Deck 3: Energy,Chemical Reactions,and Cellular Respiration

Question 1

__________ is a monomer that is stored as the polymer glycogen within the liver and muscle.

Answer 1

Glucose

Question 2

The first law of thermodynamics states that once energy is consumed,it can no longer be converted to any other form of energy.

Answer 2

False

Question 3

The form of kinetic energy that refers to the movement of electromagnetic waves is _________ energy.

Answer 3

radiant

Question 4

Chemical reactions that release energy are called __________ reactions.

Question 5

The energy of motion is known as _________ energy.

Question 6

Which is a form of energy that is generally unavailable to do any work

A)Heat
B)Kinetic energy
C)Radiant energy
D)Sound energy
E)Mechanical energy

Question 7

Three molecules that are important energy storage locations in the body are

A)DNA,tRNA,and rRNA.
B)glucose,glucagon,and glycogen.
C)ATP,glycogen,and triglyceride.
D)ADP,DNA,and mRNA.
E)glucagon,insulin,and protein.

Question 8

The energy stored in a molecule's chemical bonds is a form of kinetic energy.

Question 9

The propagation of an impulse along the axon of a neuron is considered electrical energy,a form of kinetic energy.

Question 10

According to the second law of thermodynamics,when energy is transformed from one kind to another

A)some of it is converted to heat.
B)some energy is destroyed.
C)new energy is created.
D)homeostasis is maintained.
E)chemical bonds must be broken.

Question 11

The reaction in which water and carbon dioxide combine to form carbonic acid is

A)irreversible,as carbonic acid rapidly causes a drop in pH.
B)reversible,and can proceed in either direction depending on the concentrations of the molecules.
C)exergonic,and is an important energy source within the body.
D)an exchange reaction in which protons are transferred between atoms.
E)a catabolic reaction in which the formation of a larger molecule can lead to an increase in cell size.

Question 12

The building of complex molecules from simpler ones is described as

A)anabolism.
B)catabolism.
C)exergonic.
D)irreversible.
E)reversible.

Question 13

Typically,synthesis reactions are endergonic.

Question 14

As a runner sprints down a track,her movement is an example of

A)potential energy.
B)mechanical energy.
C)heat.
D)radiant energy.
E)chemical energy.

Question 15

Stored energy is described as potential energy.

Question 16

When we shiver on a cold day,the heat produced by muscle tissue is a demonstration of

A)radiant potential energy.
B)the first law of thermodynamics.
C)the second law of thermodynamics.
D)the creation of energy.

Question 17

The sodium level inside and outside of a resting cell is an example of the

A)kinetic energy of sodium rushing out of a cell down its concentration gradient.
B)kinetic energy of the large difference in sodium concentration on the inside versus the outside of the cell.
C)potential energy of a concentration gradient,because sodium is more abundant outside the cell.
D)potential energy of an electron transport chain,because sodium has an extra electron to donate.
E)conversion of potential energy to kinetic energy,because sodium can never move across the cell membrane and must move across its surface.

Question 18

When a car burns gasoline,the majority of the gasoline's chemical energy is transformed to sound and heat.

Question 19

Compare and contrast chemical energy and radiant energy.Into which broad category of energy (kinetic or potential)does each fit
What are two examples of each type of energy that relate to human physiology

Question 20

When our inner ears convert sound energy into neural impulses or our retinas convert light into neural impulses,

A)no heat is generated,and so it is an exception to the first law of thermodynamics.
B)it is an exception to both laws of thermodynamics,because no usable energy is lost.
C)it is consistent with the second law of thermodynamics,but an exception to the first.
D)the conversion is consistent with both laws of thermodynamics.

Question 21

Which one of the following choices includes three descriptions that are consistent with each other (that is,that describe the same type of chemical reaction)

A)Anabolic,dehydration,endergonic
B)Exchange,hydrolysis,endergonic
C)Catabolic,dehydration,irreversible
D)Metabolic,synthesis,exergonic
E)Anabolic,catabolic,dehydration

Question 22

Generally,a cell stores enough ATP to meet the energy requirements of a few

A)seconds.
B)minutes.
C)hours.
D)days.

