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WorksheetsAP Bio ch. 6: An Introduction to Metabolism
Total questions: 92
Worksheet time: 5hrs 36mins
A specific molecule is altered in a series of defined steps that result in a product.
metabolic pathways
catabolic pathways
anabolic pathways
energy pathways
molecular pathways
Process that releases energy by breaking down complex molecules into simpler ones .
metabolic pathway
catabolic pathway
anabolic pathway
energy pathway
molecular pathway
Cellular respiration is an example of a(n)...
metabolic pathway
catabolic pathway
anabolic pathway
energy pathway
molecular pathway
Process in which energy is absorbed to build complex molecules from simpler ones.
metabolic pathways
catabolic pathways
anabolic pathways
energy pathways
molecular pathways
Bioenergetics is the...
study of how energy flows through living organisms.
study of how energy flows through an ecosystem.
study of harnessing biological energy for mechanical use.
The energy associated with the movement of objects.
Kinetic Energy
Thermal Energy
Heat
Potential energy
Chemical Energy
Energy associated with the random movement of atoms or molecules.
Kinetic Energy
Thermal Energy
Heat
Potential Energy
Chemical Energy
Thermal energy in transfer from one object to another.
Kinetic Energy
Heat
Potential Energy
Chemical Energy
Energy of non-moving objects, energy due to location or structure.
Kinetic Energy
Thermal Energy
Heat
Potential Energy
Chemical Energy
The energy available for release in a chemical reaction.
Kinetic Energy
Thermal Energy
Heat
Potential Energy
Chemical Energy
The study of energy transformations that occur in a collection of matter.
Bioenergetics
Thermodynamics
Thermoenergetics
Biodynamics
Energy can be neither created nor destroyed.
First law of Thermodynamics
Second law of Thermodynamics
First law of Bioenergetics
Second law of Bioenergetics
Every energy transfer of transformation increases the entropy of the universe.
First law of Thermodynamics
Second law of Thermodynamics
First law of Bioenergetics
Second law of Bioenergetics
True or False. Entropy is a measurement of disorder and randomness.
True
False
A process that can occur without input of energy.
Endergonic Reaction
Spontaneous Process
Intra-running Process
Metabolic Process
Exergonic Reaction
True or False. Entropy can decrease in a system.
True
False
The portion of a system's energy that is available to perform work.
Heat
Potential Energy
Free Energy
Thermal Energy
Kinetic Energy
If a process is spontaneous, it will have a....
negative /\G
positive /\G
A system that loses energy during the reaction and has stable products has...
negative /\G
positive /\G
Equilibrium occurs when...
the forward and reverse reactions occur at the same rate.
both the forward and reverse reactions stop.
G is at the lowest possible value.
there is no change in products or reactants.
Characteristics of an Exergonic Reactions
Absorbs free energy.
Net release of free energy.
They occur spontaneously.
Negative /\G
Positive /\G
Characteristics of an Endergonic Reaction.
Absorption of free energy from surroundings.
Net release of free energy.
Positive /\G
Negative /\G
Spontaenous
Free Energy can represent...
the amount of work capable of being performed in an exergonic reaction.
the amount of work capable of being performed in an endergonic reaction.
the amount of energy required to drive the reaction in an exergonic reaction.
the amount of energy required to drive the reaction in an endergonic reaction.
When metabolic reactions in organisms reach equilibrium...
the cell is dead.
no work can occur.
the cell is dormant.
the cell becomes mature.
the cell divides.
Cells do which of the following to stop their metabolism from reaching equilibrium?
Maintaining flow of materials in and out of the cell.
Using products as reactants in a different reaction.
Expelling waste products.
Using enzyme inhibitors.
Feedback inhibition.
The use of an exergonic reaction to drive an endergonic one.
Energy Coupling
Reaction Coupling
Negative Energy Loop
Positive Energy Loop
Which of the following amounts of free energy emitted from an exergonic reaction could do the most work?
5 kcal
8 kcal
-5 kcal
-8 kcal
ATP Hydrolysis is an example of an...
endergonic reaction.
exergonic reaction.
The Phosphorylated intermediate is the...
Middle phosphate group on an ATP.
Last phosphate group on an ATP.
The molecule that a phosphate group from an ATP covalently bonds to.
The molecule that loses a phosphate group to make ATP from ADP.
True or False. A phosphorylated intermediate is less reactive than the unphosphorylated molecule but is more stable.
True
False. It is more reactive and more stable.
False. It is less reactive and less stable.
False. It is more reactive and less stable.
ATP causes motor proteins to "walk" because...
it supplies enough free energy for them to move forward.
it changes the shape of the protein.
it changes the molecular structure of the protein.
