Bio Unit 2 Chapter 4

Warmer temperatures generally ______ enzymatic activity, but when temperatures increase too much, enzymes denature

Speed up

The amount of energy required to start a reaction is called the _____ energy

activation

Chemical reactions occur faster when ______ is low

activation energy

The region where a substrate (reactant) binds to an enzyme is called the ______ site

active

The sodium-potassium pump requires about 25% of the cell's ATP because it conducts a type of membrane transport called _______ transport.

active

As shown in the diagram, the action of the sodium-potassium pump is a type of

active transport

What type of membrane transport is shown in the picture and requires ATP and a carrier molecule

active transport

What type of membrane transport requires energy (ATP) and transport proteins

active transport

ATP stands for ______ triphosphate, which is a molecule that powers many cellular reactions

adenosine

The ATP hydrolysis reaction shown in the image produces ______, a free phosphate group, and a burst of energy

adenosine diphosphate

The image shows a molecule of ______, which contains high-energy bonds between its phosphate groups

adenosine triphosphate

Facilitated diffusion of water occurs through proteins called ______, which increase the rate of water flow across a membrane

aquaporins

The gradient that drives the diffusion of oxygen into mitochondria is maintained by the

consumption of oxygen as soon as it enters mitochondria

An enzyme lowers the activation energy of a reaction by

bringing reactants into contact with each other

In diffusion, a substance moves

by passive transport to a region where the substance is less concentrated

The amount of energy required to raise the temperature of 1 g of water 1οC is equal to 1

calorie

Energy can be measured in units called

calories

At the end of a biochemical reaction, the enzyme

can be reused

Select all of the following that are functions of enzymes.

copy DNA recycle cell parts build molecules

In simultaneous ______ reactions, one reaction provides energy to drive another reaction

coupled

When ATP hydrolysis, an exergonic reaction, provides the energy for a simultaneous endergonic reaction, this is an example of _______ reactions.

coupled

Select all of the following that describe active transport

energy is required a substance moves against its concentration gradient transport proteins are required

The small "bump" indicated by the circle in the figure is the

energy required to get the reaction started

The laws of thermodynamics describe ______ in living and nonliving things

energy transformations

Living organisms are able to increase in complexity due to a constant input of ______ from the sun, but because the universe as a whole is also decreasing in complexity by a greater amount, the ______ in the universe is always increasing

energy; entropy

Particles that are too big for diffusion and active transport

enter and leave cells within vesicles

After a product is released from its active site, a(n) ______ can be used again in another reaction because it is not consumed or altered in the reaction

enzyme

What term is used to describe any nonprotein ion or organic molecule that aids an enzyme in catalyzing chemical reactions

cofactor

______ inhibition occurs when the product of a reaction binds to the active site of an enzyme and blocks the active site so that the enzyme cannot bind to the correct substrate

competitive

What process is occurring in the picture? (The purple structure is an enzyme and the square structure is a substrate.)

competitive inhibition

Aspirin is an example of a(n) ______ because it binds to and blocks an enzyme that produces pain-related prostaglandins

enzyme inhibitor

Catalyzing dehydration synthesis and oxidation-reduction reactions is a function of

enzymes

What is present in meat tenderizers to break down muscle tissue in meat to make it easier to chew

enzymes

What organic molecules catalyze (speed up) chemical reactions

enzymes

At equilibrium, molecules continue to move back and forth between areas of solution at ______ rates, creating ______ concentrations throughout a solution

equal; equal

Select all of the following that can act as enzyme cofactors

iron vitamin C zinc magnesium ions

In an isotonic solution, the solute concentration

is equal between two neighboring areas

ATP is used to drive endergonic reactions, and then ADP

is recycled back to ATP

If an equal amount of water enters and exits a human red blood cell, then the cell's interior is ______ to the cell's exterior

isotonic

A concentration ________ occurs when there are unequal amounts of a solute in neighboring regions

gradient

All energy eventually becomes ______ as it becomes more disordered

heat

Some of the energy released in all exergonic reactions is lost as ______, though some can be captured to power endergonic reactions

heat

The disordered energy produced by random movements of molecules is called

heat

What reaction releases a large amount of energy that the cell can use to do work

hydrolysis of ATP to form ADP

If a solution has a higher solute concentration than a cell, then the solution is ______ compared to the cell

hypertonic

If more water is exiting a human red blood cell than entering it, then the cell is in a(n) ______ solution

hypertonic

If a solution has a lower solute concentration than the interior of a cell, then the solution is ______ compared to the cell interior

hypotonic

If more water is entering a human red blood cell than exiting it, then the cell is surrounded by a(n) ______ solution

hypotonic

Most of the ATP molecules in eukaryotic cells are made in organelles called ______ during cellular respiration

mitochondria

Like the subunits of DNA and RNA, ATP is a type of

nucleotide

Select all of the following that describe exergonic reactions

release energy reactions that break large molecules into smaller components

Select all of the following that are true about the sodium-potassium pump

requires ATP moves potassium into the cell up its concentration gradient moves sodium out of the cell up its concentration gradient

