Deck 22: Metabolism and Energetics

Question 1

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

A) cytoplasm
B) the plasma membrane
C) the mitochondria
D) the endoplasmic reticulum
E) none of the above

Answer 1

C

Question 2

________ carry excess cholesterol from peripheral tissues to the liver.

A) Very-low-density lipoproteins (VLDLs)
B) Low-density lipoproteins (LDLs)
C) Intermediate-density lipoproteins (IDLs)
D) High-density lipoproteins (HDLs)
E) Very-high-density lipoproteins (VHDLs)

Answer 2

D

Question 3

The carbon dioxide of respiration is formed during

A) glycolysis.
B) the citric acid cycle.
C) electron transport.
D) the formation of pyruvic acid.
E) the formation of water.

Answer 3

B

Question 4

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.
E) all of the above

Question 5

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

A) glycogen
B) glucose
C) protein
D) fat
E) All of the above have the same rate.

Question 6

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)
C) intermediate-density lipoproteins (IDLs)
D) high-density lipoproteins (HDLs)
E) chylomicrons

Question 7

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

A) the splitting of oxygen molecules.
B) the breaking of the covalent bonds in glucose.
C) the movement of hydrogen ions through channels in the inner mitochondrial membrane.
D) the combination of two atoms of hydrogen and one atom of oxygen to form water.
E) the oxidation of acetyl-CoA.

Question 8

The electron transport system

A) receives electrons from coenzymes.
B) produces energy that supports the synthesis of ATP.
C) is found on the inner mitochondrial membrane (the cristae).
D) all of the above
E) none of the above

Question 9

Figure 22-1 The Citric Acid Cycle
Use Figure 22-1 to answer the following questions:
Identify the substance labeled "4."

A) hydrogen atoms
B) citric acid
C) 4-carbon molecule
D) NADH
E) FADH₂

Question 10

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) a coenzyme or a cytochrome

Question 11

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 above
E) none of the above

Question 12

Figure 22-1 The Citric Acid Cycle
Use Figure 22-1 to answer the following questions:
Identify the molecule labeled "5."

A) fumaric acid
B) citric acid
C) 4-carbon molecule
D) malic acid
E) oxaloacetic acid

Question 13

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.
C) consumes two moles of carbon dioxide.
D) contains enzymes called cytochromes.
E) forms acetyl-CoA from glucose-6-phosphate.

Question 14

Poisons like cyanide bind to ________ and prevent electron transfer.

A) enzymes
B) the endoplasmic reticulum
C) acetyl-CoA
D) cytochromes
E) mitochondria

Question 15

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

A) muscle contraction.
B) ion transport.
C) protein synthesis.
D) glycogen synthesis.
E) all of the above

Question 16

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.

Question 17

Figure 22-1 The Citric Acid Cycle
Use Figure 22-1 to answer the following questions:
Identify the molecule labeled "2."

A) hydrogen atoms
B) citric acid
C) NADH
D) carbon dioxide
E) FADH₂

Question 18

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.

Question 19

The major job of coenzymes in oxidative phosphorylation include all of the following, except

A) release of hydrogen ions.
B) ionization of hydrogen atoms.
C) release of electrons to the first cytochrome of the electron transport chain.
D) the breaking of carbon-carbon covalent bonds.
E) none of the above

Question 20

Catabolism of all of the following is fairly common for energy production, except

A) carbohydrates.
B) lipids.
C) glucose.
D) protein.

Question 21

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 like resting skeletal muscle.
E) are difficult to store since they are not water soluble and yield quick bursts of energy.

Question 22

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

A) carbohydrates.
B) proteins.
C) fats.
D) nucleic acids.
E) vitamins.