Making ATP from ADP is...
an endergonic reaction.
an exergonic reaction.
a catabolic process.
an anabolic process.
Thing to Review: The ATP Cycle
A
B
The best definition of Activation Energy.
Energy required for a reaction to occur.
Energy required to contort the reactants of a molecule so that the bonds can break.
Energy that is used to activate an enzyme.
Enzymes _____ activation energy.
decrease
increase
do not change
The reactant of an enzyme.
Substrate
Cofactors
Coenzymes
Inhibitors
True or False. Enzymes operate with a variety of reactions.
True
False
True or False. An induced fit is when an enzyme adjusts to admit substrates that are not it's usual reactants.
True
False
True or False. An induced fit is when an enzyme adjusts to have a tighter hold on its substrates.
True
False
True or False. Enzymes can only operate in one direction.
True
False
True or False. Enzymes stretch molecules into their transition state to lower the activation energy.
True
False
True or False. Enzymes supply free energy to lower the activation energy of substrates.
True
False
True or False. Enzymes create their own microclimates.
True
False
A cell is saturated when...
all of the enzymes have engaged active sites.
half of the enzymes have engaged active sites.
none of the enzymes have engaged active sites due to inhibitors and there are substrates filling the cell.
there are more enzymes than substrates
When temperature increases...
bonds that stabilize protein structure can break and the enzymes denature.
substrates collide more with active sites due to increased movement.
substrates collide less with active sites due to less movement.
bonds that stabilize protein structure become tighter.
Enzymes typically work best in a pH of...
3-5
6-8
2-4
7-10
True or False. Stomach Digestive enzymes operate best in an alkaline pH.
True
False
Nonprotein adjuncts required by some enzymes to help catalytic activity.
Cofactors
Coenzymes
Noncompetitive Inhibitor
Feedback Inhibitor
A coenzyme is a(n)...
organic cofactor.
organic inhibitor.
collection of subunit enzymes in a ring.
collection of enzymes that operate in a chain.
Inhibitors that mimic the shape of a substrate and take its place in the enzyme.
Competitive Inhibitor
Noncompetitive Inhibitor
Feedback Inhibitor
Structural Inhibitor
Inhibitors that bind to another part of the enzyme and cause a shape change in the active site.
Competitive Inhibitors
Noncompetitive Inhibitors
Feedback Inhibitors
Structural Inhibitors
Any case in which a protein's function is affected by the binding of a regulatory protein.
Allosteric Regulation
Cooperativity
Feedback Inhibition
Structural Inhibition
True or False. Enzymes have an active and an inactive site.
True
False
True or False. For an activator or inhibitor to lock enzyme subunits into an active or inactive shape, they must bond to all enzymes in the unit.
True
False. They only need to bond to one.
A substrate bonds and triggers a shape change in other units of the enzyme ring that amplify the response.
Allosteric Regulation
Cooperativity
Feedback Inhibition
Structural Inhibition
A metabolic pathway that is switched off by the inhibitory binding of the end product to an enzyme earlier in the pathway.
Allosteric Regulation
Cooperativity
Feedback Inhibition
Structural Inhibition
If ATP production is low, ADP activates enzymes that make ATP. If ATP production is high, the ATP acts as an inhibitor and bonds to the enzymes to stop ATP synthesis. What is this?
Feedback Inhibition
Cooperativity
Allosteric Regulation
Energy Coupling
Which term most precisely describes the cellular process of breaking down large molcules into smaller ones?
Catalysis
Metabolism
Anabolism
Dehydration
Catabolism
Which of the following is true for anabolic pathways?
They do not depend on enzymes.
They are usually highly spontaneous chemical reactions.
They consume energy to build up polymers from monomers.
They release energy as they degrade polymers to monomers.
They consume energy to decrease the entropy of the organism and its environment.
For living organisms, which of the following is an important consequence of the first law of thermodynamics?
The energy content of an organism is constant.
The organisms ultimately must obtain all of the ncessary energy for life from its environment.
The entripy of an organism decreases with time as the organism grows in complexity.
Organisms grow by converting energy into organic matter.
Life does not obey the first law of thermodynamics.
Which of the following statements is representative of the second law of thermodynamics?
Conversion of free energy from one form to another is always accompanied by some gain of free energy.
Heat represents a form of energy that can be used by most organisms to do work.
Without an input of energy, organisms would tend toward decreasing entropy.
Cells require a constant input of energy to maintain their high level of organization.
Every energy transformation by a cell decreases the entropy of the universe.
Which of the following types of reactions would decrease the entropy within a cell?
Anabolic Reactions
Hydrolysis
Respiration
Digestion
Catabolic Reactions
Which of the following is true of metabolism in its entirety in all organisms?
Metabolism depends on a constant supply of energy from food.
