Question 1

Which of the following statements regarding active transport is false?

Accepted Answer

A)  Active transport uses ATP as an energy source.
B)  Active transport can move a solute against its concentration gradient.
C)  Active transport requires the cell to expend energy.
D)  Active transport is driven by the concentration gradient.E) A) and C)
F) B) and C)

Question 2

Most of the functions of a cell membrane, including transport and enzymatic function, are performed by

Accepted Answer

A)  glycolipids.
B)  proteins.
C)  phospholipids.
D)  cholesterol.E) A) and B)
F) All of the above

Question 3

Glucose molecules provide energy to power the swimming motion of sperm. In this example, the sperm are changing

Accepted Answer

A)  chemical energy into kinetic energy.
B)  chemical energy into potential energy.
C)  kinetic energy into potential energy.
D)  kinetic energy into thermal energy.E) A) and D)
F) A) and C)

Question 4

Osmosis can be defined as

Accepted Answer

A)  the diffusion of water.
B)  the diffusion of nonpolar molecules.
C)  active transport.
D)  the diffusion of a solute.E) C) and D)
F) A) and B)

Question 5

All cells are enclosed by a plasma membrane that is similar in ________ and ________.

Accepted Answer

A)  thickness; composition
B)  permeability; content
C)  lucidity; texture
D)  structure; functionE) A) and D)
F) A) and B)

Question 6

Small, nonpolar, hydrophobic molecules such as fatty acids

Accepted Answer

A)  easily pass through a membrane's lipid bilayer.
B)  very slowly diffuse through a membrane's lipid bilayer.
C)  require transport proteins to pass through a membrane's lipid bilayer.
D)  are actively transported across cell membranes.E) All of the above
F) A) and D)

Question 7

Aspirin and other nonsteroidal anti-inflammatory drugs (NSAID) inhibit inflammation by inhibiting an enzyme in the prostaglandin pathway, but by inhibiting this enzyme and this pathway they also inhibit pathways that protect the stomach from damage by stomach acid and that prevent aggregation of blood platelets to form blood clots. What can you conclude from this?

Accepted Answer

A)  The enzyme inhibition is nonreversible.
B)  The enzyme is found in many different types of cells.
C)  Prostaglandins cause blood clotting.
D)  Aspirin should not be given to people who people who need to synthesize enzymes.E) A) and B)
F) A) and C)

Question 8

Bacterial production of the enzymes needed for the synthesis of the amino acid tryptophan declines with increasing levels of tryptophan and increases as tryptophan levels decline. This is an example of

Accepted Answer

A)  competitive inhibition.
B)  noncompetitive inhibition.
C)  feedback inhibition.
D)  irreversible inhibition.E) All of the above
F) C) and D)

Question 9

Inhibition of an enzyme is irreversible when

Accepted Answer

A)  a competitive inhibitor is involved.
B)  a noncompetitive inhibitor is involved.
C)  the shape of the enzyme is changed.
D)  covalent bonds form between inhibitor and enzyme.E) A) and B)
F) A) and C)

Question 10

Cells acquire low-density lipoproteins (LDLs) by

Accepted Answer

A)  diffusion.
B)  receptor-mediated endocytosis.
C)  pinocytosis.
D)  phagocytosis.E) None of the above
F) A) and D)

Question 11

The process of a white blood cell engulfing a bacterium is

Accepted Answer

A)  osmosis.
B)  receptor-mediated endocytosis.
C)  pinocytosis.
D)  phagocytosis.E) B) and C)
F) A) and C)

Question 12

A cell that has neither a net gain of water nor net loss of water when it is immersed in a solution must be

Accepted Answer

A)  isotonic to its environment.
B)  hypertonic to its environment.
C)  hypotonic to its environment.
D)  metabolically inactive.E) B) and C)
F) A) and D)

Question 13

Which of the following substances could be a cofactor?

Accepted Answer

A)  a protein
B)  a polypeptide
C)  a zinc atom
D)  a ribosomeE) A) and C)
F) B) and C)

Question 14

Which of the following statements regarding membrane protein function is false?

Accepted Answer

A)  Membrane proteins serve as enzymes.
B)  Membrane proteins act as receptors to molecules like hormones.
C)  Membrane proteins form junctions between cells.
D)  Membrane proteins transfer genetic information to the cytoplasm.E) A) and B)
F) A) and C)

Question 15

Which of the following statements regarding thermodynamics is false?

Accepted Answer

A)  Thermodynamics is the study of energy transformations that occur in a collection of matter.
B)  A single cell or the planet Earth could be a thermodynamic system.
C)  An open system exchanges both energy and matter with its surroundings.
D)  An automobile engine is a closed system because it does not exchange energy and matter with its surroundings.E) C) and D)
F) None of the above

Question 16

Which of the following is a coenzyme?

Accepted Answer

A)  zinc
B)  vitamin B₆
C)  iron
D)  iodineE) None of the above
F) A) and D)

Question 17

Which of the following substances would have the most trouble crossing a biological membrane by diffusing through the lipid bilayer?