Changes in which of the following can affect activity of enzymes

salt concentration pH temperature

The ______ states that all energy transformations lose heat to the environment

second law of thermodynamics

Membranes of organelles and cells only allow specific ions, atoms, and molecules to pass because membranes are

selectively permeable

The movement of substances from an area of high concentration to an area of low concentration without the assistance of proteins is a membrane transport process called

simple diffusion

What describes osmosis

simple diffusion of water

Match the methods of membrane transport with the correct descriptions

simple diffusion- movement of solutes from high to low concentration without a transport protein facilitated diffusion- movement of solutes from high to low concentration with a transport protein osmosis- movement of water from areas of high water concentration (low solute concentration) to areas of low water concentration (high solute concentration) active transport- movement of solutes from low to high concentration with a transport protein

What type of molecule is likely to be able to cross a membrane by simple diffusion

small and nonpolar

Select all the substances that can pass freely through the membrane by simple diffusion

small nonpolar molecules carbon dioxide oxygen lipids

Only specific ______ can bind to an enzyme's active site, and each particular enzyme can only catalyze specific chemical reactions

substrates

Select all of the cellular processes that require ATP

synthesizing large molecules active transport of substances across the membrane moving chromosomes in cell division

What is an example of a phosphorylation reaction

transfer of a phosphate group to glucose

True or false: Living organisms would not be able to survive without enzymes because reactions would proceed too slowly.

true

True or false: The more disordered a system is, the higher its entropy

true

True or false: The solute molecules in the picture series from left to right are moving down their concentration gradient as they disperse throughout the cup.

true

True or false: The total amount of energy in the universe is constant

true

_____ pressure is the force of water against a plant cell wall and helps maintain the shape of plant cells

turgor

Plant cells are hypertonic compared to the surrounding soil. This helps to promote water movement into the cell, which generates

turgor pressure

What describes simple diffusion

A substance moves down its concentration gradient

Adenosine diphosphate is also known as

ADP

In cells that consume a great deal of energy, such as brain cells and muscle cells, mitochondria are plentiful because they are organelles that produce

ATP

The energy molecule __________ is not stored in large quantities in cells because its high-energy phosphate bonds are too unstable

ATP

What molecule is composed of three phosphate groups and the base adenine bound to the five-carbon sugar ribose

ATP

What molecule temporarily stores energy in cells

ATP

What type of reaction is shown in the image

ATP hydrolysis

The region where a substrate (reactant) binds to an enzyme is called the ______ site.

Active

Select all of the reasons why organisms can maintain a high degree of organization even though all energy transformations release heat (disordered energy)

Energy is continually supplied to ecosystems. The complexity of something else in the universe is simultaneously decreasing.

True or false: A phosphate group can be removed from ATP but cannot be replaced

False

Knifefish have an electric organ, as described in this chapter's Investigating Life essay. What is the function of the knifefish electric organ

It generates an electric field that detects objects and organisms

Match the sentence fragments to create true statements about energy transfers

Kinetic energy in sunlight- is converted to potential energy in glucose during photosynthesis. is converted to potential energy in glucose during photosynthesis. The energy present in chemical bonds- is liberated during cellular respiration and used to make ATP. is liberated during cellular respiration and used to make ATP. Heat energy- is lost during every energy transformation. is lost during every energy transformation

Phosphorylation may energize a target molecule to bond with other molecules or change the ______ of a target molecule

Shape

When the gradient of a particular solute across a membrane has dissipated due to diffusion, what can be said about the solutions on either side of the membrane

The concentrations of the solutions are in equilibrium

If a solute is more concentrated in one location than another, it forms

a concentration gradient

What is entropy?

