Campbell Biology; Chapter 5: Worksheet

A major function of glycoproteins and glycolipids in the cell membrane is to A) attach the cell membrane to the cytoskeleton. B) allow the cells of an embryo to sort themselves into tissues and organs. C) glue cells together to form tissues. D) help the cell retain its shape.

allow the cells of an embryo to sort themselves into tissues and organs.

Which of the following is a coenzyme? A) iron B) zinc C) iodine D) vitamin B6

vitamin B6

The process of a white blood cell engulfing a bacterium is A) receptor-mediated endocytosis. B) pinocytosis. C) phagocytosis. D) osmosis.

phagocytosis.

Which of the following statements regarding active transport is false? A) Active transport requires the cell to expend energy. B) Active transport uses ATP as an energy source. C) Active transport is driven by the concentration gradient. D) Active transport can move a solute against its concentration gradient

Active transport is driven by the concentration gradient.

Which of the following statements regarding thermodynamics is false? 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.

An automobile engine is a closed system because it does not exchange energy and matter with its surroundings.

How does inhibition of an enzyme-catalyzed reaction by a competitive inhibitor differ from inhibition by a noncompetitive inhibitor? A) Competitive inhibitors bind to the enzyme reversibly; noncompetitive inhibitors bind to it irreversibly. B) Competitive inhibitors interfere with the enzyme; noncompetitive inhibitors interfere with the reactants. C) Competitive inhibitors bind to the active site of the enzyme; noncompetitive inhibitors bind to a different site. D) Competitive inhibitors change the enzyme's tertiary structure; noncompetitive inhibitors cause polypeptide subunits to dissociate.

Competitive inhibitors bind to the active site of the enzyme; noncompetitive inhibitors bind to a different site.

Which of the following statements regarding diffusion is false? A) Diffusion requires no input of energy into the system. B) Diffusion occurs when particles spread from areas where they are less concentrated to areas where they are more concentrated. C) Diffusion occurs even after equilibrium is reached and no net change is apparent. D) Diffusion is a result of the thermal energy of atoms and molecules.

Diffusion occurs when particles spread from areas where they are less concentrated to areas where they are more concentrated.

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

Membrane proteins transfer genetic information to the cytoplasm.

A child is brought to the hospital with a fever of 107°F. Doctors immediately order an ice bath to lower the child's temperature. Which of the following statements offers the most logical explanation for this action? A) Elevated body temperatures cause molecules to vibrate more quickly and prevent enzymes from easily attaching to reactants. This would slow vital body reactions. B) Elevated body temperatures may denature enzymes. This would interfere with the cell's abilities to catalyze various reactions. C) Elevated body temperatures will increase the energy of activation needed to start various chemical reactions in the body. This will interfere with the ability of enzymes to catalyze vital chemical reactions. D) Elevated body temperature will increase reaction rates in the child's cells and overload the limited number of enzymes found in the cell.

Elevated body temperatures may denature enzymes. This would interfere with the cell's abilities to catalyze various reactions.

Which of the following statements regarding enzyme function is false? A) An enzyme's function depends on its three-dimensional shape. B) Enzymes are used up when they catalyze a chemical reaction, so must be synthesized for each new chemical reaction. C) Enzymes emerge unchanged from the reactions they catalyze. D) Enzymes are very specific for certain substrates.

Enzymes are used up when they catalyze a chemical reaction, so must be synthesized for each new chemical reaction.

Which of the following statements regarding enzymes is true? A) All enzymes depend on protein cofactors to function. B) Enzymes catalyze specific reactions. C) An enzyme's function is unaffected by changes in pH. D) Enzymes are inorganic.

Enzymes catalyze specific reactions.

What is the basic difference between exergonic and endergonic reactions? A) In exergonic reactions, the reactants have less chemical energy than the products; in endergonic reactions, the opposite is true. B) Exergonic reactions release energy; endergonic reactions absorb it. C) Exergonic reactions involve the breaking of bonds; endergonic reactions involve the formation of bonds. D) Exergonic reactions involve ionic bonds; endergonic reactions involve covalent bonds.

Exergonic reactions release energy; endergonic reactions absorb it.

Which of the following statements about the ATP molecule is true? A) It contains five phosphate groups. B) It contains the sugar glucose. C) Extremely stable bonds link the second and third phosphate groups. D) It releases energy when one phosphate group leaves ATP.

It releases energy when one phosphate group leaves ATP.

