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