Question 23

The region of an enzyme into which the substrate fits is a

A)one-size-fits-all active site.
B)highly specific active site.
C)highly specific antibody.
D)one-size-fits-all antibody.

Question 24

When the body's digestive system breaks down starch,a complex carbohydrate,into simpler carbohydrates,the reaction is

A)anabolic and endergonic.
B)anabolic and exergonic.
C)catabolic and exergonic.
D)catabolic and endergonic.

Question 25

Enzymes are biological catalysts that are crucial for normal human metabolism.

Question 26

Explain the relationship between activation energy and reaction rate.For example,how would an increase in activation energy affect reaction rate
How do biological systems differ from lab settings when considering these chemical variables

Question 27

In order for a reaction to occur,energy is needed to break the bonds that already exist in the reactant molecules;that energy is called the _________ energy.

Question 28

The term "activation energy" refers to the amount of energy

A)released by an exergonic reaction.
B)released by an endergonic reaction.
C)released by a catabolic reaction.
D)required to initiate any chemical reaction.
E)required to initiate only catabolic reactions.

Question 29

The exchange of a phosphate group between creatine phosphate and adenosine diphosphate is categorized as a catabolic (rather than anabolic)reaction.

Question 30

When NAD⁺becomes NADH,it is being

A)reduced and gaining chemical energy.
B)reduced and releasing chemical energy.
C)oxidized and gaining chemical energy.
D)oxidized and releasing chemical energy.

Question 31

Structurally,enzymes are generally

A)globular proteins.
B)fibrous proteins.
C)spherical carbohydrates.
D)elongated carbohydrates.
E)four-ring steroids.

Question 32

In the absence of the enzyme carbonic anhydrase,the combination of water and carbon dioxide to form carbonic acid does not occur.

Question 33

Exergonic reactions do not require activation energy.

Question 34

In a chemical reaction where an electron is exchanged from one reactant to another,the structure that loses an electron is

A)analyzed.
B)catalyzed.
C)oxidized.
D)reduced.

Question 35

In a redox reaction,when one reactant is oxidized,the other

A)is reduced.
B)is also oxidized.
C)is hydrolyzed into a smaller molecule.
D)releases chemical energy in the form of ATP.
E)becomes a larger,more complex molecule.

Question 36

A reaction with a very high activation energy should have a very high reaction rate.

Question 37

The term "metabolism" refers to

A)reactions involving the breakdown of complex molecules into simpler ones.
B)reactions involving the breakdown of complex molecules or the exchange of atoms between similarly sized reactants.
C)all the chemical reactions in the body.
D)reactions involving the synthesis of complex molecules from simpler ones.
E)digestive system reactions that are either catabolic or exchange reactions.

Question 38

ATP formation

A)is endergonic and liberates energy for cellular processes that require energy.
B)is endergonic and requires the presence of fuel molecules such as glucose.
C)is exergonic and liberates energy for cellular processes that require energy.
D)is exergonic and requires the presence of fuel molecules such as glucose.

Question 39

The presence of an enzyme within a chemical system

A)increases activation energy.
B)decreases activation energy.
C)increases potential energy.
D)does not affect either activation energy or potential energy.

Question 40

In a lab setting,heating a vessel full of reactants will generally

A)increase the kinetic energy of the molecules and increase the reaction rate.
B)raise the activation energy and catalyze the reaction.
C)lower the activation energy and the kinetic energy of the reactants.
D)convert products to reactants by increasing the energy requirements.
E)lower the reaction rate due to the change in structure of the reactants.

Question 41

The enzyme-substrate complex is

A)another name for the active site.
B)the reactants whose chemical reaction the enzyme catalyzes.
C)the chemical structure formed when the substrate binds to the active site.
D)a pocket on the substrate that the enzyme recognizes.

