Deck 4: The Energy of Life

Question 1

Coupled reactions are reactions in which a

A) exergonic reaction drives an endergonic reaction.
B) exergonic reaction drives a spontaneous reaction.
C) endergonic reaction drives an exergonic reaction.
D) endergonic reaction drives a spontaneous reaction.

Answer 1

A

Question 2

Entropy is a measure of

A) complexity.
B) disorder.
C) order.
D) kinetic energy.
E) potential energy.

Answer 2

B

Question 3

An enzyme is

A) always a protein.
B) an organic molecule that catalyzes a cellular reaction.
C) not necessary to sustain life in a cell.
D) used up in a reaction.
E) All of the answer choices are correct.

Answer 3

B

Question 4

An endergonic reaction is a reaction that is characterized by

A) yielding larger product molecules than the original reactants.
B) yielding smaller product molecules than the original reactants.
C) having products with lower energy than the reactants.
D) having products with higher energy than the reactants.
E) often having higher energy in product molecules than the reactants, and yielding larger product molecules.

Question 5

Oxidation means

A) the loss of electrons from a molecule.
B) the loss of oxygen by a cell.
C) the gain of electrons by a molecule.
D) the gain of oxygen by a cell.

Question 6

At chemical equilibrium

A) there are no more products being formed.
B) the amount of reactants is equal to the amount of products.
C) reaction rates are in balance.
D) there are no more reactants for the cell to utilize.
E) no reactions are occurring in either direction.

Question 7

The amount of energy required to raise the temperature of one kilogram of water by 1° Celsius is a

A) joule.
B) kilocalorie.
C) calorie.
D) measure of density.
E) None of the answer choices are correct.

Question 8

Reduction means

A) the loss of electrons by a molecule.
B) the gain of electrons by a molecule.
C) the loss of oxygen from a cell.
D) the gain of oxygen by a cell.

Question 9

Each protein in an electron transport chain is sequentially oxidized,then reduced,allowing the work of actively transporting oxygen molecules by active membrane transport.

Question 10

An example (or examples)of potential energy is (are)

A) light and chemical bonds.
B) concentration gradients.
C) chemical bonds and concentration gradients.
D) chemical bonds.
E) light.

Question 11

The metabolic rate of individuals is influenced by

A) the amount of body fat.
B) the amount of thyroxin produced by the thyroid.
C) age.
D) All of the answer choices are correct.
E) weight.

Question 12

You are cold.Your body begins a shivering response.You quickly rub your hands together,and the friction produces a small amount of heat.The heat is evidence of increasing entropy.

Question 13

Oxidation-reduction reactions

A) transfer electrons from one molecule to another.
B) increase the amount of oxygen in the cell.
C) transfer protons from one molecule to another.
D) are not used by living cells.
E) reduce the amount of oxygen in the cell.

Question 14

The breakdown of glucose to carbon dioxide and water is an

A) exergonic reaction in photosynthesis.
B) exergonic reaction in cellular respiration.
C) endergonic reaction in photosynthesis.
D) endergonic reaction in cellular respiration.

Question 15

The process of phosphorylation

A) adds a phosphate group to a molecule.
B) removes a phosphate group from a molecule.
C) may change the shape of the target molecule.
D) All of the answer choices are correct.
E) may energize the target molecule.

Question 16

Which of the following is not an example of kinetic energy?

A) sound
B) light
C) heat
D) the energy in chemical bonds
E) random molecular movement

Question 17

A serving of 30 grams of almonds may have 190 Calories listed on a nutrition label.This represents

A) enough energy to raise the temperature of 190 grams of water 1 °C.
B) enough energy to raise the temperature of 30 grams of water 190 °C.
C) enough energy to raise the temperature of 30 kilograms of water 190 °C.
D) enough energy to raise the temperature of 190 kilograms of water 1 °C.

Question 18

Which statement is not part of the first law of thermodynamics?

A) The amount of energy in the universe is constant.
B) None of the answer choices are correct.
C) Energy cannot be created or destroyed.
D) Energy can be converted to other forms of energy.
E) Any energy transformation loses some energy to its surroundings as heat.

