Biology Chapter 5

When a person cries, tears are exported from cells through the process of ________. A) exocytosis B) active transport C) facilitated diffusion D) endocytosis

A) exocytosis

When molecules move down their concentration gradient, they move from where they are __________ to where they are __________

more concentrated; less concentrated.

Diffusion across a biological membrane is called __________.

passive transport

Which one of the following terms is sometimes called "cell eating"? A) pinocytosis B) plasmolysis C) phagocytosis D) exocytosis

B) Phagocytosis In phagocytosis, a cell engulfs a particle and packages it within a food vacuole.

Which one of the following is TRUE? A) Enzymes catalyze specific reactions. B) Enzymes are the reactants in a chemical reaction. C) Enzymes' functions require inhibitors. D) Enzymes are the products in a chemical reaction.

A) Enzymes catalyze specific reactions.

The use of energy to move molecules across a membrane defines __________. A) active transport B) pinocytosis C) phagocytosis D) passive transport

A) active transport Cellular energy is used to drive a transport protein that pumps a solute across a gradient

Substances that plug up an enzyme's active site are ________. A)enzyme catalysts B) enzyme products C) enzyme inhibitors D) enzyme substrates

C) enzyme inhibitors

Usually, enzymes are ________. A) fats B) steroids C) proteins D) chemical reactions

C) proteins

In active transport, A) the plasma membrane forms a pocket that pinches inward, forming a vesicle that contains material from outside the cell. B) no energy input is required from the cell. C) molecules move across the plasma membrane by crossing the lipid bilayer directly, rather than by using a transport protein. D) molecules move across the plasma membrane against their concentration gradient. E) a vesicle inside the cell fuses with the plasma membrane and releases its contents outside the cell.

D) molecules move across the plasma membrane against their concentration gradient.

An enzyme's function is most dependent on its ________. A) temperature B) pH C) size D) shape

D) shape

Mechanisms such as __________ enable precise control over a cell's __________ -- all of its chemical reactions.

Feedback inhibition Metabolism

There are three main types of cellular work: chemical, transport, and movement. Most of this work is powered by the transfer of a phosphate group from one molecule to another in a process known as _______________.

Phosphorylation

Which of the following is a measure of randomness in a system? a) entropy b)kinetic energy c)chemical energy d) potential energy

a) Entropy

An enzyme is specific because the shape of its __________ matches only particular reactants.

active site

Which one of the following statements about energy is correct? a) Chemical energy is a form of kinetic energy. b) Energy cannot be created or destroyed. c) A leaf falling from a tree represents potential energy. d) We convert about 99% of our food energy to useful work.

b) Energy cannot be created or destroyed.

A(n) __________ , which is often a vitamin, binds to an enzyme and plays a role in catalysis.

coenzyme

Entropy means that __________. a) life should be impossible b) energy can be neither created nor destroyed c) it is not possible to observe an increase in molecular organization d) the quantity of usable energy declines with each energy transformation

d) the quantity of usable energy declines with each energy transformation

High temperatures or changes in pH can __________ an enzyme, causing it to lose its shape and biological activity.

denature

The __________ between an active site and its substrate often strains bonds and helps the reaction proceed.

induced fit

Which of the following molecules spontaneously form membranes when mixed in water and most likely were one of the first organic compounds formed on Earth? a) DNA b) Enzymes c) Phospholipids d) RNA

c) Phospholipids

What compound directly provides energy for cellular work? A) sugar B) ATP C) DNA D fat

B) ATP

The plasma membrane forms a pocket that pinches inward, forming a vesicle that contains material from outside the cell

Endocytosis

A specific ___________ speeds up each of a cell's chemical reactions.

Enzyme

2. Through energy coupling, cells use___________ , or energy-releasing, reactions to drive__________ , or energy-requiring, reactions. The molecule ___________ is the energy shuttle between these two types of reactions.

Exergonic Endergonic ATP

A vesicle inside the cell fuses with the plasma membrane and releases its contents outisde the cell

Exocytosis

a form of passive transport. molecules movre across the plasma membrane using a transport.

