Question 1

Why do metabolic pathways require tens to hundreds of different enzymes?

Accepted Answer

A)  The enzymes are used up after one reaction and the molecules have to undergo multiple rearrangements. 
B)  The enzyme is deformed by the interaction with the substrate and needs a period of time to return to its original reactive form, so many enzymes are needed to keep the pathway going. 
C)  Each enzyme has a specific substrate and produces a specific product. 
D)  Multiple enzymes are not required for the pathway, but having them speed up the production of the final product. 
E)  The enzymes are attached to a membrane and cannot move to the location of the new intermediate, so having a long line of enzymes to carry out the reaction allows the reaction to occur faster. 
A)  The enzymes are used up after one reaction and the molecules have to undergo multiple rearrangements. 
B)  The enzyme is deformed by the interaction with the substrate and needs a period of time to return to its original reactive form, so many enzymes are needed to keep the pathway going. 
C)  Each enzyme has a specific substrate and produces a specific product. 
D)  Multiple enzymes are not required for the pathway, but having them speed up the production of the final product. 
E)  The enzymes are attached to a membrane and cannot move to the location of the new intermediate, so having a long line of enzymes to carry out the reaction allows the reaction to occur faster. C

Question 2

Both starch and cellulose are made by stringing together many glucose molecules, but starch is easily digested by humans, while cellulose is indigestible. The starch polysaccharide has every bond occurring below the sugar rings while the bonds in cellulose alternate between one bond above the ring and the next below the ring. How can you explain humans' inability to digest cellulose?

Accepted Answer

A)  The enzyme that breaks down starch can only fit the specific bond configuration of bonds below the ring. 
B)  Humans do not eat cellulose. 
C)  The acidic molecules found in stomach acid cannot act on the bonds that are above the sugar rings in cellulose. 
D)  The alternating bonds make the cellulose molecule too large and bulky to enter cells for digestion. 
E)  Cellular respiration is only capable of breaking down specific bonds. 
A)  The enzyme that breaks down starch can only fit the specific bond configuration of bonds below the ring. 
B)  Humans do not eat cellulose. 
C)  The acidic molecules found in stomach acid cannot act on the bonds that are above the sugar rings in cellulose. 
D)  The alternating bonds make the cellulose molecule too large and bulky to enter cells for digestion. 
E)  Cellular respiration is only capable of breaking down specific bonds. A

Question 3

Which of the following statements correctly describes an energy transformation in living organisms?

Accepted Answer

A)  Chloroplasts convert solar energy to the chemical energy of nutrient molecules. 
B)  Mitochondria convert ATP molecules into glucose. 
C)  Chloroplasts produce CO 2 and H 2O during photosynthesis. 
D)  Mitochondria capture solar energy and convert it to oxygen. 
E)  Chloroplasts burn glucose into ATP molecules during cell respiration. 
A)  Chloroplasts convert solar energy to the chemical energy of nutrient molecules. 
B)  Mitochondria convert ATP molecules into glucose. 
C)  Chloroplasts produce CO 2 and H 2O during photosynthesis. 
D)  Mitochondria capture solar energy and convert it to oxygen. 
E)  Chloroplasts burn glucose into ATP molecules during cell respiration. A

Question 4

Which one of the following molecules is able to move across the cell membrane by simple diffusion?

Accepted Answer

A)  DNA 
B)  hemoglobin 
C)  carbon dioxide 
D)  glucose 
E)  starch 
A)  DNA 
B)  hemoglobin 
C)  carbon dioxide 
D)  glucose 
E)  starch

Question 5

Which of the following is best associated with a coupled reaction?

Accepted Answer

A)  ATP consumes energy from another metabolic reaction. 
B)  ADP often transfers a phosphate to the reactant. 
C)  The breakdown of ATP generally releases more energy (and heat) than is needed to power the metabolic reaction. 
D)  ATP gains a phosphate group during the metabolic reaction. 
E)  ADP is used up in the metabolic reaction. 
A)  ATP consumes energy from another metabolic reaction. 
B)  ADP often transfers a phosphate to the reactant. 
C)  The breakdown of ATP generally releases more energy (and heat) than is needed to power the metabolic reaction. 
D)  ATP gains a phosphate group during the metabolic reaction. 
E)  ADP is used up in the metabolic reaction.