Question 19

A raw peanut having almost 2 Calories of energy has 2,000 times the energy to raise the temperature of 1 gram water by 1 °C.

Question 20

Oxidation-reduction reactions

A) remove protons from one molecule and join them to another molecule.
B) remove electrons from both molecules involved.
C) remove oxygen from the cell.
D) never occur at the same time.
E) occur simultaneously.

Question 21

Simple diffusion

A) does not require energy.
B) utilizes proteins to move molecules across a membrane.
C) requires energy.
D) cannot occur without a membrane present.
E) moves molecules against a concentration gradient.

Question 22

If the environment surrounding a cell has a lower concentration of solute than the cell,the

A) environment is hypotonic to the cell.
B) environment is isotonic to the cell.
C) cell will not experience a net gain or loss of water.
D) environment is hypertonic to the cell.
E) cell will die.

Question 23

Noncompetitive inhibition of enzymes occurs

A) when a cofactor, instead of a reactant, binds to the enzyme active site.
B) when a substance binds to an enzyme at a site away from the active site.
C) by blocking the production of an enzyme.
D) when a substance other than the substrate binds at the active site of an enzyme.

Question 24

Much medical advice towards heart health indicates that you should eat less sodium (table salt).Notable higher risks of high sodium may include high blood pressure and damage to arteries or organs in your body.If you eat a single meal with large amounts of salt to suit your taste,which of these may result within minutes,as the sodium enters your bloodstream?

A) Simple diffusion of water and sodium will both balance in an isotonic condition between arteries and body tissues.
B) You should expect no change in the concentration gradient because of a single meal, rather than lifestyle and diet.
C) Your blood will become hypotonic, and water in your body tissues will flow into your arteries, inflating them.
D) Your blood will become hypertonic, and water in your body tissues will flow into your arteries, inflating them.

Question 25

Enzymes speed chemical reactions by

A) supplying energy to the reaction process.
B) raising the temperature of the surroundings.
C) lowering the amount of reactants that are needed.
D) lowering the energy required to start a chemical reaction.
E) maintaining chemical equilibrium.

Question 26

Determine which of these statements best summarizes the cellular regulation of concentration gradients.

A) Enzymes are used in the cell to build molecules on one side of membranes to establish concentration gradients.
B) Passive and active transport both function when vesicles transport materials across the cell membranes.
C) Membrane phospholipids and proteins regulate transport functions to establish concentration gradients or equilibria.
D) Selective permeability of the cell membranes results in equal amounts of substances inside and outside the cell.

Question 27

Figuer:
This diagram shows the basic structure and function of an enzyme, acting to catalyze a cell's chemical reaction.
The region of an enzyme that catalyzes reactions is called a(n)

A) active site.
B) binding pocket.
C) catalyst site.
D) reaction site.
E) cofactor site.

Question 28

A cell produces proteins when ribosomes (a form of RNA and protein)and transfer RNA (tRNA)work together.Specific amino acids are brought by tRNA into the ribosome,where they are rapidly connected by covalent bonds.This indicates that ribosomes are acting as

A) active sites.
B) substrates.
C) reactants.
D) enzymes.

Question 29

Competitive inhibition of enzymes occurs

A) when a substance binds to an enzyme at a site away from the active site.
B) when the product, instead of the reactant of a reaction binds to the active site.
C) when a substance other than the substrate binds at the active site of an enzyme.
D) when the product, or other substances, instead of the reactant, bind to the active site of the enzyme.
E) by blocking the production of an enzyme.

Question 30

Active transport is different from simple diffusion in that active transport

A) moves molecules against a concentration gradient.
B) All of the answer choices are correct.
C) requires proteins embedded within the cell membrane.
D) requires energy.
E) moves molecules from an area of lower concentration to an area of higher concentration.

Question 31

Cofactors,required for correct action of enzymes,are often in our diets as vitamins,minerals,and coenzymes.

Question 32

Phagocytosis of an infective bacterium by a white blood cell is a subset type of

A) exocytosis.
B) facilitated diffusion.
C) simple diffusion.
D) endocytosis.