Question 42

Which answer lists the steps of enzyme action in correct order

A)Formation of enzyme-substrate complex,induced fit,formation or breakage of chemical bonds,release of product
B)Induced fit,formation of enzyme-substrate complex,formation or breakage of chemical bonds,release of product
C)Formation or breakage of chemical bonds,induced fit,formation of enzyme-substrate complex,release of substrate
D)Induced fit,formation or breakage of chemical bonds,formation of enzyme-substrate complex,release of product

Question 43

Organic cofactors are referred to as _________.

Question 44

When an enzyme's conformational change results in the enzyme hugging the substrate in its active site,the action is referred to as the __________ model of enzyme function.or

Question 45

Which enzyme class splits a chemical bond in the absence of water

A)Ligase
B)Oxidoreductase
C)Lyase
D)Hydrolase
E)Dehydrogenase

Question 46

When an enzyme catalyzing a catabolic reaction changes conformation to an induced fit with the substrate,

A)it strengthens the chemical bonds in the enzyme so that it remains perpetually active.
B)it stresses chemical bonds in the substrate,making it easier to break them.
C)it strengthens chemical bonds in the substrate so that cofactors can act on it.
D)it stresses chemical bonds in the enzyme so that the enzyme breaks into two catalytic subunits.

Question 47

An isomerase bonds two similar molecules together to form a larger one.

Question 48

Cofactors are generally proteins.

Question 49

Which enzyme class transfers electrons from one substance to another

A)Oxidoreductase
B)Transferase
C)Isomerase
D)Ligase
E)Electin

Question 50

The enzyme DNA polymerase is synthesized

A)at a ribosome,and it remains within the cell.
B)at the rough endoplasmic reticulum,and it is secreted from the cell.
C)at the Golgi apparatus,and it is embedded in the cell membrane.
D)in the nucleus,and it is converted to RNA for export outside the cell.

Question 51

An enzyme that is described as a protein kinase is a

A)hydrolase that removes an amino acid from a protein.
B)transferase that transfers a phosphate group to a protein substrate.
C)ligase that adds an amino acid to a protein.
D)isomerase that changes one protein into another.
E)protease that transfers electrons from one protein to another.

Question 52

Both pepsin and trypsin are proteins that digest proteins.

Question 53

Briefly describe how enzymes are named.What is generally used for the root of the name,and what is generally used as the suffix
Provide one example.

Question 54

In performing its enzymatic function,carbonic anhydrase

A)requires the inorganic coenzyme zinc.
B)requires the organic coenzyme carbon dioxide.
C)is facilitated by the inorganic coenzyme NAD⁺.
D)is facilitated by the organic coenzyme zinc.
E)requires the inorganic coenzyme NADPH.

Question 55

Saturation occurs when

A)there is so much enzyme present that the reaction rate decreases if more is added.
B)all enzymes are busy and further increases in substrate concentration will not increase reaction rate.
C)enzymes become fatigued and can no longer catalyze changes in the substrate.
D)intramolecular interactions are disrupted in the enzyme,decreasing its efficiency and decreasing reaction rate.
E)the substrate is denatured and the enzyme cannot catalyze any changes in its structure.

Question 56

In the final step of enzymatic catalysis,

A)the substrate is released and the enzyme is inactivated.
B)the product is completed and the enzyme is inactivated.
C)the products are released and the enzyme is free to bind other substrates.
D)the enzyme and substrate form chemical bonds with each other resulting in a new product.
E)equilibrium is obtained so that the enzyme does not catalyze further reactions.

Question 57

Pancreatic amylase serves its function when it is located in the

A)mouth.
B)blood.
C)liver.
D)stomach.
E)small intestine.

Question 58

Lactose intolerance is caused by the lack of the enzyme lactase,which is normally found in the

A)lumen of the stomach.
B)inside of cells of the liver and gall bladder.
C)membranes of cells in the small intestine.
D)inside of cells in the large intestine.
E)endothelium of capillaries in the large intestine.