Question 6

Molecules move from greater to lesser concentration through a carrier protein in

Accepted Answer

A)  simple diffusion. 
B)  facilitated diffusion. 
C)  pinocytosis. 
D)  active transport. 
E)  phagocytosis. 
A)  simple diffusion. 
B)  facilitated diffusion. 
C)  pinocytosis. 
D)  active transport. 
E)  phagocytosis.

Question 7

Which statement most accurately describes the second law of thermodynamics?

Accepted Answer

A)  Energy cannot be changed from one form to another without a loss of usable energy. 
B)  One usable form of energy can be completely converted into another usable form. 
C)  Energy cannot be created or destroyed, but it can be changed from one form to another. 
D)  Energy can be created or destroyed. 
E)  Energy can be recycled within an ecosystem. 
A)  Energy cannot be changed from one form to another without a loss of usable energy. 
B)  One usable form of energy can be completely converted into another usable form. 
C)  Energy cannot be created or destroyed, but it can be changed from one form to another. 
D)  Energy can be created or destroyed. 
E)  Energy can be recycled within an ecosystem.

Question 8

Considering the ATP cycle, which of the following would have the most potential energy to perform work for cell activities?

Accepted Answer

A)  ATP 
B)  ADP 
C)  adenosine 
D)  AMP 
E)  H + ions 
A)  ATP 
B)  ADP 
C)  adenosine 
D)  AMP 
E)  H + ions

Question 9

If blood cells are placed in a hypertonic solution, the cells will

Accepted Answer

A)  shrink due to water loss by the cell. 
B)  be unaffected since they have a cell membrane to separate them from the solution. 
C)  swell due to diffusion. 
D)  burst due to active transport. 
E)  shrink due to the loss of solutes from the blood cell. 
A)  shrink due to water loss by the cell. 
B)  be unaffected since they have a cell membrane to separate them from the solution. 
C)  swell due to diffusion. 
D)  burst due to active transport. 
E)  shrink due to the loss of solutes from the blood cell.

Question 10

The concentration of calcium in a cell is 3%. The concentration of calcium in the surrounding fluid is 1%. Which of the following processes could the cell use to obtain more calcium?

Accepted Answer

A)  passive transport 
B)  diffusion 
C)  active transport 
D)  osmosis 
E)  pinocytosis 
A)  passive transport 
B)  diffusion 
C)  active transport 
D)  osmosis 
E)  pinocytosis

Question 11

During an osmosis experiment, you place some plant cells under the microscope. You notice the cells seem very swollen. What type of solution were the cells immersed in?

Accepted Answer

A)  isotonic 
B)  ionic 
C)  hypotonic 
D)  hypertonic 
E)  salt 
A)  isotonic 
B)  ionic 
C)  hypotonic 
D)  hypertonic 
E)  salt

Question 12

The part of the enzyme into which the substrate fits is called the

Accepted Answer

A)  feedback site. 
B)  active site. 
C)  substrate location. 
D)  inhibitor. 
E)  solute. 
A)  feedback site. 
B)  active site. 
C)  substrate location. 
D)  inhibitor. 
E)  solute.

Question 13

Less energy is needed to bring about a reaction when an enzyme is present.

Accepted Answer

A) True 
 B)False

Question 14

What prevents a plant cell from bursting in a hypotonic solution?

Accepted Answer

A)  plasma membrane 
B)  transport proteins, which help pump the excess water out of the cell 
C)  the presence of a cell wall 
D)  water moving out of the cell 
E)  the presence of chloroplasts 
A)  plasma membrane 
B)  transport proteins, which help pump the excess water out of the cell 
C)  the presence of a cell wall 
D)  water moving out of the cell 
E)  the presence of chloroplasts

Question 15

Which of the following is an example of potential energy rather than kinetic energy?

