Deck 5: Bioenergetics: the Flow of Energy in the Cell

Question 1

In a chemical reaction,the standard free energy change (ΔG°')is calculated to be -3.67 cal/mol.What can be said of the chemical reaction?

A)The reaction is at equilibrium under standard conditions.
B)The reaction is spontaneous under standard conditions.
C)The reaction is not spontaneous under standard conditions.
D)Reactants predominate over products at equilibrium under standard conditions.
E)There can be no reaction.

Answer 1

B

Question 2

A negative free energy change indicates that

A)the reaction is not possible.
B)energy must be added to the reaction before it can proceed.
C)the reactant is predominant at equilibrium.
D)the reaction is exothermic.
E)the reaction is at equilibrium.

Answer 2

D

Question 3

Which of the following is an endothermic process?

A)combustion reactions
B)adding a strong acid directly to water
C)oxidation of metals
D)ice melting
E)neutralization reactions of the addition of strong acid directly to a strong base

Answer 3

C

Question 4

A spontaneous reaction

A)has to occur immediately.
B)will never occur.
C)has an overall positive free energy change.
D)could occur but might take a very long time.
E)is associated exclusively with homeothermic organisms.

Question 5

The statement,"The total amount of energy in the universe is constant," is a tenet of

A)the first law of thermodynamics.
B)the second law of thermodynamics.
C)thermodynamic spontaneity.
D)entropy.
E)enthalpy.

Question 6

Nerve impulses travel along the neurons by the opening of channels that allow sodium ions to flow inward,followed by an outward flow of potassium ions.In order to ensure that the impulse may be produced at any time,sodium is actively transported out of the cell,and potassium is transported into the cell by the sodium/potassium pump.Which of the following types of work is performed by the sodium/potassium pump?

A)mechanical
B)electrical
C)concentration
D)synthetic
E)bioluminescent

Question 7

In a reversible chemical reaction at equilibrium,the concentration of X (the reactant)is 0.75 mol/L,and the concentration of Y (the product)is 2.25 mol/L.At 25°C,what would be the Keq?

A)0.33
B)3.0
C)1.69
D)1.50
E)37.5

Question 8

Fireflies have the ability to convert the energy in ATP to light.Which of the following types of work is performed by the firefly?

A)bioluminescent
B)heat
C)concentration
D)electrical
E)mechanical

Question 9

Which of the following is defined as "heat content"?

A)energy output
B)heat loss
C)entropy
D)solar radiation
E)enthalpy

Question 10

Which of the following types of work involves a change in position of the cell or a cell structure?

A)bioluminescent
B)electrical
C)mechanical
D)synthetic
E)concentration

Question 11

Which of the following is not a basic need of the cell?

A)molecular building blocks
B)100% efficiency
C)energy
D)information
E)chemical catalysts

Question 12

All of the following are used as bioluminescent tools for cell biologists except

A)luciferase.
B)rhodopsin.
C)GFP.
D)YFP.
E)none of the above

Question 13

Which of the following is a heterotroph?

A)grass
B)a tree
C)a mushroom
D)a geranium
E)a cyanobacterium

Question 14

Which of the following is a phototroph?

A)a tree
B)a mushroom
C)bacteria growing on decomposing matter
D)an earthworm
E)a person

Question 15

Bioenergetics can be simply defined as

A)a subdivision of biology.
B)applied thermodynamics.
C)the units in which energy is expressed.
D)the application of biological principles to physics.
E)holding constant the variables in the universe.

Question 16

Animals that regulate their body temperature independently of the environment are called

A)heterotherms.
B)homeotherms.
C)poikilotherms.
D)biotherms.
E)abiotherms.

Question 17

In a chemical reaction,the standard free energy change (ΔG°')is calculated to be 3.67 cal/mol.What can be said of the chemical reaction?

A)The reaction is at equilibrium under standard conditions.
B)The reaction goes spontaneously to the right under standard conditions.
C)The reaction is not spontaneous under standard conditions.
D)Products predominate over reactants at equilibrium under standard conditions.
E)There can be no reaction.

Question 18

Muscle contraction is an example of which of the following types of work?