Facilitated Diffusion

When cells are placed in hypotonic solutions, both animal and plant cells accumulate water as a result of osmosis. This causes the cells to swell. Why can plant cells better tolerate hypotonic solutions? A) Animal cells can burst in such situations. In plants, however, rigid cell walls limit how far cells can expand and exert a back pressure to limit further water uptake. B)Stomata in plant cell leaves quickly drain excess water from the cells. C) Sunlight causes plant cells to lose water through transpiration. D)Plants have contractile vacuoles that continually bail out excess water that enters plant cells.

A) Animal cells can burst in such situations. In plants, however, rigid cell walls limit how far cells can expand and exert a back pressure to limit further water uptake. You might compare this to blowing air into a balloon placed inside a jar

Molecules of food have a form of potential energy called __________. A) chemical energy B) ATP C) kinetic energy D) entropy

A) chemical energy

The region of an enzyme to which a substrate binds is called the ________ site. A) enzymatic B) substrate C) active D) inactive

C) active

Which is the best definition of energy? a) ATP b) the conversion of one form of chemical energy to another form of chemical energy c) the capacity to cause change d) the conversion of light energy to chemical energy

c) the capacity to cause change

Every time energy is converted from one form to another, __________. A) entropy increases B) the amount of energy in the universe increases C)the amount of energy in the universe decreases D) entropy decreases

A) entropy increases

Requires energy from the cell. molecules move agaisnt their concentration gradient.

Active Transport

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

A) exocytosis

A molecule moves down its concentration gradient using a transport protein in the plasma membrane. This is an example of A) facilitated diffusion. B) exocytosis. C) diffusion. D) active transport. E) endocytosis.

A) facilitated diffusion.

In osmosis, water always moves toward the __________ solution, that is, toward the solution with the __________ solute concentration. A) hypertonic ... greater B) hypotonic ... greater C) isotonic ... greater D) hypertonic ... lesser

A) hypertonic ... greater Water moves by osmosis from the hypotonic solution toward the hypertonic solution. If the solution were isotonic, both solutions would have the same solute concentration

You know that this cell is in a(n) _____ solution because it _____. A) hypertonic solution ... lost water B) hypertonic ... gained water C) hypotonic ... lysed D) hypotonic ... is turgid E) hypertonic ... lysed

A) hypertonic solution ... lost water

You know that this cell is in a(n) _____ solution because the cell _____. A) hypotonic ... swelled B) hypotonic ... shrunk C) isotonic ... neither lost nor gained water D) hypertonic ... lost water E) hypertonic ... gained water

A) hypotonic ... swelled

The sum total of all the chemical reactions that occur in organisms is called ________. A) metabolism B hydrolysis C) cellular synthesis D) conservation of energy

A) metabolism

Diffusion is an example of ________. A) passive transport B) endocytosis C) phagocytosis D) active transport

A) passive transport

Facilitated diffusion is a type of _____. A) passive transport B) pinocytosis C)active transport D) phagocytosis

A) passive transport

Energy is transferred from ATP to other molecules by transferring a(n) ________. A) phosphate group B) adenosine C) ADP D) heat unit

A) phosphate group

Most enzymes are _____. A) proteins B) nucleic acids C)carbohydrates D) lipids E) minerals

A) proteins

What name is given to the reactants in an enzymatically catalyzed reaction? A) substrate B) products C) reactors D) active sites

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)expulsion of water by the plant cell's central vacuole C)the relative impermeability of the plant cell wall to water D)the relative impermeability of the plant cell membrane to water

A)the relative inelasticity and strength of the plant cell wall

Which one of the following is TRUE? A) Enzymes work generally on a broad range of substrates. B) An enzyme's function depends on its three-dimensional shape. C) Enzymes are used up in chemical reactions. D) Enzymes emerge changed from the reactions they catalyze.

B) An enzyme's function depends on its three-dimensional shape.

Which one of the following is an example of osmosis? A) The smell of freshly baked pie spreads throughout a house. B) Water enters a plant by passing through the root cell membranes. C) Food in the refrigerator starts to taste like onions because the onions in the vegetable bin have been stored unwrapped. D)Potassium ions enter a red blood cell through the action of a specific ion transport protein.