Question 33

Turgor pressure in plant cells is

A) a result of the walled cell being in a hypotonic environment.
B) due in part to osmosis.
C) necessary to keep plants from wilting.
D) the force of water against the inside of the cell wall.
E) All of the answer choices are correct.

Question 34

If a cell has a 95% concentration of water in its cytoplasm and the environment surrounding the cell has a 90% concentration of water,water will flow

A) into the cell by osmosis.
B) out of the cell by active transport.
C) out of the cell by osmosis.
D) into the cell by active transport.
E) into the cell by facilitated diffusion.

Question 35

Which of the following are examples of kinetic energy?

A) electrons in chemical bonds of the food molecules, proton gradients established, ATP molecules
B) protons moving through ATPase by facilitated diffusion, ATP molecules
C) electrons from food molecules moving through electron transport chain, proton gradients established
D) electrons from food molecules moving through the electron transport chain, and protons moving through ATPase

Question 36

If a cell has a greater concentration of solute than its environment,the cell

A) will not experience a net gain or loss of water.
B) is hypertonic to the environment.
C) will die.
D) is isotonic to the environment.
E) is hypotonic to the environment.

Question 37

The diffusion of water across a selectively permeable (biological)membrane is

A) osmosis.
B) active transport.
C) always beneficial to a cell.
D) a rare occurrence.
E) a process that always requires proteins.

Question 38

Figuer:
This diagram shows the basic structure and function of an enzyme, acting to catalyze a cell's chemical reaction.
The molecule that fits into the active site of an enzyme and reacts with the enzyme is

A) an analog.
B) a substrate.
C) always a carbohydrate.
D) always broken down by the enzyme.
E) always a protein.

Question 39

Which of the following are examples of potential energy associated with our food consumption and metabolism?

A) electrons in chemical bonds of food molecules, proton gradients, and ATP molecules
B) electrons moving through the electron transport chain, and protons moving through ATPase
C) protons moving through ATPase by facilitated diffusion, ATP molecules
D) All of the answer choices are correct.
E) electrons from food molecules moving through the electron transport chain, and a proton gradient

Question 40

When electrons are removed from a food molecule it is

A) an exergonic reaction.
B) an endergonic reaction.
C) in equilibrium.
D) being reduced.
E) being oxidized.

Question 41

CFTR moves chloride ions out of cells by active transport.What can be inferred from this statement?

A) Normal initial chloride concentrations are lower on the inside of the cell.
B) Normal resulting chloride concentrations are higher on the outside of the cell.
C) CFTR functions as the cystic fibers attach to and pull chlorides through holes in the membrane.
D) Water will also cross the membrane, with the chlorides, through the CFTR proteins.

Question 42

After the active transport of chloride ions out of the cell by CFTR,why does water follow by osmosis?

A) The cell is now in a hypotonic solution.
B) The cell must pump out water to avoid bursting.
C) The cell is now in a hypertonic solution.
D) The cell needs to regenerate the ATP used in active transport.
E) The cell is now in an isotonic solution.

Question 43

For animals and other organisms consuming food,the molecular reactants to cellular respiration are

A) carbon dioxide and water.
B) entropy.
C) digestive enzymes.
D) glucose and oxygen.

Question 44

During low tide a plant cell will have an advantage over an animal cell because of its

A) chloroplasts.
B) nucleus.
C) cell wall.
D) plasma membrane.
E) mitochondria.

Question 45

The CFTR is a normal membrane protein used to move chloride ions out of a cell by active transport.This is an example of

A) a reaction coupled with the production of ATP.
B) equilibrium.
C) a reaction coupled with the hydrolysis of ATP.
D) a reduction reaction.
E) an oxidation reaction.

Question 46

If a person is poisoned with cyanide,they cannot generate ATP,and die within a few minutes.In relation to the sodium-potassium pump,what specific impact would cyanide have on concentrations across the cell membrane?

A) Sodium and potassium concentrations would both be higher inside the cell.
B) Both sodium and potassium concentrations would become isotonic outside the cell.
C) Sodium concentration would be higher outside the cell, while potassium concentration would be higher inside the cell.
D) Sodium and potassium concentrations would both be higher outside the cell.
E) Both sodium and potassium concentrations would reach equilibrium conditions across the cell membrane.

