Deck 4: Cellular Metabolism

Question 1

Which of the following is a coenzyme?

A)ATP
B)Maltase
C)FAD
D)Phosphoanhydride

Answer 1

C

Question 2

The second law of thermodynamics states that

A)energy is not created nor destroyed,but it can change into matter.
B)energy is not created nor destroyed,but it can change from one energy form to another.
C)energy organizes in a closed system and moves toward increasing order.
D)energy dissipates in a closed system and moves toward increasing disorder.

Answer 2

D

Question 3

Living organisms contain stored energy in the form of chemical compounds.When organisms die,what happens to this stored energy?

A)All molecules immediately degrade into basic elements
B)All chemicals immediately lose their high-energy bonds
C)Cells lose their organization over time and macromolecules break down because there is no longer an input of energy to maintain an organized state
D)Chemical compounds remain intact and ready to start up again unless digested by a consumer or decomposer

Answer 3

C

Question 4

The first law of thermodynamics states that

A)energy is not created nor destroyed,but it can change into matter.
B)energy is not created nor destroyed,but it can change from one energy form to another.
C)energy can be created from matter or used to produce matter.
D)energy transfers are always 100% efficient in changing energy from one useful form to another.

Question 5

Coupling occurs when energy released by an exergonic reaction is

A)used to drive another exergonic reaction.
B)used to drive an endergonic reaction.
C)lost as nonusable heat to the environment.
D)used to decrease the entropy of the universe.

Question 6

Which is true about the activity of an enzyme?

A)Lower temperatures generally increase enzyme activity.
B)Enzymes are altered or destroyed by the reaction.
C)Enzymes are not products of the reactions they catalyze.
D)Rates of reactions are independent of substrate concentration.

Question 7

The enzyme-substrate complex is

A)not strong and will freely dissociate after it stresses certain chemical bonds in a substrate.
B)secured by covalent bonds to one or more points in the active site of the enzyme.
C)able to display unique spectroscopic characteristics not seen by either the enzyme or the substrate alone.
D)proved by the saturation effect in which the reaction rate reaches a maximum even through more substrate is added.
E)all of the choices are correct.

Question 8

Cellular ____________ refers to the collective total of chemical processes that occur within living cells.

A)energy
B)thermodynamics
C)potential
D)metabolism

Question 9

When an energy-requiring reaction is driven by an energy-yielding reaction,it is called a/an

A)exergonic reaction.
B)endergonic reaction.
C)endo-exergonic reaction.
D)coupled reaction.

Question 10

If there are ten different intermediate products produced in stages leading to a molecule in a cell,we can expect that there

A)is one enzyme that carries this process through each of the ten stages to the end product.
B)is one enzyme for degradation and another enzyme for synthesis.
C)may not be any enzymes involved if this is a natural cell product.
D)are about ten enzymes,at least one responsible for each step in the metabolic pathway.

Question 11

According to the laws of physics governing energy

A)when a liter of gasoline is burned in a car engine,100% of its energy moves the car along the road.
B)when you eat a kilogram of food,you will assemble exactly a kilogram of additional body weight on your body.
C)sunlight that is absorbed on the earth eventually returns to space as dispersed heat.
D)a calorie of sunlight becomes a calorie of plant tissue that,when eaten by an animal,becomes a calorie of heat lost in muscle "power."

Question 12

Enzymes

A)lower the amount of energy present in the substrate.
B)raise the amount of energy present in the substrate.
C)lower the energy of activation of a reaction by binding to the substrate.
D)raise the energy of activation of a reaction by binding to the substrate.

Question 13

Which is true of enzyme-catalyzed reactions?

A)All enzymes promote only catabolic reactions
B)Reactions catalyzed by most enzymes tend to go predominantly in one direction
C)All enzymatic reactions are reversible and produce equal amounts of products in both directions
D)All enzymes promote only anabolic reactions

Question 14

A coenzyme is

A)an ionic cofactor that interacts with an enzyme to inhibit it.
B)a protein cofactor that interacts with an enzyme to inhibit it.
C)an ionic cofactor that interacts with an enzyme to allow it to work.
D)a protein cofactor that interacts with an enzyme to allow it to work.
E)a nonprotein organic cofactor that interacts with an enzyme to allow it to work.