B) Water enters a plant by passing through the root cell membranes. The passive transport of water across a selectively permeable membrane is called OSMOSIS

Which of these is exhibiting kinetic energy? A) the high-energy phosphate bonds of a molecule of ATP B) a space station orbiting Earth C) a rock on a mountain ledge D) an archer with a flexed bow E) a person sitting on a couch while watching TV

B) a space station orbiting Earth

The concentration of calcium in a cell is 0.3%. The concentration of calcium in the surrounding fluid is 0.1%. How could the cell obtain more calcium? A) diffusion B) active transport C) osmosis D) passive transport

B) active transport For the cell to accumulate calcium, it must move calcium against its concentration gradient. This process requires energy

In your body, what process converts the chemical energy found in glucose into the chemical energy found in ATP? A) redox B) cellular respiration C) digestion D) anabolism E) potentiation

B) cellular respiration

Activation energy can be described as __________. A) metabolism B) energy needed to activate the reactants and trigger a chemical reaction C) energy needed to activate an enzyme D) energy released by a chemical reaction

B) energy needed to activate the reactants and trigger a chemical reaction

How do some inhibitors slow down metabolic pathways when the products of the pathways are not needed but still allow a pathway to proceed when the products are needed? A) degrading enzyme molecules B) feedback regulation C) promoting an induced fit between a substrate and an enzyme's active site D) enzyme activation

B) feedback regulation

In cellular respiration, most energy is released and transferred to ATP when _____. A) high-energy C-C and C-H bonds in glucose are broken B) high-energy electrons "fall" to lower energy levels C) low-energy electrons are "raised" to higher energy levels D) low-energy C-H bonds in glucose are broken

B) high-energy electrons "fall" to lower energy levels

An enzyme _____. A) is a source of energy for endergonic reactions B) is an organic catalyst C) increases the the activation energy of a reaction D) can bind to nearly any molecule E) is a inorganic catalyst

B) is an organic catalyst

A cell that neither gains nor loses a net amount of water at equilibrium when it is immersed in a solution is ________. A) hypotonic to its environment B) isotonic to its environment C) hypertonic to its environment D) metabolically inactive

B) isotonic to its environment

Which of the following is highest in chemical energy? A) one molecule of ATP B) one molecule of glucose C) one molecule of CO2 D) one molecule of H2

B) one molecule of glucose

The act of a white blood cell engulfing a bacterium is ________. A) diffusion B) phagocytosis C) osmosis D) exocytosis

B) phagocytosis

Which component of the following reaction is the substrate? sucrose + sucrase + water → sucrase + glucose + fructose A) sucrase B) sucrose C) glucose D) fructose

B) sucrose

You can recognize the process of pinocytosis when _____. A) the cell is engulfing a large particle B)the cell is engulfing extracellular fluid C) a receptor protein is involved

B) the cell is engulfing extracellular fluid

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

B) transport proteins...down

An animal cell placed in a hypertonic solution will __________. A) lose water by active transport and shrivel B)lose water by osmosis and shrivel C) gain water by pinocytosis and lyse D)gain water by osmosis and lyse

B)lose water by osmosis and shrivel The hypertonic solution has a greater concentration of solutes. This causes water to diffuse out of the cell and shrivel

Cells use this molecule to store the chemical energy released by the breakdown of food molecules during cellular respiration. A) CO2 B) glucose C) ATP D) O2

C) ATP

Which of the following processes could result in the net movement of a substance into a cell, if the substance is more concentrated in the cell than in the surroundings? Which of the following processes could result in the net movement of a substance into a cell, if the substance is more concentrated in the cell than in the surroundings? A)facilitated diffusion B) diffusion C)active transport D)osmosis

C) active transport

Calories are units of __________. A) ATP B) entropy C) energy D) food mass

C) energy

"Conservation of energy" refers to the fact that _____. A) the net amount of disorder is always increasing B) the entropy of the universe is always increasing C) energy cannot be created or destroyed but can be converted from one form to another D) no chemical reaction is 100 percent efficient E) if you conserve energy you will not be as tired

C) energy cannot be created or destroyed but can be converted from one form to another

As a result of its involvement in a reaction, an enzyme _____. A)is used up B) loses energy C) is unchanged D) loses a phosphate group E) permanently alters its shape.