a measure of disorder in a system

ATP powers reactions and processes in

all types of cells

A person with phenylketonuria (PKU) lacks

an enzyme that breaks down an amino acid

Select all of the following that are enzyme inhibitors

aspirin antibiotics glyphosate in Roundup

Select all of the examples of energy-requiring work that organisms perform

assemble molecules rearrange atoms move ions

Select all of the examples of potential energy

ball at the top of a hill chemical energy stored in bonds unburned gasoline

In ATP hydrolysis, the ______ between the phosphate groups in ATP are broken with the addition of water

covalent bonds

Where is the most energy stored in an ATP molecule

covalent bonds between phosphates

The spontaneous movement of a substance from a region where it is more concentrated to a region where it is less concentrated is called

diffusion

If an ion moves from an area where it is more concentrated to an area where it is less concentrated, the ion is moving

down its concentration gradient

A(n) _______ transport chain is a group of proteins aligned in a membrane that releases energy at each step in the chain and that plays a role in both photosynthesis and respiration

electron

What molecule in the picture of an electron transport chain will become reduced

electron acceptor molecule

In oxidation-reduction reactions, energized ______ are transferred from one molecule to another.

electrons

Molecules that are reduced gain electrons plus any energy the electrons contain, making reduction reactions ______ (requiring a net input of energy)

endergonic

Photosynthesis is an example of a(n) ________ reaction because its products contain more energy than its reactants; conversely, cellular respiration is a(n) _______ reaction

endergonic exergonic

Match the type of chemical reaction with its correct description

endergonic reaction- Atoms or small molecules are often combined into large molecules in this type of reaction. exergonic reaction- Large molecules are often broken into smaller molecules or atoms in this type of reaction.

In a process called ______, a cell engulfs material and brings it into the cell in a vesicle pinched off the cell membrane

endocytosis

Pinocytosis is a type of

endocytosis used by cells to engulf fluids and dissolved substances

A concentration gradient will dissipate unless ______ is expended to maintain a higher concentration in one area compared to the other

energy

ATP hydrolysis releases the endmost phosphate group from ATP, yielding ADP, a phosphate group, and a burst of ______ that the cell can use to do work

energy

Cellular work, such as rearranging atoms and molecules, and multicellular work, such as moving body parts or substances, both require

energy

In an electron transport chain, ______ is captured from electrons as they are passed between proteins called electron carriers

energy

In passive transport, no _______ is spent to move a substance across a membrane

energy

Photosynthesis is an endergonic reaction because the products contain more________ than the reactants

energy

Some ______ will be lost to the surroundings as heat in every chemical reaction

energy

The ability to do work is called

energy

Although both endergonic and exergonic reactions require an initial energy input to get them started, ______ reactions release more energy than the amount needed to get them started

exergonic

The figure shows a(n) ______ reaction, in which the products contain less energy than the reactants

exergonic

The input of energy required by endergonic reactions is often provided by the energy released during ______ reactions

exergonic

In a membrane transport process called ______, a cell transports large molecules to the cell membrane in vesicles and releases them to the outside of the cell

exocytosis

What process is occurring in the picture, proceeding from panel 1 at the top to panel 3 at the bottom

exocytosis

As described in this chapter's Investigating Life essay, a knifefish can change the intensity of its electric field. How does the knifefish increase the "volume" of the electric field by changing the number of ion channels in its cell membranes

exocytosis of vesicles containing ion channels

In an example of ______, hydrogen ions (H+) move down their concentration gradient through a protein channel in the cell membrane

facilitated diffusion

Membrane proteins assist ions and polar molecules across membranes down their concentration gradient in

facilitated diffusion

What type of membrane transport is shown in the picture and requires a carrier molecule, but not ATP

facilitated diffusion

What types of molecules do cells use for long-term energy storage? Select all that apply

fats glycogen starch

The ______ states that energy cannot be created or destroyed; it can only change forms

first law of thermodynamics

Select all of the components of an ATP molecule

five-carbon sugar ribose nitrogenous base adenine three phosphate groups

What reaction is an endergonic reaction

formation of ATP from ADP

When a phosphate group is added to a molecule, the energy of the molecule

increases

Endocytosis is the process of transporting substances

into the cell using vesicles

One food Calorie (with an uppercase "C") is actually one ______, which is equal to 1,000 calories (with a lowercase "c")

kilocalorie

The energy being used to do work is called ________ energy and is the energy of motion

kinetic

In the process of photosynthesis, ______ in sunlight is converted into ______ in the bonds of glucose molecules

kinetic energy; potential energy

What type of substance must enter and exit cells within vesicles

large particles or molecules

In cellular respiration, which is an exergonic reaction, the amount of energy in the products is ______ that in the reactants

less than

Select all of the following that are examples of kinetic energy

light a rolling cart the movement of molecules sound

How do enzymes speed up biochemical reactions

lower the activation energy

The concentrations of solutes between the interior and the exterior of a cell or organelle may be chemically different because the ______ is selectively permeable

membrane

The production of new molecules and the breakdown of old molecules in the cell is called

metabolism

________ is the term that describes all the chemical reactions that occur in a cell, including the building of molecules and breaking down of molecules.