Question 15

Exergonic reactions

A)are always coupling reactions.
B)can occur spontaneously.
C)can only occur if there is an input of energy.
D)All of the choices are correct.

Question 16

How do an enzyme and its substrate fit together?

A)The enzyme breaks down as product is released
B)The whole enzyme is a key that fits into the substrate that is a lock forming a new molecule product
C)Any active site is permanently changed when it interacts with the substrate
D)As the substrate binds to the enzyme,the shape of the active site changes to accommodate the reaction

Question 17

Endergonic reactions

A)are always coupling reactions.
B)occur spontaneously.
C)can only occur if there is an input of energy.
D)are associated with the release of energy.

Question 18

The net direction of any chemical reaction depends on the

A)relative energy contents of the substances involved.
B)amount of enzyme present.
C)amount of substrate present.
D)amount of ATP present.

Question 19

Which form of energy is NOT correctly associated with an example?

A)Kinetic energy: glucose
B)Kinetic energy: muscle movement
C)Potential energy: water held behind a dam
D)Kinetic energy: a ball rolling down a hill

Question 20

How specific are enzymes?

A)Many enzymes can "cross over" to catalyze reactions of different substrates in the same chemical family
B)There are 20 amino acids and therefore 20 enzymes that control all protein metabolic reactions
C)An enzyme catalyzes one reaction but it may produce one product one time,another product another time
D)An enzyme catalyzes one reaction and it produces a distinct product

Question 21

The subunits from which ATP is made are

A)ADP and inorganic phosphate.
B)FAD and NAD⁺.
C)FAD and NADPH.
D)ADP and FAD.

Question 22

Which is the true statement about oxidation-reduction reactions?

A)Reduction is the loss of electrons
B)Reduction is the loss of hydrogen atoms
C)Oxidation is the loss of electrons and reduction is the addition of electrons
D)Reduction and oxidation sometimes occur together,but not always

Question 23

Which organelle contains ATP synthetase complexes in its membrane?

A)Golgi complexes
B)Mitochondria
C)Vesicles
D)Endoplasmic reticulum

Question 24

Each turn of the Krebs cycle produces

A)2 NADH,2 FADH₂,2 ATP.
B)3 NADH,1 FADH₂,1 ATP.
C)1 NADH,3 FADH₂,2 ATP.
D)3 NADH,2 FADH₂,1 ATP.

Question 25

Which process involves chemiosmotic coupling?

A)The Krebs cycle
B)Glycolysis
C)The electron transport system
D)Fermentation

Question 26

When animals use anaerobic fermentation,which process must occur first?

A)The Krebs cycle
B)Glycolysis
C)The electron transport system
D)Fermentation

Question 27

Both NADH and FADH₂ are produced by

A)the Krebs cycle.
B)glycolysis.
C)the electron transport system.
D)oxidative phosphorylation.

Question 28

Which pairs of processes are anaerobic?

A)Glycolysis and the electron transport system
B)Fermentation and the Krebs cycle
C)Glycolysis and the Krebs cycle
D)Fermentation and glycolysis

Question 29

Animals exhale carbon dioxide that was primarily produced in

A)glycolysis.
B)the electron transport system.
C)lactate fermentation.
D)the Krebs cycle.

Question 30

What establishes an electrochemical gradient across a membrane to provide energy for ATP production?

A)The mitochondrion's electron transport system provides the ions
B)Hydrogen ions naturally collect on the outside of the organelle membrane
C)Hydrogen ions are pumped across the membrane by carrier proteins
D)All of the choices establish the electrochemical gradient

Question 31

ATP is

A)an enzyme used widely in all kinds of cells.
B)a driver of both sides of the coupled reaction that forms ADP.
C)a molecule that carries a great deal of chemical energy in the bond between the terminal two phosphates.
D)the building block of all other cell structures.

Question 32

In high levels,alcohol is toxic.Why would a creature utilize fermentation if it were wasteful of the energy in food molecules and posed the threat of killing itself?