Question 23

In the human body, cholesterol is important because it

A) is a lipid component of all cell membranes.
B) is a key constituent of bile.
C) is the precursor of several steroid hormones and vitamin D₃.
D) all of the above
E) none of the above

Question 24

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) lowered blood pH.
D) all of the above
E) none of the above

Question 25

A drug that blocks the action of lipoprotein lipase would

A) interfere with triglyceride utilization.
B) prolong the circulation time of chylomicrons.
C) all of the above
D) none of the above

Question 26

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 above
E) none of the above

Question 27

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.
E) lipids are metabolized to yield ATP.

Question 28

Lipogenesis generally begins with

A) glucose.
B) amino acids.
C) fatty acids.
D) acetyl-CoA.
E) succinyl-CoA.

Question 29

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) fat mobilization occurs.
E) gluconeogenesis occurs in the liver.

Question 30

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
E) transferred to acetyl-CoA

Question 31

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

A) HDLs.
B) VLDLs.
C) LDLs.
D) chylomicrons.
E) none of the above

Question 32

Linoleic acid and linolenic acid are examples of

A) transport proteins.
B) lipoproteins.
C) essential fatty acids.
D) essential amino acids.
E) vitamins.

Question 33

For children there are ________ essential amino acids.

A) 2
B) 6
C) 8
D) 10
E) 20

Question 34

Urea is formed in the

A) liver.
B) stomach.
C) kidneys.
D) small intestine.
E) large intestine.

Question 35

The conversion of ammonia into a less toxic substance produces

A) ketone bodies.
B) urea.
C) nitrate.
D) acetyl-CoA.
E) water.

Question 36

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

A) postabsorptive state.
B) absorptive state.
C) starvation state.
D) deprivation state.
E) preabsorptive state.

Question 37

Which of the following complements the actions of glucocorticoids?

A) insulin
B) growth hormone
C) glucagon
D) epinephrine
E) androgens

Question 38

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.

Question 39

The essential fatty acids are

A) linoleic acid and linolenic acid.
B) leucine and lysine.
C) cholesterol and glycerol.
D) HDLs and LDLs.
E) all of the above

Question 40

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) the liver forms glycogen and insulin levels are elevated.

Question 41

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

A) A.
B) B.
C) C.
D) E.
E) K.

Question 42

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

Question 43

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.

Question 44

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.

Question 45

________ creates 90 percent of the ATP normally generated.

Question 46

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.

Question 47

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.

Question 48

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

A) A.
B) B.
C) C.
D) D.
E) E.

Question 49

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

A) vitamin A.
B) vitamin B₁₂.
C) vitamin C.
D) niacin.
E) riboflavin.

Question 50

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

A) pyridoxine (B₆).
B) pantothenic acid.
C) riboflavin.
D) folic acid (folate).
E) niacin.

Question 51

The vitamin whose deficiency causes beriberi is

A) thiamine.
B) riboflavin.
C) niacin.
D) folic acid (folate).
E) cobalamin.

Question 52

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) none of the above

Question 53

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

Question 54

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
E) 30

Question 55

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

A) A
B) B₁₂
C) C
D) D
E) E

Question 56

On a tour of African countries, Don contracts a bad case of traveler's diarrhea. Because he can't 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) none of the above

Question 57

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.
E) none of the above

Question 58

Deficiency in this vitamin can result in a condition called scurvy.

A) A
B) C
C) B₁
D) B₁₂
E) D

Question 59

The vitamin that is part of coenzymes in glycolysis and the citric acid cycle is

A) thiamine.
B) riboflavin.
C) niacin.
D) folic acid (folate).
E) cobalamin.

Question 60

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

Question 61

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 ________.

Question 62

Briefly outline the role of the liver in glucose metabolism.

Question 63

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

Question 64

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

Question 65

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

Question 66

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

Question 67

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

Question 68

Ketosis develops in the postabsorptive state. What is ketosis?
Why does it develop?
What metabolic effects does it have?

Question 69

The process of synthesizing glucose from noncarbohydrates is called ________.

Question 70

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

Question 71

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

Question 72

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

Question 73

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

Question 74

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