Mastering Biology Chapter 8

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 glucose sugar

ATP

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

Cellular Respiration

A _________, such as a vitamin, binds to an enzyme and plays a role in catalysis.

Cofactor

A _____________ inhibitor has a structure that is so similar to the substrate that it can bond to the enzyme just like the substrate.

Competitive

When properly aligned, the enzyme and substrate form an enzyme-substrate (ES)________.

Complex

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

Exergonic.......uphill

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

Heat, carbon dioxide, and water

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

Hydrolysis

Prefix, suffixes, and word roots with their definitions: moving

-kin (or -kinet)

Prefix, suffixes, and word roots with their definitions: milk

-lac (or -lact)

Prefix, suffixes, and word roots with their definitions: under, below

-sub

Prefix, suffixes, and word roots with their definitions: heat

-therm

Prefix, suffixes, and word roots with their definitions: across

-trans

Prefix, suffixes, and word roots with their definitions: Change, turn, move

-trop

Prefix, suffixes, and word roots with their definitions: other

-alto

Prefix, suffixes, and word roots with their definitions: enzyme

-ase

Prefix,suffixes, and word roots with their definitions: Outside of

-extra

Prefix, suffixes, and word roots with their definitions: sweet

-glyc

Which of the following statements about equilibrium of chemical reactions is correct? A reaction that is at equilibrium is not capable of doing any work. Reactions can only go in the direction toward equilibrium. Most reactions in a living cell are close to equilibrium. The equilibrium point is where the system has the highest free energy The equilibrium point of a reaction represents the least stable configuration for that reaction.

A reaction that is at equilibrium is not capable of doing any work

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

A space station orbiting Earth

A substrate binds to an enzyme at the _________, where the reaction occurs

Active site

The competitive inhibitor competes with the substrate for the ___________ on the enzyme.

Active site

You have an enzymatic reaction proceeding at the optimum pH and optimum temperature. You add a competitive inhibitor to the reaction and notice that the reaction slows down. What can you do to speed the reaction up again? Add more inhibitor to speed up the reaction. Add more substrate; it will outcompete the inhibitor and increase the reaction rate. Increase the temperature. Increase the pH.

Add more substrate; it will outcompete the inhibitor and increase the reaction rate

An enzyme is considered a ___________because it speeds up chemical reactions without being used up.

Catalyst

An enzyme is ___________when it loses its native conformation and its biological activity.

Denatured

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

Endergonic

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

Endergonic

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

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

When the noncompetitive inhibitor is bonded to the enzyme, the shape of the __________ is distorted.

Enzyme

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

Exergonic

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

Exergonic

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

Exergonic

Usually, a(n) __________ inhibitor forms a covalent bond with an amino acid side group within the active site, which prevents the substrate from entering the active site or prevents catalytic activity.

Irreversible

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

It is acquired by a reactant in an endergonic reaction

A ______________ inhibitor binds to a site on the enzyme that is not the active site.

Noncompetitive

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

Potential

An enzyme is considered __________because of its ability to recognize the shape of a particular molecule.

Specific

Enzyme inhibitors disrupt normal interactions between an enzyme and its ___________

Substrate

In a catalyzed reaction a reactant is often called a ________

Substrate

Which of the following statements about the combustion of glucose with oxygen to form water and carbon dioxide (C6H12O6 + 6 O2 → 6 CO2 + 6 H2O) is correct? The entropy of the universe decreases as the result of this reaction. This is the process of cellular respiration, an anabolic pathway that releases free energy. The entropy of the products is greater than the entropy of the reactants. The reverse reaction, making glucose from water and carbon dioxide, must be an exergonic reaction. The free energy lost in this combustion is less than the energy that appears as heat.

The entropy of the products is greater than the entropy of the reactants

You have added an irreversible inhibitor to a sample of enzyme and substrate. At this point, the reaction has stopped completely.What can you do to regain the activity of the enzyme? Removing the irreversible inhibitor should get the reaction working again. The enzyme is inactive at this point. New enzyme must be added to regain enzyme activity. Adding more substrate will increase the rate of reaction. Adding more inhibitor should get the reaction up to speed again.

The enzyme is inactive at this point. New enzyme must be added to regain enzyme activity

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

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