metabolism

In ______ feedback of a metabolic pathway, the product of a reaction inhibits the enzyme that controls its formation

negative

What process does the picture illustrate?

negative feedback

______ inhibition occurs when a molecule attaches to the enzyme at a location other than the active site and changes the shape of the enzyme so that it cannot bind to the correct substrate

noncompetitive

What process is occurring in the diagrams

noncompetitive inhibition

Coenzymes are enzyme cofactors that are

organic molecules

The diffusion of water across a membrane down its own concentration gradient and toward the region with a higher solute concentration is called

osmosis

The image shows the diffusion of water across a membrane, which is called

osmosis

Exocytosis is the process of transporting substances

out of the cell using vesicles

A(n) ______ reaction is an exergonic reaction because energy is released from an atom or a molecule with loss of an electron

oxidation

The loss of an electron from an atom or a molecule is called

oxidation

Electron carriers are ______ when they donate electrons in the electron transport chains of cellular respiration and photosynthesis

oxidized

Redox reactions occur simultaneously: for every molecule that is reduced (gains electrons), another molecule is ______ (loses electrons).

oxidized

Electrons are transferred from one molecule to another in

redox reactions

When an atom or a molecule gains an electron, it has been

reduced.

In redox reactions, when one molecule is ______ and gains electrons, another molecule must be ______ and lose electrons

reduced; oxidized

What is the process whereby an ion, an atom, or a molecule crosses a membrane without using energy

passive transport

What process captures large particles and brings them into the cell without the use of receptors

phagocytosis

_______ is a type of endocytosis used by cells to engulf bulk matter, including debris and other cells

phagocytosis

An ATP molecule is unstable and primed to release energy because its ______ groups are negatively charged and repel each other

phosphate

When a phosphate group is transferred from one molecule to another, the process is called

phosphorylating

What process brings liquid matter into the cell through transport vesicles

pinocytosis

The active site of an enzyme is the

place on the enzyme where substrates bind

In _________ feedback, the product of a reaction activates the pathway that catalyzes its production

positive

In a series of three enzymes called X, Y, and Z, the product of enzyme Z activates enzyme X to catalyze a reaction. This is an example of

positive feedback

A concentration gradient is a form of ______ energy because energy that can be used to drive molecular motion is stored in the gradient

potential

Stored energy available to do work is called ______ energy

potential

The stored energy available to do work is called ______ energy.

potential

Stored energy that can be used to do work is called _______ energy, while energy of motion that is being used to do work is called _______ energy

potential kinetic

The energy contained in the covalent bonds of molecules is a form of ______, which can be converted to kinetic energy that the cell can use to do work

potential energy

Match the energy form to its correct examples

potential energy- a sandwich; a concentration gradient of a chemical that has not dissipated a sandwich; a concentration gradient of a chemical that has not dissipated kinetic energy- fish swimming; the sound of a horn fish swimming; the sound of a horn

Select two ways that cells maintain concentration gradients

producing more of the solutes that diffuse out consuming solutes that diffuse in

Select all of the following that describe endergonic reactions

products contain more energy than the reactants require an input of energy photosynthesis is an example

A more selective type of endocytosis called receptor-mediated endocytosis occurs when a substance to be taken into the cell must bind to a(n) ______ on the cell's surface

protein

Although a small number of enzymes are RNA, most enzymes are ______

proteins

What causes diffusion of a substance

random molecular motion

Select all of the following that are occurring in the image

random molecular motion diffusion

One way that enzymes speed up reactions is to bring the ______ of the reaction together

reactants

In ______-mediated endocytosis, the binding of a substance to a protein on the cell surface triggers endocytosis

receptor

In redox reactions, what molecule gains potential energy

the electron acceptor molecule

The study of energy transformations is called

thermodynamics

The sodium-potassium pump moves

three Na+ ions out of the cell for every two K+ ions it moves into the cell