A)heat
B)mechanical
C)bioluminescent
D)electrical
E)concentration

Question 19

When the ΔG°' of a chemical reaction is positive (K'eq < 1.0)under standard conditions,

A)reactants and products are at equilibrium.
B)work can be done under these conditions.
C)reactants predominate over products.
D)the reaction is spontaneous to the right.
E)the reaction is exothermic.

Question 20

In a reversible reaction at equilibrium,the concentration of R (the reactant)is 3.0 mol/L and the concentration of P (the product)is 0.9 mol/L.At 25°C,what would be the Keq?

A)1.5
B)0.3
C)1.0
D)3.0
E)37.5

Question 21

Matter and energy flow through the biosphere.The flow of matter,however,differs from the flow of energy.Which of the following statements accurately describes these differences?

A)Matter flows in cycles, whereas energy flows in one direction.
B)Matter does not accompany energy as it enters the biosphere, but it does flow with energy from the biosphere.
C)Energy flows from chemotrophs to phototrophs, whereas matter flows from phototrophs to chemotrophs.
D)Energy flows as organic molecules are reduced to inorganic molecules, but matter does not.
E)Matter and energy flow sometimes in cycles and sometimes unidirectionally.

Question 22

Under the conditions of a given reaction,a positive ΔG' means

A)the reaction is spontaneous.
B)no energy needs to be added.
C)the reaction is at equilibrium.
D)work can be done.
E)the reaction will not occur.

Question 23

In a biochemical reaction,reactants may be converted into products.The extent to which this occurs spontaneously is expressed as which of the following?

A)ΔG
B)Keq
C)ΔS
D)temperature
E)TΔS

Question 24

The voodoo lily (Sauromatum guttatum)is able to

A)utilize metabolic heat.
B)be pollinated by flies.
C)emit a foul odor to attract pollinators.
D)trick the pollinators into thinking it is rotting meat.
E)all of the above

Question 25

Which is true of heterotrophs?

A)They capture light energy.
B)They cannot be unicellular.
C)They store energy in the form of heat.
D)They can function as autotrophs in an emergency.
E)They can obtain energy from consuming phototrophs.

Question 26

Energy is important to life forms because

A)all life forms require a continuous supply of it.
B)it is required to do work.
C)it is required to make specific alterations in the cell.
D)both choices A and B
E)choices A, B, and C

Question 27

Photosynthesis is an important process that

A)is performed by heterotrophs.
B)produces oxidized products.
C)uses water and carbon dioxide as reactants.
D)is performed by organisms living near deep-ocean thermal vents.
E)only plants can perform.

Question 28

The form of energy that is available to living organisms is in the form of

A)sunlight.
B)radiation.
C)chemical bonds.
D)nuclear energy.
E)heat.

Question 29

The steady state so vital to life is possible because

A)the cell cannot convert energy from one form to another.
B)all cells are autotrophic.
C)the cell continually takes up energy from the environment.
D)all reactions are at equilibrium.
E)all reactions are exothermic.

Question 30

Which is not true of phototrophs?

A)They capture light energy.
B)They can be bacteria.
C)They store energy as glucose.
D)They never function as autotrophs.
E)They provide energy for chemotrophs.

Question 31

When ΔG' = 0 in a chemical reaction,under standard conditions,

A)reactants and products are at equilibrium.
B)work can be done; energy is required.
C)the reaction is spontaneous to the left.
D)no work can be done; no energy is required.
E)both choices A and D

Question 32

Another name for an oxidizing agent is a(n)

A)electron acceptor.
B)electron donor.
C)reductant.
D)electropositive metal.
E)hydride transfer reagent.

Question 33

The statement,"Energy is neither created nor destroyed," describes

A)the first law of thermodynamics.
B)the second law of thermodynamics.
C)the law of conservation of energy.
D)enthalpy.
E)both choices A and C

Question 34

Aerobic refers to what property of chemotrophs?

A)Chemotrophs remove carbon dioxide from the air.
B)Chemotrophs require oxygen to produce energy.
C)Chemotrophs use, but do not require oxygen.
D)Fermentation releases great amounts of gas but only in chemotrophs.
E)Heat losses occur in the presence of oxygen.

Question 35

Oxidation

A)involves the removal of oxygen atoms.
B)is endothermic.
C)occurs when an atom accepts electrons.
D)occurs when oxygen is added and energy released.
E)both choices B and C

Question 36

Which of the following statements is not true of the value ΔH?

