Biology Mastering CH 5

A(n) _______, which is often a vitamin, binds to an enzyme and okays a role in catalysis

coenzyme

Which of these are by-products of cellular respiration? glucose and water water ATP and water ATP heat and water

heat and water

Chemical energy is a form of _____ energy. motion potential heat entropic kinetic

potential

An energy barrier prevents the spontaneous breakdown of molecules in the cell. can only be overcome with the use of enzymes. is higher than the activation energy of a reaction. 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.

Most enzymes are _____. lipids minerals proteins nucleic acids carbohydrates

proteins

In cells, what is usually the immediate source of energy for an endergonic reaction? ATP ADP as spontaneous reactions, endergonic reactions do not need an addition of energy sugar glucose

ATP

Which of the following is an accurate comparison of active transport and facilitated diffusion? In both types of movement, phosphate groups alter the shape of transport proteins. Active transport requires membrane proteins; facilitated diffusion does not require membrane proteins. Facilitated diffusion requires the use of ATP; active transport does not require ATP. Active transport moves solutes against their concentration gradient; facilitated diffusion moves substances down their concentration gradient.

Active transport moves solutes against their concentration gradient; facilitated diffusion moves substances down their concentration gradient.

What is the fate of the phosphate group that is removed when ATP is converted to ADP? It is acquired by a reactant in an exergonic reaction. It is acquired by a reactant in a spontaneous reaction. It is used to convert an ATP into an AQP. It is acquired by a reactant in an endergonic reaction. It is broken down into one phosphorus and four oxygen atoms.

It is acquired by a reactant in an endergonic reaction.

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

It releases energy when one phosphate group leaves ATP.

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

The solute moves against the concentration gradient.

The concentration of solutes in a red blood cell is about 2%. Sucrose cannot pass through the membrane, but water and urea can. Osmosis would cause red blood cells to shrink the most when immersed in which of the following solutions? a hypotonic sucrose solution a hypertonic sucrose solution a hypotonic urea solution a hypertonic urea solution

a hypertonic sucrose solution

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

a space station orbiting Earth

An enzyme speeds up reactions by lowering the _________

activation energy

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

active site

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 diffusion. facilitated diffusion. exocytosis. active transport. passive transport.

active transport.

Utah's Great Salt Lake has an average salinity seven times higher than that of the oceans. Very few multicellular organisms live in this harsh environment. An example is the brine shrimp, which must devote a large portion of its metabolic energy to osmoregulation. These brine shrimp must _____. actively pump salt back out of their cells to counter its inflow due to osmosis actively pump water back into their cells to counter its loss due to osmosis actively pump water back out of their cells to counter its inflow due to osmosis synthesize membranes that are impermeable to substances that upset osmotic balance

actively pump water back into their cells to counter its loss due to osmosis

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

are able to drift about in the plasma membrane.

An enzyme is considered a(n) _____ because it speeds up a chemical reaction without being used up

catalyst

In your body, what process converts the chemical energy found in glucose into the chemical energy found in ATP? digestion anabolism cellular respiration potentiation redox

cellular respiration

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

denature

The reaction ADP + P --> ATP is a(n) _____ reaction. hydrolysis chemical endergonic spontaneous exergonic

endergonic

Which of these reactions requires a net input of energy from its surroundings? endergonic exergonic ATP --> ADP + P hydrolysis catabolic

endergonic

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

endocytosis.

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

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

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

enzyme

A(n) _____ reaction occurs spontaneously. endergonic chemical kinetic anabolic exergonic

exergonic

The energy for an endergonic reaction comes from a(n) _____ reaction. glucose + glucose --> maltose exergonic ADP + P --> ATP anabolic synthesis

exergonic

The reaction A --> B + C + heat is released in a(n) _____ reaction. endergonic dehydration synthesis exergonic anabolic exchange

exergonic

Through energy coupling, cell 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

Select the INCORRECT association. kinetic energy ... motion enzyme ... protein potential energy ... positional energy exergonic ... spontaneous exergonic ... uphill

exergonic ... uphill

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

facilitated diffusion.

Mechanisms such as _____ able precise control over a cell's _______ -- all of its chemical reactions.

feedback inhibition Metabolism

What type of reaction breaks the bonds that join the phosphate groups in an ATP molecule? entropic hydrolysis anabolism dehydration synthesis dehydration decomposition

hydrolysis

A plant cell in a(n) ______ solution will lose water ad plasmolyze

hypertonic

There is a net diffusion of water out of an animal cell when it is placed in a(n) _____ solution.

hypertonic

An animal cell placed is a(n) ________ solution will gain water, swell, and possibly burst.

hypotonic

The ideal osmotic environment for a plant cell is a (n) _____ environment.

hypotonic

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

induced fit

Endocytosis moves materials _____ a cell via _____. into ... facilitated diffusion out of ... membranous vesicles into ... a transport protein out of ... diffusion into ... membranous vesicles

into ... membranous vesicles

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

is an organic catalyst

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

is unchanged

A plant cell surrounded by a(n) _____ solution will be flaccid (limp)

isotonic

The ideal osmotic environment for an animal cell is a(n) ______ environment

isotonic

Catalysts speed reactions mainly by ... providing activation energy. lowering EA. raising the kinetic energy of the reactants. increasing of activation energy barrier. None of the above.

lowering EA.

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

molecules move across the plasma membrane against their concentration gradient.

What name is given to the process by which water crosses a selectively permeable membrane? phagocytosis passive transport pinocytosis diffusion osmosis

osmosis

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

phagocytosis

There are three main types f 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

Enzymes work by _____. increasing the potential energy difference between reactant and product adding energy to a reaction adding a phosphate group to a reactant decreasing the potential energy difference between reactant and product reducing activation energy

reducing activation energy

In a catalyzed reaction, a reactant is often called a (n) ________

substrate

What name is given to the reactants in an enzymatically catalyzed reaction? active sites substrate products reactors

substrate

What is energy coupling? the use of an enzyme to reduce EA the hydrolysis of ATP to ADP + P a description of the energetic relationship between the reactants and products in an exergonic reaction a barrier to the initiation of a reaction the use of energy released from an exergonic reaction to drive an endergonic reaction

the use of energy released from an exergonic reaction to drive an endergonic reaction

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

through facilitated diffusion or diffusion.