Metabolism depends on an organism's adequate hydration.
Metabolism uses all of an organism's resources.
Metabolism consists of all the energy transformation reactions in an organism.
Metabolism manages the increase on entropy in an organism.
The mathematical expression for the change in free energy of a system is /\G=/\H-T/\S. Which of the following is correct? (and those are deltas)
/\S is the change in enthalpy, a measure of randomness.
/\H is the change in entropy, the energy available to do work.
/\G is the change in free energy.
T is the temperature in degrees Celsius.
Which of the following is true for all exergonic reactions?
The products have more total energy than the reactants.
The reaction proceeds with a net release of free energy.
The reaction goes only in a forward direction: all reactants will be converted to products, but no products will be converted to reactants.
A net input of energy from the surroundings is required for the reactions to proceed.
The reactions are rapid.
A chemical reaction that has a positive /\G is best described as...
endergonic.
entropic.
enthalpic.
spontaneous.
exergonic.
For the hydrolysis of ATP to ADP + P, the free energy change is -13 kcal/mol in a cellular environment. What can we conclude about the free-energy change for the formation of ATP from ADP and P under cellular conditions?
It is +7.3 kcal/mol.
It is less than +7.3 kcal/mol.
It is about +13 kcal/mol.
It is greater than +13 kcal/mol.
Why is ATP an important molecule in metabolism?
Its hydrolysis provides an input of free energy for exergonic reactions.
It provides energy coupling between exergonic and endergonic reactions.
Its terminal phosphate group contains a strong covalent bond that, when hydrolyzed, releases free energy.
Its terminal phosphate bond has higher energy than the other two.
It is one of four buildings blocks for DNA synthesis.
Which of the following is most similar in structure to ATP?
A pentose sugar
A DNA nucleotide
An RNA nucleotide
An amino acid with three phosphate groups attached
A phospholipid
Which of the following statements is true concerning catabolic pathways?
They combine molecules into more energy-rich molecules.
They supply energy, primarily in the form of ATP, for the cell's work.
They are endergonic.
They are spontaneous and do not need enzyme catalysis.
They build up complex molecules such as protein from simpler compounds.
Which of the following statements is true about enzyme-catalyzed reactions?
The reaction is faster tan the same reaction in the absence of the enzyme.
The free-energy change of the reaction is opposite from the reaction that occurs in the absence of the enzyme.
The reaction always goes in the direction toward chemical equilibrium.
Enzyme-catalyzed reactions require energy to activate the enzyme.
Enzyme-catalyzed reactions release more free energy than noncatalyzed reactions.
Reactants capable of interacting to form products in a chemical reaction must first overcome a thermodynamic barrier known as the reaction's...
entropy.
activation energy.
endothermic level.
equilibrium point.
free-energy content.
Which of the following statements regarding enzymes is true?
Enzymes increase the rate of a reaction by making the reaction more exergonic.
Enzymes increase the rate of a reaction by lowering the activation energy barrier.
Enzymes increase the rate of a reaction by reducing the rate of reverse reactions.
Enzymes change the equilibrium point of the reactions they catalyze.
Enzymes make the rate of a reaction independant of substrate concentrations.
During a laboratory experiment, you discover than an enzyme-catalyzed reaction has a /\G of -20 kcal/mol. If you double the amount of enzym in the reaction, what will be the /\G for the new reaction?
-40 kcal/mol
-20 kcal/mol
0 kcal/mol
+20 kcal/mol
+40 kcal/mol
The active site of an enzyme is the region that...
binds allosteric regulators of the enzyme.
is involved in the catalytic reaction of the enzyme.
binds noncompetitive inhibitors of the enzyme.
is inhibited by the presence of a coenzyme of a cofactor.
According to the induced fit hypothesis of enzyme catalysis, which of the following is correct?
The binding of the substrate depends on the shape of the active site.
Some enzymes change their structure when activators bind to the enzyme.
A competitive inhibitor can outcompete the substrate for the acive site.
The binding of the substrate changes the shape of the enzyme's active site.
The active site creates a microenvironment ideal for the reaction.
Increasing the substrate concentration in an enzymatic reaction could overcome which of the following?
Denaturation of the enzyme.
Allosteric inhibition.
Competitive inhibition.
Saturation of the enzyme activity.
Insufficient cofactors.
Which of the following is true of enzymes?
Nonprotein cofactors alter the substrate specificity of enzymes.
Enzyme function is increased if the 3-D structure or conformation of an enzyme is altered.
Enzyme function is independant of physical and chemical environmental factors such as pH and temperature.
Enzymes increase the rate of chemical reaction by lowering activation energy barriers.
Enzymes increase the rate of cehmcial reaction by providing activation energy to the substrate.