Question 47

Simple diffusion occurs naturally as it ___ of a system.

A) decreases the kinetic energy
B) increases the potential energy
C) decreases the equilibrium
D) increases the entropy
E) All of the answer choices are correct.

Question 48

At high tide a coastal plant or animal cell will be in

A) equilibrium.
B) osmosis.
C) a hypertonic solution.
D) a hypotonic solution.
E) an isotonic solution.

Question 49

Once ATP donates its phosphate to a coupled reaction it becomes ADP.The ADP

A) can be recharged in an exergonic reaction to form ATP.
B) is a waste product that must be broken down.
C) can be recharged in an endergonic reaction to form ATP.
D) becomes the needed potential energy source for another coupled reaction.
E) can be recharged in an oxidation reaction to form ATP.

Question 50

The molecular reactants for photosynthesis are

A) glucose and carbon dioxide.
B) glucose and sunlight.
C) organic compounds.
D) glucose and water.
E) water and carbon dioxide.

Question 51

Firewood is made up of cellulose,which is a polymer of glucose molecules.When burning,heat and light are given off,indicating that a(n)________ reaction is occurring.

A) endergonic
B) equilibrium
C) exergonic
D) potential energy
E) kinetic energy

Question 52

A bowl of sugar water is very stable.In a cell,however,it is rapidly broken down into carbon dioxide and water,releasing stored energy.What is the best explanation for this observation?

A) Glucose becomes more chemically reactive inside of a cell.
B) Cells use energy to break down the glucose.
C) Glucose is only broken down while dissolving into a watery solution, such as inside the cell.
D) Glucose cannot be broken down outside of a cell.
E) Enzymes in the cell catalyze the breakdown of the glucose.

Question 53

One way to produce a vaccine is to heat a virus or bacteria and then inject the inactive pathogen as a vaccination.How would the heat inactivate a virus?

A) by denaturing proteins
B) All of the answer choices are correct.
C) by inhibiting its metabolism
D) by blocking facilitated diffusion
E) by destroying the membrane

Question 54

If you drop a rubber ball it doesn't bounce back to the height you dropped it from.This is consistent with

A) conversion of kinetic energy into entropy.
B) conversion of entropy into potential energy.
C) the first law of thermodynamics.
D) the second law of thermodynamics.
E) conversion of kinetic energy into potential energy.

Question 55

The sodium-potassium pump catalyzes

A) equilibrium.
B) facilitated diffusion.
C) osmosis.
D) active transport.
E) diffusion.

Question 56

Figuer:
This diagram summarizes energy transfers and molecule exchanges among plants and animals, as you will learn later we call producers and consumers.
Plants require energy to perform photosynthesis,in which glucose is formed from carbon dioxide and water,and stores energy.This is a(n)_____ reaction.

A) kinetic energy
B) exergonic
C) endergonic
D) potential energy
E) equilibrium

Question 57

Your liver produces 90% of the cholesterol found in your body.When cholesterol levels get too high,the first enzyme in the pathway of cholesterol synthesis is inhibited.This is an example of

A) positive feedback.
B) denaturation.
C) negative feedback.
D) equilibrium.
E) a coenzyme.

Question 58

The energy source that powers the process of photosynthesis is

A) oxygen.
B) glucose.
C) carbon dioxide.
D) water.
E) sunlight.

Question 59

Why does phenylalanine accumulate in patients with phenylketonuria?

A) They lack an enzyme to break down phenylalanine.
B) They produce too much phenylalanine.
C) They lack an enzyme to produce phenylalanine.
D) They lack an inhibitor of an enzyme to break down phenylalanine.

Question 60

During high tide a plant or animal would be at risk of

A) dehydration by facilitated diffusion of salts.
B) cells bursting due to active transport of salts.
C) dehydration by osmosis of water.
D) cells bursting by osmosis of water.
E) dehydration due to active transport of salts.

Question 61

Figuer:
What did the researchers conclude from the data shown in this figure?