White blood cells (WBCs) are more resistant to lysis than red blood cells (RBCs). When looking at a sample of blood for WBCs, what could you do to reduce interference from RBCs? A) Mix the blood in a salty solution to cause the RBCs to lyse. B) Mix the blood in a hypertonic solution, which will cause the RBCs to lyse. C) Mix the blood in an isotonic solution and allow the WBCs to float to the top. D) Mix the blood in a hypotonic solution, which will cause the RBCs to lyse.

Mix the blood in a hypotonic solution, which will cause the RBCs to lyse.

Which of the following substances would have the most trouble crossing a biological membrane by diffusing through the lipid bilayer? A) a small, nonpolar molecule such as butane (C4H10) B) CO2 C) Na+ D) O2

Na+

Which of the following statements is true among all types of passive transport? A) Ions never cross the plasma membrane by passive transport. B) The concentration gradient is the driving force. C) Proteins are needed to transport molecules across the membrane. D) Only small polar molecules are able to cross the plasma membrane.

The concentration gradient is the driving force.

Which of the following statements regarding membrane function is false? A) The plasma membrane forms a selective barrier around the cell. B) The plasma membrane is the control center of the cell. C) The plasma membrane plays a role in signal transduction. D) The plasma membrane has receptors for chemical messages.

The plasma membrane is the control center of the cell.

Which of the following is a typical feature of an ATP-driven active transport mechanism? A) The transport protein is irreversibly phosphorylated as transport takes place. B) The transport protein must cross to the correct side of the membrane before the solute can bind to it. C) The solute moves against the concentration gradient. D) The transport protein catalyzes the conversion of ADP to ATP.

The solute moves against the concentration gradient.

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. Which of the following will occur? A) Sucrose will enter the balloon. B) Sucrose will leave the balloon. C) Water will enter the balloon. D) Water will leave the balloon.

Water will leave the balloon.

Which of the following substances could be a cofactor? A) a ribosome B) a polypeptide C) a protein D) a zinc atom

a zinc atom

Substrates bind to an enzyme's ________ site. A) phosphate B) inhibitory C) allosteric D) active

active

Which of the following processes can move a solute against its concentration gradient? A) active transport B) passive transport C) facilitated diffusion D) osmosis

active transport

Aquaporins A) allow for the active transport of water. B) allow water to cross the plasma membrane against its concentration gradient. C) allow water to cross the plasma membrane via facilitated diffusion. D) are found in all cells.

allow water to cross the plasma membrane via facilitated diffusion.

Membrane phospholipids A) have hydrophilic tails that face outward and are exposed to water. B) remain fluid because they are tightly packed against one another. C) have hydrophobic heads that face the center of the membrane and are shielded from water. D) are able to drift about in the plasma membrane

are able to drift about in the plasma membrane

A plant cell in a hypotonic solution A) wilts because of an outflow of water. B) shrivels because of an outflow of water. C) becomes turgid because of an inflow of water. D) bursts because of an inflow of water

becomes turgid because of an inflow of water.

When physicians perform an organ transplant, they choose a donor whose tissues match those of the recipient as closely as possible. Which of the following cell components are being matched? A) plasma membrane cholesterols B) plasma membrane proteins C) plasma membrane phospholipids D) cell-surface carbohydrates

cell-surface carbohydrates

Heating inactivates enzymes by A) changing the enzyme's three-dimensional shape. B) breaking the covalent bonds that hold the molecule together. C) removing phosphate groups from the enzyme. D) causing enzyme molecules to stick together.

changing the enzyme's three-dimensional shape.

Glucose molecules provide energy to power the swimming motion of sperm. In this example, the sperm are changing A) kinetic energy into thermal energy. B) chemical energy into kinetic energy. C) kinetic energy into potential energy. D) chemical energy into potential energy.

chemical energy into kinetic energy.

Inhibition of an enzyme is irreversible when A) a competitive inhibitor is involved. B) the shape of the enzyme is changed. C) covalent bonds form between inhibitor and enzyme. D) a noncompetitive inhibitor is involved.

covalent bonds form between inhibitor and enzyme.

Living systems A) are examples of a closed system. B) violate the first law of thermodynamics. C) decrease their entropy while increasing the entropy of the universe. D) violate the second law of thermodynamics

decrease their entropy while increasing the entropy of the universe.

The fluid mosaic model describes the plasma membrane as consisting of A) two layers of phospholipids with cholesterol sandwiched between them. B) carbohydrates and phospholipids that can drift in the membrane. C) a phospholipid bilayer with embedded carbohydrates. D) diverse proteins embedded in a phospholipid bilayer.

diverse proteins embedded in a phospholipid bilayer.