Zinc, an essential trace element for most organisms, is present in the active site of the enzyme carboxypeptidase. The zinc most likely functions as a(n)...
competitive inhibitor of the enzyme.
noncometitive inhibitor of the enzyme.
allosteric activator of the enzyme.
cofactor necessary for enzyme activity.
coenzyme derived from a vitamin.
To attach a particular amino acid to the tRNA molecule that will transport it, an enzyme, an aminoacyl-tRNA synthetase, is required, along with ATP. Initially, the enzyme has an active site for ATP and another for the amino acid, but it is not able to attach the tRNA. What must occur for the final attachment?
The ATP must first have to attach to the tRNA.
The binding of the first two molecules must cause a 3-D change that opens another active site on the enzyme.
The ATP must be hydrolyzed to allow the amino acid to bind to the synthetase.
The tRNA molecule must have to alter its shape to be able to fit into the active site with the other two molecules.
The 3' end of the tRNA must have to be cleaved before it can have an attached amino acid.
Protein kinases are enzymes that transfer the terminal phsophate from ATP to an amino acid residue on the target protein. Many are located on the plasma membrane as integral membrane proteins or peripheral membrane proteins. What purpose may be served by their plasma membrane localization?
ATP is more abundant near the plasma membrane.
They can more readily encounter and phosphorylate other membrane proteins.
Membrane localization lowers the activation energy of the phosphorylation reaction.
They flip back and forth across the membrane to access target proteins on either side.
They require phospholipids as a cofactor.
Whne you have a severe fever, what grave consequence may occur if the fever is not controlled?
Destruction of your enzymes' primary structure.
Removal of an amine groups from your proteins.
Change in the tertiary structure of your enzymes.
Removal of the amino acids in the active sites of your enzymes.
Binding of your enzymes to inappropriate substrates.
How does a noncompetitive inhibitor decrease the rate of an enzyme reaction?
By binding at the active site of the enzye.
By changing the shape of the enzyme's active site.
By changing the free-energy change of the reaction.
By acting as a coenzyme for the reaction.
By decreasing the activation energy of the reaction.
The mechanism in which the end product of a metabolic pathway inhibits an earlier step in the pathway in most precisely described as...
metabolic inhibition.
feedback inhibition.
allosteric inhibition.
noncooperative inhibition.
reversible inhibition.
Which of the following is an example of cooperativity?
The binding of an end product of a metabolic pathway to the first enzyme that acts in the pathway.
One enzyme in a metabolic pathway passing its product to act as a substrate for the next enzyme in the pathway.
A molecule binding at one unit of a tetrameter, allowing faster binding at each of the other three.
The effect of increasing temperature on the rate of an enzymatic reaction.
Binding of an ATP molecule along with one of the substrate molecules in an active site.
Important Note: Questions from the test that were acommpanied by graphs are not included. Review those.
Okay.
Also Okay.
Succinate dehydrogenase catalyzed the conversion of succinate to fumarate. The reaction is inhibited by malonic acid, which resembles succinate but cannot be acted upon by succinate dehydrogenase. Increasing the ratio of succinate to malonic acid reduces the inhibitory effect of maolonic acid. Which of the following is correct.
Succinate dehydrogenase is the enzyme and fumarate is the substrate.
Succinate dehydrogenase is the enzyme, and malonic acid is the substrate.
Succinate is the substrate, and fumarate is the product.
Fumarate is the product, and malonic acid is a noncompetitive inhibitor.
Malonic acid is the product, and fumarate is a competitive inhibitor.
A series of enzymes catalyze the reaction X > Y > Z > A. Product A binds to the enzyme that converts X to Y at a position remote from its active site. This binding decreases the activity of the enzyme. What is substance X?
A Coenzyme
An allosteric inhibitor
A substrate
An intermediate
The product
Catabolism is to anabolism as ________ is to _________.
exergonic and spontaneous
exergonic and endergonic
free energy and entropy
work and energy
entropy and heat
If an enzyme in solution is saturated with substrate, the most effective way to obtain a faster yield of products is to...
add more of the enzyme.
heat the solution to 90 C.
add more substrate.
add an allosteric inhibitor.
add a noncompetitive inhibitor.
Some bacteria are metabolically active in hot springs because...
they are able to maintain a lower internal temperature.
high temperatures make catalysis unnecessary.
their enzymes have high optimal temperatures.
their enzymes are completely insensitive to temperature.
they use molecules other than proteins or RNAs as their main catalysts.
If an enzyme is added to a solution where its substrate and product are in equilibrium, what will occur?
Additional product will be formed.
Additional substrate will be formed.
The reaction will change from endergonic to exergonic.
The free energy of the system will change.
Nothing; the reaction will stay at equilibrium.
