance B) growth and repair C) produce secretions D) store nutrients E) All of the answers are correct.

E) All of the answers are correct.

In the ETS, ________ accepts electrons from one molecule and transfers them to another. A) a hydrogen ion B) a coenzyme C) the acetyl group D) a cytochrome E) B or D

E) B or D

Which of the following individuals would lose heat FASTEST in a cold room? A) an adult man B) an adult woman C) an adolescent male D) a child E) a newborn infant

E) a newborn infant

In the human body, cholesterol is important because it A) helps waterproof the epidermis. B) is a lipid component of all cell membranes. C) is a key constituent of bile. D) is the precursor of several steroid hormones and vitamin D3. E) all of the above

E) all of the above

N compounds include A) amino acids. B) purines. C) pyrimidines. D) creatine. E) all of the above

E) all of the above

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 above

E) all of the above

The heat-gain center for thermoregulation A) resides in the pre-optic hypothalamus. B) activates shivering thermogenesis. C) activates nonshivering thermogenesis. D) activates skin vasoconstriction. E) all of the above

E) all of the above

Liver is to ________ as adipose tissue is to ________. A) focal point of metabolic regulation and control; storage of lipids B) storage of vitamin C; source of leptin C) cholesterol; triglycerides D) both A and B E) both A and C

E) both A and C -focal point of metabolic regulation and control; storage of lipids -cholesterol; triglycerides

Which of the following is FALSE regarding brown fat? A) is found in infants B) functions in nonshivering thermogenesis C) contains a rich vascular supply D) is innervated by the sympathetic nervous system E) is concentrated around visceral organs in the adult

E) is concentrated around visceral organs in the adult

Most of the ATP from metabolism is produced in the

Electron Transport System.

______ is the loss of heat energy by vaporizing water.

Evaporation

What happens during protein catabolism? How is this related to nitrogen balance?

Protein catabolism is the breakdown of proteins by cellular proteases and peptidases into constituent amino acids. These amino acids can be either reused for protein synthesis (anabolism) or broken down via deamination and used to make glucose or directly used in the TCA cycle to make energy. Deamination removes the nitrogen group from the amino acid, which is then excreted as ammonia or urea. This is a negative nitrogen balance.

_______ is the transfer of heat energy by emission of photons.

Radiation

List and briefly describe the bodyʹs five metabolic components.

The body has five metabolic components: the liver, adipose tissue, skeletal muscle, neural tissue, and other peripheral tissues. The liver is the focal point for metabolic regulation and control. Adipose tissue stores lipids, primarily in the form of triglycerides. Skeletal muscle contains substantial glycogen reserves, and the contractile proteins can be degraded and the amino acids used as an energy source. Neural tissue does not contain energy reserves; glucose must be supplied to it for energy. Other peripheral tissues are able to metabolize glucose, fatty acids, or other substrates under the direction of the endocrine system.

Why is the citric acid cycle called a cycle? What substances enter the cycle, and what substances leave it?

The citric acid reaction sequence is a cycle because the four-carbon starting compound (oxaloacetic acid) is regenerated at the end. Acetyl-CoA and oxaloacetic acid begin the cycle by combining to form citric acid, and then in a series of steps CO2, NADH, ATP, and FADH2 are released and oxaloacetic acid is regenerated to begin the cycle again.

________ is the homeostatic process that allows us to maintain a constant body temperature.

Thermoregulation

The presence of ketone bodies in the urine is known as

ketonuria.

The energy content of foods is commonly given in units of ________.

kilocalories (also, kcal or Cal)

The essential fatty acids are

linoleic acid and linolenic acid.

Urea is formed in the

liver.

Inside the mitochondrion, each pyruvic acid molecule

loses a carbon atom.

Lipoproteins that carry mostly cholesterol to peripheral tissues are called ________.

low-density lipoproteins (LDLs)

A cation that often acts as a cofactor for enzymes is

magnesium.

The sum of all of the biochemical processes going on within the human body at any given time is called

metabolism.

The citric acid cycle occurs in the

mitochondrial matrix.

The conversion of ammonia into a less toxic substance produces

urea.

Impaired fat absorption in the intestine would interfere with the absorption of

vitamin A.