Phagocytosis is to eating as pinocytosis is to A) chewing. B) drinking. C) osmosis. D) lysis.

drinking.

Small, nonpolar, hydrophobic molecules such as fatty acids A) are actively transported across cell membranes. B) require transport proteins to pass through a membrane's lipid bilayer. C) easily pass through a membrane's lipid bilayer. D) very slowly diffuse through a membrane's lipid bilayer.

easily pass through a membrane's lipid bilayer.

ATP can be used as the cell's energy exchange mechanism because A) ATP is the most energy-rich small molecule in the cell. B) endergonic reactions can be fueled by coupling them with the hydrolysis of high-energy phosphate bonds in ATP. C) endergonic reactions can be fueled by coupling them with the formation of ATP from ADP. D) ATP is a disposable form of chemical energy, used once and then discarded by the cell.

endergonic reactions can be fueled by coupling them with the hydrolysis of high-energy phosphate bonds in ATP.

When a cell uses chemical energy to perform work, it uses the energy released from a(n) ________ reaction to drive a(n) ________ reaction. A) exergonic . . . endergonic B) endergonic . . . exergonic C) spontaneous . . . exergonic D) exergonic . . . spontaneous

exergonic . . . endergonic

When two aqueous solutions that differ in solute concentration are placed on either side of a semipermeable membrane and osmosis is allowed to take place, the water will A) exhibit an equal movement in both directions across the membrane. B) exhibit a net movement to the side with higher free water concentration. C) exhibit a net movement to the side with lower free water concentration. D) exhibit a net movement to the side with lower solute concentration.

exhibit a net movement to the side with lower free water concentration.

Certain cells that line the stomach synthesize a digestive enzyme and secrete it into the stomach. This enzyme is a protein. Which of the following processes could be responsible for its secretion? A) diffusion B) endocytosis C) pinocytosis D) exocytosis

exocytosis

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 A) irreversible inhibition. B) noncompetitive inhibition. C) feedback inhibition. D) competitive inhibition

feedback inhibition.

Which of the following energy transfers is impossible in living systems? A) light energy to potential energy B) light energy to chemical energy C) heat to light energy D) chemical energy to kinetic energy

heat to light energy

The cholesterol associated with animal cell membranes A) is attached to membrane proteins and extends into the watery environment surrounding the cell. B) is an abnormality resulting from a diet high in cholesterol. C) helps solidify the membranes when the room temperature is below freezing. D) helps to stabilize the cell membrane at body temperature.

helps to stabilize the cell membrane at body temperature.

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. A) hypertonic B) hydrophilic C) isotonic D) hypotonic

hypotonic

Many of the enzymes that control a deep-sea firefly squid's ability to produce light energy from chemical energy are located A) in membranes. B) outside of cells. C) within mitochondria. D) within chloroplasts.

in membranes.

Some protozoans have special organelles called contractile vacuoles that continually eliminate excess water from the cell. The presence of these organelles tells you that the environment A) is isotonic to the protozoan. B) is hypertonic to the protozoan. C) contains a higher concentration of solutes than the protozoan. D) is hypotonic to the protozoan.

is hypotonic to the protozoan.

A cell that neither gains nor loses water when it is immersed in a solution must be A) hypertonic to its environment. B) metabolically inactive. C) isotonic to its environment. D) hypotonic to its environment.

isotonic to its environment.

When an enzyme catalyzes a reaction, A) it raises the activation energy of the reaction. B) it lowers the activation energy of the reaction. C) it acts as a reactant. D) it is used once and discarded.

it lowers the activation energy of the reaction.

Kinetic energy differs from chemical energy in that A) kinetic energy can be converted into various forms of energy, whereas chemical energy can only be converted into heat. B) chemical energy is a particular form of kinetic energy. C) kinetic energy is stored energy that has the potential to do work, and chemical energy is the energy of movement. D) kinetic energy is the energy of a moving object, whereas chemical energy is the potential energy of molecules.

kinetic energy is the energy of a moving object, whereas chemical energy is the potential energy of molecules.

In a hypotonic solution, an animal cell will A) shrivel. B) neither gain nor lose water. C) experience turgor. D) lyse.

lyse.

Diffusion does not require the cell to expend ATP. Therefore, diffusion is considered a type of A) endocytosis. B) exocytosis. C) passive transport. D) active transport.

passive transport.

Oxygen crosses a plasma membrane by A) passive transport. B) active transport. C) pinocytosis. D) osmosis.

passive transport.

The transfer of a phosphate group to a molecule or compound is called A) carboxylation. B) hydrogenation. C) phosphorylation. D) ionization.

phosphorylation.