C) is unchanged

What name is given to the process by which water crosses a selectively permeable membrane? A) passive transport B) diffusion C) osmosis D) pinocytosis E) phagocytosis

C) osmosis

A white blood cell engulfing a bacterium is an example of _____. A) pinocytosis B) facilitated diffusion C) phagocytosis D) receptor-mediated endocytosis E) exocytosis

C) phagocytosis

Kinetic energy is energy in motion. Potential energy is _____ energy. A) solar B) electromagnetic C) stored D) heat

C) stored

Energy is conserved. This means that in any system, _____. A) high-quality energy input equals high-quality energy output B) light energy is released to replace the original input of solar energy C) total energy input equals total energy output D) energy is constantly recycled

C) total energy input equals total energy output

When two solutions that differ in solute concentration are placed on either side of a selectively permeable 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 lower solute concentration C)exhibit a net movement to the side with lower water concentration D)exhibit a net movement to the side with higher water concentration

C)exhibit a net movement to the side with lower water concentration

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 contains a higher B)concentration of solutes than the protozoan C)is hypotonic to the protozoan D)is hypertonic to the protozoan

C)is hypotonic to the protozoan

Water crosses the plasma membrane A) against its concentration gradient. B) through active transport. C) through cotransport. D) using a process that requires energy from the cell. E) through facilitated diffusion or diffusion.

E) through facilitated diffusion or diffusion.

What best explains the observation that enzymes are selective in the reactions they catalyze? A) What best explains the observation that enzymes are selective in the reactions they catalyze? The same enzyme can generally bind to many different types of substrate molecules. B) Active sites carry slight negative charges, and substrates tend to carry slight positive charges. C) Molecules and active sites vary in size; only properly sized molecules can fit. energy needed to activate the reactants and trigger a chemical reaction D) There is a precise compatibility between an enzyme's active site and the substrate molecule.

D) There is a precise compatibility between an enzyme's active site and the substrate molecule.

Active transport ________. A)can move solutes against their concentration gradient B) can involve the transport of ions C)uses ATP as an energy source D) all of the answer options

D) all of the answer options

The passive movement of molecules from an area of higher concentration to an area of lower concentration is called __________. A) endocytosis B) active transport C) phagocytosis D) diffusion

D) diffusion - molecules move down the concentration gradient

The plasma membrane forms a pocket that pinches inward, forming a vesicle that contains material from outside the cell. This describes the process of A) active transport. B) exocytosis. C) diffusion. D) endocytosis. E) passive transport.

D) endocytosis.

Which of these are by-products of cellular respiration? A) ATP and water B) water C) ATP D) heat and water E) glucose and water

D) heat and water

Endocytosis moves materials _____ a cell via _____. A) out of ... diffusion B) into ... a transport protein C) into ... facilitated diffusion D) into ... membranous vesicles E) out of ... membranous vesicles

D) into ... membranous vesicles

Enzymes work by _____. A) adding energy to a reaction B) decreasing the potential energy difference between reactant and product C) adding a phosphate group to a reactant D) reducing activation energy E) increasing the potential energy difference between reactant and product

D) reducing activation energy

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

D) result in cell death

Which component of the following reaction is the enzyme? sucrose + sucrase + water → sucrase + glucose + fructose A) glucose B) sucrose C) fructose D) sucrase

D) sucrase

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

D) the diffusion of water across a selectively permeable membrane

A balloon permeable to water but not to glucose contains a 10% glucose solution. A beaker contains a 5% glucose solution. Which of the following is TRUE? A)The solution in the beaker is hypertonic relative to the solution in the balloon. B)The solution in the balloon is hypotonic relative to the solution in the beaker. C)The solution in the balloon is isotonic; the solution in the beaker is hypertonic. D)The solution in the balloon is hypertonic relative to the solution in the beaker.

D)The solution in the balloon is hypertonic relative to the solution in the beaker.

In a hypotonic solution, a plant cell will ________. A)undergo plasmolysis B)burst C)become flaccid D)become turgid

D)become turgid

a form of passive traspaort. molecules move across the plasma membrane by crossing the lipid bilayer.

Diffusion

The sodium-potassium pump uses energy from ATP to move sodium ions out of the cell, and potassium ions into the cell. This is an example of A) exocytosis. B) diffusion. C) facilitated diffusion. D) passive transport. E) active transport.

E) active transport.

Chemical energy is a form of _____ energy. A) kinetic B) heat C) entropic D) motion E) potential

E) potential