A)ΔH is the change in heat content.
B)ΔH is the change in enthalpy.
C)In biology, ΔH is basically the same as ΔE.
D)A reaction with a positive ΔH value is exothermic.
E)ΔH = ΔE + Δ(PV)

Question 37

A student drops his notes,and his papers scatter.The fact that the papers scatter and do not remain neatly stacked is an illustration of

A)the first law of thermodynamics.
B)the second law of thermodynamics.
C)an increase in entropy.
D)both choices A and B
E)both choices B and C

Question 38

In a cell,the concentration of glucose-6-phosphate is 83 μM and of fructose-6-phosphate is 14 μM.The ΔG°' = 410 cal/mol for the conversion of glucose-6-phosphate to fructose-6-phosphate.Based upon this information,the ΔG' for this reaction (in cal/mol)is

A)-644.
B)-63.7.
C)0.
D)27.
E)644.

Question 39

Which process involves an increase in entropy of the system?

A)freezing of ice
B)any spontaneous process
C)combustion of paper
D)formation of raindrops
E)synthesis of cellulose

Question 40

Reduction involves the

A)loss of neutrons.
B)gain of electrons.
C)increase in oxidation state.
D)both choices B and C
E)all of the above

Question 41

Identify each of the following examples as phototrophs or chemotrophs.If the example is a chemotroph,indicate whether the needs of the chemotroph are met with or without oxygen (aerobic and anaerobic).
a.A pine tree grows in a forest.
b.A wolf eats the remains of a deer.
c.Bacteria consume a rotting tree.
d.Bacteria grow in an unopened can of green beans.
e.A mushroom grows among pine needles.
f.Cyanobacteria are growing in a lake.
g.A woman goes jogging for one hour.
h.Microorganisms grow near a deep-ocean thermal vent.

Question 42

The standard state of dilute aqueous solutions is at a temperature of ________°C (298 K),________ atmosphere(s)of pressure,and with products and reactants present in concentration of ________ mol/L.

Question 43

A ________ is an organism that requires the intake of chemical compounds such as carbohydrates,fats,and proteins.

Question 44

Any process that results in an increase in the free energy of the system is called ________.

Question 45

________ reactions require an input of energy when electrons are gained,such as in the conversion CO₂ → CH₄.

Question 46

A ________ is the amount of energy required to warm 1 gram of water 1 degree Celsius.

Question 47

Any process that results in a decrease in the free energy of the system is called ________.

Question 48

________ is the partial measure of the internal energy of a system,also known as the heat content.

Question 49

In every physical or chemical change,energy cannot be created nor destroyed.This is the ________ law of thermodynamics.

Question 50

There are different types of biological work.Can you identify the type of work illustrated by the examples below?
a.A man lifts a barbell.
b.A sea creature glows in the dark.
c.Green plants perform carbon fixation.
d.During respiration,protons are transported across the membrane of the mitochondrion.
e.Humans maintain a constant body temperature.
f.Sodium is accumulated inside a cell.
g.A neuron transmits an impulse to a muscle cell.
h.Chromosomes are moved along the spindle fibers during mitosis.

Question 51

________ is the transfer of energy from one place or form to another place or form.

Question 52

In your own words,describe how energy flows through an ecosystem and how this contributes to a continuous increase in enthalpy.

Question 53

The total energy stored within a system is called the ________.

Question 54

The melting of ice is an example of a(n)___________ process.

Question 55

Fermentation is a process that proceeds without oxygen.Such a process can be described as ________.

Question 56

In every physical or chemical change,the universe tends toward greater disorder.This is the ________ law of thermodynamics,or the law of thermodynamic ________.

Question 57

________ reactions release energy when electrons are removed from a substance.

Question 58

You wish to use a bioluminescent marker to follow the movement of a particular protein through a eukaryotic cell.How would you design your experiment to allow you to visualize this movement,and where would you expect to see your protein?

Question 59

Within biological systems,there are always reactions that seem to occur when thermodynamically they should not.An example is in the process of glycolysis,ΔG°' = 2183.6 kJ/mol.How is this possible,when cells are governed by the laws of thermodynamics?