An energy barrier A) is higher than the activation energy of a reaction. B) can only be overcome with the use of enzymes. C) prevents the spontaneous breakdown of molecules in the cell. D) is the amount of energy that must be produced by the reactants to end a chemical reaction

prevents the spontaneous breakdown of molecules in the cell.

Which of the following examples is classified as a metabolic pathway? A) protein synthesis B) osmosis C) passive diffusion D) cell lysis

protein synthesis

Most of a cell's enzymes are A) proteins. B) amino acids. C) lipids. D) carbohydrates.

proteins.

Most of the functions of a cell membrane, including transport and enzymatic function, are performed by A) proteins. B) phospholipids. C) glycolipids. D) cholesterol.

proteins.

The molecules responsible for membrane transport are A) carbohydrates. B) phospholipids. C) steroids. D) proteins.

proteins.

Cells acquire LDLs by A) pinocytosis. B) receptor-mediated endocytosis. C) diffusion. D) phagocytosis.

receptor-mediated endocytosis.

Anything that prevents ATP formation will most likely A) result in cell death. B) have no effect on the cell. C) force the cell to rely on lipids for energy. D) force the cell to rely on ADP for energy.

result in cell death.

Which characteristic promoted the utilization of lipids as the first cell membrane? A) formation of a semi-solid membrane B) spontaneous degradation of the intracellular environment C) self-assembly into a simple membrane D) ability to form an impermeable membrane

self-assembly into a simple membrane

Relaying a message from a membrane receptor to a molecule that performs a specific function within a cell is called A) selective permeability. B) competition. C) inhibition. D) signal transduction.

signal transduction.

All cells are enclosed by a plasma membrane that is similar in ________ and ________. A) thickness . . . composition B) permeability . . . content C) structure . . . function D) lucidity . . . texture

structure . . . function

The energy required to initiate an exergonic reaction is called A) the activation energy. B) endergonic energy. C) input energy. D) exergonic energy.

the activation energy.

Osmosis can be defined as A) active transport. B) the diffusion of water. C) the diffusion of nonpolar molecules. D) the diffusion of a solute.

the diffusion of water.

According to ________, energy cannot be created or destroyed. A) Aristotle's first principle B) the second law of thermodynamics C) the third law of thermodynamics D) the first law of thermodynamics

the first law of thermodynamics

Plasma membranes are selectively permeable. This means that A) glucose cannot enter the cell. B) plasma membranes must be very thick. C) anything can pass into or out of a cell as long as the membrane is intact and the cell is healthy. D) the plasma membrane allows some substances to enter or leave a cell more easily than others.

the plasma membrane allows some substances to enter or leave a cell more easily than others.

In the reaction A B + C + heat, A) the potential energy of the products is less than that of the reactant. B) the potential energy of the products is greater than that of the reactant. C) there is a net input of energy. D) entropy has decreased.

the potential energy of the products is less than that of the reactant.

The active site of an enzyme is A) the region of a product that detaches from the enzyme. B) the region of a substrate that is changed by an enzyme. C) the region of an enzyme that attaches to a substrate. D) the highly changeable portion of an enzyme that adapts to fit the substrates of various reactions.

the region of an enzyme that attaches to a substrate.

If placed in tap water, an animal cell will undergo lysis, whereas a plant cell will not. What accounts for this difference? A) the relative inelasticity and strength of the plant cell wall B) the fact that plant cells are isotonic to tap water C) the relative impermeability of the plant cell wall to water D) the expulsion of water by the plant cell's central vacuole

the relative inelasticity and strength of the plant cell wall

A steer must eat at least 100 pounds of grain to gain less than 10 pounds of muscle tissue. This illustrates A) the first law of thermodynamics. B) the second law of thermodynamics. C) that energy transformations are typically 100% efficient. D) that some energy is destroyed in every energy conversion.

the second law of thermodynamics.

Which of the following processes is endergonic? A) cellular respiration B) the breakdown of glucose C) the burning of wood D) the synthesis of glucose from carbon dioxide and water

the synthesis of glucose from carbon dioxide and water

Facilitated diffusion across a biological membrane requires ________ and moves a substance ________ its concentration gradient. A) energy and transport proteins . . . down B) transport proteins . . . down C) energy and transport proteins . . . against D) transport proteins . . . against

transport proteins . . . down

You are adrift in the Atlantic Ocean, and, being thirsty, drink the surrounding seawater. As a result, A) you dehydrate yourself. B) you quench your thirst. C) your cells lyse from excessive water intake. D) your cells become turgid.

you dehydrate yourself.