A)The organism can survive short spells of anaerobic conditions and maintain growth and reproduction
B)If glucose levels are not high,there may be time to disperse the alcohol "waste"
C)Fermentation can provide a rapid burst of ATP since it does not have to go through the full breakdown cycle
D)All of the choices are advantages

Question 33

Full oxidative breakdown of glucose results in a net of ______ ATP molecules.

A)2
B)4
C)16
D)36

Question 34

The most accurate portrayal of ATP is that

A)ATP is a fuel.
B)ATP is a storehouse of energy set aside for some future need.
C)ATP is an energy-coupling agent and is formed and used as needed.
D)ATP is produced and consumed by the same reaction.

Question 35

The first process in breaking down glucose is

A)the Krebs cycle.
B)glycolysis.
C)the electron transport system.
D)fermentation.

Question 36

Which process occurs in the cytoplasm outside the mitochondria?

A)Krebs cycle
B)Glycolysis
C)Electron transport system
D)Substrate level phosphorylation

Question 37

Some desert mammals and beetles can live their life without ever drinking liquid water;they survive on "metabolic water." Which is the most likely source of "metabolic water?"

A)Is absorbed from the air along with respiratory oxygen.
B)Results from oxidative phosphorylation inside the mitochondria.
C)Is a breakdown product from glycolysis in the cytoplasm.
D)Is water that was never allowed to pass out the cell.

Question 38

Glycolysis produces a net yield of ____ ATP molecules.

A)2
B)4
C)8
D)10

Question 39

The critical factor that drives many microorganisms to use fermentation to metabolize sugar is

A)inability to carry on glycolysis.
B)lack of free oxygen.
C)lack of any enzymes.
D)intolerance to alcohol.

Question 40

Following glycolysis,the two molecules of pyruvic acid enter a mitochondrion where each molecule is oxidized to produce

A)glucose.
B)acetyl CoA and carbon dioxide.
C)acetyl CoA and water.
D)pyruvates and carbon dioxide.

Question 41

Aerobic metabolism requires oxygen consumption and the ultimate source of this free oxygen is generated by autotrophic organisms by the process of _______.

Question 42

Stored energy that is not doing work but has the capacity to do work is called __________ ___________.

Question 43

If the second law of thermodynamics states that a closed system moves toward increasing disorder,then how can a living system not only maintain organization but also increase it?

Question 44

Can virtually any organic compound be broken down (assuming it is non-toxic)?

Question 45

Why do some animals degrade amino acids to ammonia and others dispose of it as urea or uric acid?

Question 46

Research on lipid metabolism has resulted in pharmaceutical drugs that could help fight the obesity epidemic.Explain how these drugs might help someone lose weight.

Question 47

Discuss the recent research that claims that food intake,and therefore the amount of fat deposition,is creating a "set point" in specific parts of the brain.

Question 48

Before a chemical bond is stressed enough to break,___________ must be supplied.

Question 49

Glycolysis involves the conversion of 6-carbon glucose into 3-carbon fragments of ________ ________.

Question 50

When exergonic and endergonic reactions are coupled,which reaction involves more energy and why are the reaction energies not exactly the same?

Question 51

In the absence of oxygen,glycolysis results in glucose being degraded into two 3-carbon molecules of ______ _______.

Question 52

Aerobic organisms use _______ as the final electron acceptor in cellular respiration.

Question 53

Outline a hypothetical scenario of the evolution of metabolism.

Question 54

For some enzymes to function,small nonprotein groups called ________ must participate along with the enzyme molecule.

Question 55

Which process produces alcohol or lactate?

A)The Krebs cycle
B)Glycolysis
C)The electron transport system
D)Fermentation
E)Oxidative phosphorylation

Question 56

Because there is a constant need for amino acids to synthesize proteins,it is important to maintain ________ in the ________.

A)the Krebs cycle;mitochondria
B)glycolysis;cytoplasm
C)the electron transport system;mitochondria
D)an amino acid pool;blood

Question 57

If anaerobic glycolysis is only one-eighteenth as efficient as complete oxidation of glucose to carbon dioxide,then why would an organism use such an inefficient pathway?