Question 59

Which statement accurately describes the effects of substrate and enzyme concentrations on reaction rate

A)An increase in either substrate or enzyme concentration will increase the reaction rate.
B)An increase in either substrate or enzyme concentration will decrease the reaction rate.
C)An increase in substrate concentration increases the reaction rate,but enzyme concentration has no effect.
D)A decrease in substrate concentration or an increase in enzyme concentration increases the reaction rate.
E)An increase in substrate concentration or a decrease in enzyme concentration will increase the reaction rate.

Question 60

Lactase is an enzyme that digests lactose.

Question 61

Extremely high temperatures break intramolecular interactions and _________ an enzyme,resulting in a loss of its function.or

Question 62

At temperatures above 40 ^$\circ$ C (104 ^$\circ$ CF)in the human body,

A)enzymatic reactions with substrates are more quickly catalyzed.
B)enzymes denature and reaction rates decrease.
C)protein flexibility is optimum and reaction rates increase.
D)protein shape is rigid and reaction rates are constant.

Question 63

A substance that binds to the active site of an enzyme and turns it off is called a _________ inhibitor.

Question 64

The less acidic (more basic)the environment is,the more efficient an enzyme will be.

Question 65

Which enzyme system allows for regulation at a single site and also diminishes the chance that a needed substrate will diffuse away from a catalyst

A)Metabolic pathway
B)Multienzyme complex

Question 66

Noncompetitive inhibition of an enzyme occurs when the inhibitor binds to the

A)allosteric site,and its effectiveness is not influenced by substrate concentration.
B)allosteric site,and its effectiveness depends on substrate concentration.
C)active site,and its effectiveness is not influenced by substrate concentration.
D)active site,and its effectiveness depends on substrate concentration.
E)substrate,and its effectiveness depends on product concentration.

Question 67

The optimal pH range for the stomach enzyme pepsin is

A)2-4.
B)6-8.
C)7.3-7.4.
D)10-12.
E)12.0-13.5.

Question 68

A fever of 101 ^$\circ$ F causes most enzymes in the human body

A)to denature.
B)to become more rigid.
C)to be more flexible and efficient.
D)to saturate.

Question 69

The optimal pH range for most human enzymes is

A)1-2.
B)4-6.
C)6-8.
D)8-10.
E)13-14.

Question 70

A group of enzymes that are physically attached to one another is referred to as a(n)

A)allosteric pathway.
B)metabolic pathway.
C)multienzyme complex.
D)phosphate complex.

Question 71

Allosteric inhibitors are also called noncompetitive inhibitors.

Question 72

In the regulation of enzymes,negative feedback ensures that a lot of product can be made from only a little bit of substrate.

Question 73

Enzymes that remove phosphate groups from their substrates are called __________.or

Question 74

Enzyme saturation occurs when substrate levels are so high that all enzyme molecules are actively engaged in the chemical reaction,and so further increases in substrate concentration do not increase reaction rate.

Question 75

Enzyme regulation by negative feedback involves

A)allosteric inhibition of an enzyme by a product of its metabolic pathway.
B)allosteric facilitation of an enzyme by a substrate of its metabolic pathway.
C)allosteric modification of a substrate by an enzyme of an alternate metabolic pathway.
D)occupation of the active site of an enzyme so that it catalyzes less efficiently.
E)enhancement of the active site by a negatively charged substrate.

Question 76

A large decrease in pH results in increased H⁺binding to an enzyme,which can disrupt electrostatic interactions within the molecule.

Question 77

To prevent depletion of a substrate,the product of a metabolic pathway will

A)turn off an enzyme early in the pathway.
B)catalyze its own production.
C)increase enzyme activity through positive feedback.
D)occupy the active site of an enzyme early in the pathway.

Question 78

Generally,a decrease in substrate concentration leads to an increase in reaction rate.

Question 79

Cold temperatures (below 36 ^$\circ$ C)denature proteins,which is why biochemistry labs never freeze enzymes.

Question 80

When multiple enzymes are organized in a metabolic pathway,each enzyme catalyzes one reaction and then releases the product.