Accepted Answer

A)  O₂
B)  CO₂
C)  Na⁺
D)  a small, nonpolar molecule such as butane (C₄H₁₀) E) None of the above
F) C) and D)

Question 18

The fluid mosaic model describes the plasma membrane as consisting of

Accepted Answer

A)  a phospholipid bilayer with embedded carbohydrates.
B)  two layers of phospholipids with cholesterol sandwiched between them.
C)  carbohydrates and phospholipids that can drift in the membrane.
D)  diverse proteins embedded in a phospholipid bilayer.E) C) and D)
F) All of the above

Question 19

If you were working for a pharmaceutical company as part of a drug discovery team, which of these enzyme inhibitors would you suggest as a productive avenue for drug development?

Accepted Answer

A)  a drug to treat high blood pressure that reversibly inhibits an enzyme catalyzing production of a chemical that causes blood vessels to contract
B)  a drug to treat diabetes that irreversibly inhibits an enzyme in the metabolic pathway to synthesize glucose
C)  a compound that acts as a competitive inhibitor for a digestive enzyme produced only in the presence of certain foods
D)  a compound that inhibits enzymes by significantly changing the pH throughout the bodyE) None of the above
F) B) and C)

Question 20

In the lab, you use a special balloon that is permeable to water but not sucrose to make an "artificial cell." The balloon is filled with a solution of 20% sucrose and 80% water and is immersed in a beaker containing a solution of 40% sucrose and 60% water. The solution in the balloon is ________ relative to the solution in the beaker.

Accepted Answer

A)  isotonic
B)  hypotonic
C)  hypertonic
D)  hydrophilicE) All of the above
F) C) and D)

Exam 5: The Working Cell

Which of the following statements regarding active transport is false?

Correct Answer
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Which of the following substances could be a cofactor?

Correct Answer
verified

Small, nonpolar, hydrophobic molecules such as fatty acids

Correct Answer
verified

Inhibition of an enzyme is irreversible when

Correct Answer
verified

Most of the functions of a cell membrane, including transport and enzymatic function, are performed by

Correct Answer
verified

Which of the following is a coenzyme?

Correct Answer
verified

Which of the following statements regarding thermodynamics is false?

Correct Answer
verified

Osmosis can be defined as

Correct Answer
verified

Correct Answer
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Cells acquire low-density lipoproteins (LDLs) by

Correct Answer
verified

Which of the following statements regarding membrane protein function is false?

Correct Answer
verified

Bacterial production of the enzymes needed for the synthesis of the amino acid tryptophan declines with increasing levels of tryptophan and increases as tryptophan levels decline. This is an example of

Correct Answer
verified

Correct Answer
verified

If you were working for a pharmaceutical company as part of a drug discovery team, which of these enzyme inhibitors would you suggest as a productive avenue for drug development?

Correct Answer
verified

The process of a white blood cell engulfing a bacterium is

Correct Answer
verified

The fluid mosaic model describes the plasma membrane as consisting of

Correct Answer
verified

A cell that has neither a net gain of water nor net loss of water when it is immersed in a solution must be

Correct Answer
verified

Glucose molecules provide energy to power the swimming motion of sperm. In this example, the sperm are changing

Correct Answer
verified

Which of the following substances would have the most trouble crossing a biological membrane by diffusing through the lipid bilayer?

Correct Answer
verified

All cells are enclosed by a plasma membrane that is similar in and .

Correct Answer
verified

Exam 5: The Working Cell

Which of the following statements regarding active transport is false?

Correct AnswerverifiedShow Answer

Which of the following substances could be a cofactor?

Correct AnswerverifiedShow Answer

Small, nonpolar, hydrophobic molecules such as fatty acids

Correct AnswerverifiedShow Answer

Inhibition of an enzyme is irreversible when

Correct AnswerverifiedShow Answer

Most of the functions of a cell membrane, including transport and enzymatic function, are performed by

Correct AnswerverifiedShow Answer

Which of the following is a coenzyme?

Correct AnswerverifiedShow Answer

Which of the following statements regarding thermodynamics is false?

Correct AnswerverifiedShow Answer

Osmosis can be defined as

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Cells acquire low-density lipoproteins (LDLs) by

Correct AnswerverifiedShow Answer

Which of the following statements regarding membrane protein function is false?

Correct AnswerverifiedShow Answer

Bacterial production of the enzymes needed for the synthesis of the amino acid tryptophan declines with increasing levels of tryptophan and increases as tryptophan levels decline. This is an example of

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

If you were working for a pharmaceutical company as part of a drug discovery team, which of these enzyme inhibitors would you suggest as a productive avenue for drug development?

Correct AnswerverifiedShow Answer

The process of a white blood cell engulfing a bacterium is

Correct AnswerverifiedShow Answer

The fluid mosaic model describes the plasma membrane as consisting of

Correct AnswerverifiedShow Answer

A cell that has neither a net gain of water nor net loss of water when it is immersed in a solution must be

Correct AnswerverifiedShow Answer

Glucose molecules provide energy to power the swimming motion of sperm. In this example, the sperm are changing

Correct AnswerverifiedShow Answer

Which of the following substances would have the most trouble crossing a biological membrane by diffusing through the lipid bilayer?

Correct AnswerverifiedShow Answer

All cells are enclosed by a plasma membrane that is similar in ________ and ________.

Correct AnswerverifiedShow Answer

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All cells are enclosed by a plasma membrane that is similar in and .

Correct Answer
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