Accepted Answer

A)  an apple made up of energy-rich macromolecules 
B)  a firefly using light flashes to attract a mate 
C)  a skier at the bottom of the hill instead of the top of the hill 
D)  a pile of leaves that have been burnt 
E)  a candle giving off light 
A)  an apple made up of energy-rich macromolecules 
B)  a firefly using light flashes to attract a mate 
C)  a skier at the bottom of the hill instead of the top of the hill 
D)  a pile of leaves that have been burnt 
E)  a candle giving off light

Question 16

A white blood cell surrounds and engulfs a worn-out red blood cell. This process is called

Accepted Answer

A)  active transport. 
B)  phagocytosis. 
C)  exocytosis. 
D)  pinocytosis. 
E)  facilitated diffusion. 
A)  active transport. 
B)  phagocytosis. 
C)  exocytosis. 
D)  pinocytosis. 
E)  facilitated diffusion.

Question 17

Which of the following is a mechanism used to regulate enzyme activity?

Accepted Answer

A)  osmosis 
B)  facilitated diffusion 
C)  active transport 
D)  feedback inhibition 
E)  phagocytosis 
A)  osmosis 
B)  facilitated diffusion 
C)  active transport 
D)  feedback inhibition 
E)  phagocytosis

Question 18

The opposite of a turgid plant cell is a

Accepted Answer

A)  hypertonic plant cell. 
B)  osmotic plant cell. 
C)  isotonic plant cell. 
D)  plasmolyzed plant cell. 
E)  ruptured plant cell. 
A)  hypertonic plant cell. 
B)  osmotic plant cell. 
C)  isotonic plant cell. 
D)  plasmolyzed plant cell. 
E)  ruptured plant cell.

Question 19

When neurons release their neurotransmitters, they release them in secretory vesicles that fuse with the plasma membrane. What type of cellular transport is this?

Accepted Answer

A)  active transport 
B)  diffusion 
C)  exocytosis 
D)  pinocytosis 
E)  osmosis 
A)  active transport 
B)  diffusion 
C)  exocytosis 
D)  pinocytosis 
E)  osmosis

Question 20

ATP releases energy when

Accepted Answer

A)  a ribose is added. 
B)  adenine is removed. 
C)  a phosphate is removed. 
D)  deoxyribose is added. 
E)  sunlight strikes it. 
A)  a ribose is added. 
B)  adenine is removed. 
C)  a phosphate is removed. 
D)  deoxyribose is added. 
E)  sunlight strikes it.

Exam 5: The Dynamic Cell

Why do metabolic pathways require tens to hundreds of different enzymes?

Which of the following statements correctly describes an energy transformation in living organisms?

Which one of the following molecules is able to move across the cell membrane by simple diffusion?

Which of the following is best associated with a coupled reaction?

Molecules move from greater to lesser concentration through a carrier protein in

Which statement most accurately describes the second law of thermodynamics?

Considering the ATP cycle, which of the following would have the most potential energy to perform work for cell activities?

If blood cells are placed in a hypertonic solution, the cells will

The concentration of calcium in a cell is 3%. The concentration of calcium in the surrounding fluid is 1%. Which of the following processes could the cell use to obtain more calcium?

During an osmosis experiment, you place some plant cells under the microscope. You notice the cells seem very swollen. What type of solution were the cells immersed in?

The part of the enzyme into which the substrate fits is called the

Less energy is needed to bring about a reaction when an enzyme is present.

What prevents a plant cell from bursting in a hypotonic solution?

Which of the following is an example of potential energy rather than kinetic energy?

A white blood cell surrounds and engulfs a worn-out red blood cell. This process is called

Which of the following is a mechanism used to regulate enzyme activity?

The opposite of a turgid plant cell is a

When neurons release their neurotransmitters, they release them in secretory vesicles that fuse with the plasma membrane. What type of cellular transport is this?

ATP releases energy when

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