A) The more cholera toxin an organism was exposed to, fewer copies of its CFTR gene that became defective.
B) The number of defective CFTR genes did not correlate with resistance to cholera toxin.
C) The fewer copies of a defective CFTR gene an organism has, the more resistant it is to cholera toxin.
D) The more copies of a defective CFTR gene an organism has, the more resistant it is to cholera toxin.
E) The more cholera toxin an organism was exposed to, the more copies of its CFTR gene that became defective.

Question 62

What hypothesis was tested by researcher Sherif Gabriel and his colleagues?

A) Does defective CFTR make people more sensitive to cholera?
B) Does cholera causes cystic fibrosis?
C) Does cholera increase the risk of transmission of cystic fibrosis?
D) Does defective CFTR give people natural resistance to cholera?

Question 63

An enzyme is a lipid that catalyzes chemical reactions.

Question 64

The first and second laws of thermodynamics apply to nonliving systems like gasoline engines but do not apply to reactions in living cells.

Question 65

Of these membrane transport processes,which do (does)not make use of a vesicle?

A) phagocytosis
B) facilitated diffusion
C) neither osmosis nor facilitated diffusion
D) pinocytosis
E) osmosis

Question 66

A reason that some antibiotics harm bacteria but not humans is because humans have many more cells than bacteria.

Question 67

One in 25 Caucasians is a carrier for the defective CFTR gene,making it the most common genetic disease in this population.Why would the frequency of defects in CFTR be so common in this population,given the relationship between cholera and CFTR is similar in humans?

A) Carriers with one copy of the defective CFTR gene have decreased resistance to cholera compared to those with no defective copies.
B) Carriers with one copy of the defective CFTR gene have increased resistance to cholera compared to those with no defective copies.
C) Only carriers would be able to survive exposure to cholera.
D) These individuals were exposed to cholera, causing mutations in their CFTR gene that can then be passed on to their children.
E) Carriers will be more likely to have children who develop cystic fibrosis.

Question 68

Movement of molecules down a concentration gradient is an example of

A) reduction.
B) kinetic energy.
C) active transport.
D) oxidation.
E) potential energy.

Question 69

Exergonic reactions do not require activation energy to get started.

Question 70

Figuer:
What is the dependent variable in the figure shown?

A) the number of defective copies of the CFTR gene in humans
B) the amount of fluid in the intestines after exposure to cholera toxin
C) whether or not the subjects were exposed to Vibrio cholera bacteria
D) whether or not the subjects were exposed to cholera toxin
E) the number of defective copies of the CFTR gene in mice

Question 71

Receptor-mediated endocytosis is a specialized,more selective method of cell membrane transport than pinocytosis.

Question 72

When an end product of a reaction pathway is in excess and inhibits the first enzyme of the pathway,this is an example of positive feedback.

Question 73

Whenever ATP is produced by a chemical reaction some energy is lost into the surroundings as heat.

Question 74

How does the bacteria that causes cholera,Vibrio cholera,trigger potentially life-threatening diarrhea?

A) Cholera toxin inhibits CFTR leading to decreased transport of water into the intestines.
B) Cholera toxin inhibits CFTR leading to increased transport of water into the intestines.
C) Cholera toxin stimulates CFTR leading to decreased transport of water into the intestines.
D) Cholera toxin stimulates CFTR leading to increased transport of water into the intestines.
E) Cholera toxin causes a DNA genetic mutation that modifies the function of CFTR proteins.

Question 75

Which of these membrane transport processes does not require membrane proteins?

A) active transport pumps
B) facilitated diffusion
C) endocytosis
D) osmosis

Question 76

Figuer:
What is the independent variable in the figure shown?

A) whether or not the subjects were exposed to cholera toxin
B) the amount of fluid in the intestines
C) whether or not the subjects were exposed to Vibrio cholera bacteria
D) the number of defective copies of the CFTR gene in humans
E) the number of defective copies of the CFTR gene in mice

Question 77

Phagocytosis is a process that cells use to move materials in through the cell membrane.

Question 78

Reduction is the gain of electrons by an atom or molecule.