Question 1

Coupled reactions are important components of human physiology. Describe an example of a coupled reaction in the human body.

Accepted Answer

A coupled reaction is when an exergonic

Question 2

When certain molecules are pumped across biological membranes against a concentration gradient via active transport, ATP is used. In our body cells, for example, sugars are actively transported and metabolized within the membrane-enclosed mitochondria. Prokaryotes, in contrast, lack mitochondria but are nonetheless able to metabolize the same sugars. Based on the details provided in this scenario, which of the following statements is expected to be TRUE?

Accepted Answer

A) The sugar-digesting enzymes in eukaryotic cells, such as sucrase, are not the same sugar-digesting enzymes found in prokaryotic cells. 
B) Overall, prokaryotes will gain more ATP per sugar molecule metabolized than will eukaryotes. 
C) Prokaryotes and eukaryotes should have the same metabolic efficiency when digesting the same sugars, assuming their enzymes are the same. 
D) Sugar metabolism in prokaryotes is exergonic, whereas in eukaryotes it is endergonic. 
A) The sugar-digesting enzymes in eukaryotic cells, such as sucrase, are not the same sugar-digesting enzymes found in prokaryotic cells. 
B) Overall, prokaryotes will gain more ATP per sugar molecule metabolized than will eukaryotes. 
C) Prokaryotes and eukaryotes should have the same metabolic efficiency when digesting the same sugars, assuming their enzymes are the same. 
D) Sugar metabolism in prokaryotes is exergonic, whereas in eukaryotes it is endergonic.

Question 3

If this figure shows the metabolism of glucose and oxygen to CO2 and H2O, where do the carbon in CO2 and the hydrogen in H2O come from?

Accepted Answer

A) glucose 
B) the products of the reaction 
C) the activation energy of the reaction 
D) the catalyst 
A) glucose 
B) the products of the reaction 
C) the activation energy of the reaction 
D) the catalyst

Question 4

The second law of thermodynamics states that the ________, or disorder, of the universe is constantly increasing.

Accepted Answer

The answer of The second law of thermodynamics states that...

Question 5

During photosynthesis, plants convert light energy to chemical energy. This is an example of:

Accepted Answer

A) increasing entropy. 
B) chemical equilibrium. 
C) the first law of thermodynamics. 
D) the second law of thermodynamics. 
E) a spontaneous reaction. 
A) increasing entropy. 
B) chemical equilibrium. 
C) the first law of thermodynamics. 
D) the second law of thermodynamics. 
E) a spontaneous reaction.

Question 6

Which molecule functions in the short-term storage of energy?

Accepted Answer

A) glycogen 
B) fat 
C) sucrose 
D) adenosine triphosphate 
E) protein 
A) glycogen 
B) fat 
C) sucrose 
D) adenosine triphosphate 
E) protein

Question 7

Briefly explain the two laws of thermodynamics.

Accepted Answer

The law of the conservation of energy st

Question 8

Describe the biochemical properties of a biological catalyst.

Accepted Answer

Catalysts (enzymes)speed up on

Question 9

The end product of a biosynthetic pathway often acts to block the initial step in that pathway. This phenomenon is called:

Accepted Answer

A) allosteric activation. 
B) denaturation. 
C) irreversible inhibition. 
D) feedback inhibition. 
E) substrate activation. 
A) allosteric activation. 
B) denaturation. 
C) irreversible inhibition. 
D) feedback inhibition. 
E) substrate activation.

Question 10

The burning of sugars as fuels for runners is an example of an ________ chemical reaction, whereas the production of sugars during photosynthesis is an example of an ________ chemical reaction.

Accepted Answer

exergonic;

Question 11

Imagine you are conducting an experiment on an enzyme known as sucrase. This enzyme is synthesized and used by yeast cells to break down the disaccharide sucrose (table sugar)into the monosaccharides glucose and fructose. You decide to conduct an experiment to test whether the sucrase enzyme can break down the artificial sweetener sucralose. Sucralose (a "chlorinated" carbohydrate)has some chemical similarity to sucrose, but is different in that three of its hydroxyl groups are missing and replaced with chlorine atoms instead. Based on the details provided in this scenario, do you think the sucrase enzyme will be able to interact with sucralose?

Accepted Answer

A) Yes; enzymes such as sucrase are not specific for their substrate. 
B) No; all enzymes are highly specific and can react with only a specific substrate. 
C) No; sucralose is an ion and not a true carbohydrate. 
D) Yes; the enzymes in human cells can interact with artificial sweeteners as if they were sugars. 
A) Yes; enzymes such as sucrase are not specific for their substrate. 
B) No; all enzymes are highly specific and can react with only a specific substrate. 
C) No; sucralose is an ion and not a true carbohydrate. 
D) Yes; the enzymes in human cells can interact with artificial sweeteners as if they were sugars.

Question 12

Coenzymes function by:

Accepted Answer

A) helping the enzyme reconfigure the substrate molecules. 
B) binding to the substrate and weakening the bonds of the enzyme. 
C) binding two or more substrates together. 
D) helping substrates find enzymes. 
E) joining together to form an enzyme. 
A) helping the enzyme reconfigure the substrate molecules. 
B) binding to the substrate and weakening the bonds of the enzyme. 
C) binding two or more substrates together. 
D) helping substrates find enzymes. 
E) joining together to form an enzyme.

Question 13

In exergonic chemical reactions:

Accepted Answer

A) the reactants have more energy than the products. 
B) energy is stored by the reactions. 
C) the reactants have less energy than the products. 
D) the reactants and products possess equal amounts of energy. 
A) the reactants have more energy than the products. 
B) energy is stored by the reactions. 
C) the reactants have less energy than the products. 
D) the reactants and products possess equal amounts of energy.

Question 14

Compare endergonic and exergonic chemical reactions using an analogy from everyday life.

Accepted Answer

There are many possible examples: Rollin

Question 15

Why is photosynthesis considered an endergonic reaction?

Accepted Answer

A) Activation energy is not required. 
B) Photosynthesis does not comply with the physical laws of the universe. 
C) Sugar has less energy than the sun. 
D) Protein catalysts are not needed. 
E) Low-energy reactants are converted to high-energy products. 
A) Activation energy is not required. 
B) Photosynthesis does not comply with the physical laws of the universe. 
C) Sugar has less energy than the sun. 
D) Protein catalysts are not needed. 
E) Low-energy reactants are converted to high-energy products.

Question 16

In an isolated system, all of the following are true of the second law of thermodynamics EXCEPT:

Accepted Answer

A) the amount of useful energy decreases. 
B) spontaneous changes result in a more uniform distribution of energy. 
C) all chemical reactions release more energy than they consume. 
D) there is a natural tendency toward greater disorder of the organization of matter. 
A) the amount of useful energy decreases. 
B) spontaneous changes result in a more uniform distribution of energy. 
C) all chemical reactions release more energy than they consume. 
D) there is a natural tendency toward greater disorder of the organization of matter.

Question 17

Triclosan is a broad-spectrum antibacterial agent used in many household products. It is structurally similar to polychlorobiphenylol, a substrate that binds to the active site of the enzyme sulfotransferase. Based on these facts, you can conclude that triclosan most likely:

Accepted Answer

A) lowers the activation energy of chemical reactions. 
B) functions as an enzyme when sulfotransferase is absent. 
C) is a competitive inhibitor. 
D) acts as a noncompetitive inhibitor. 
A) lowers the activation energy of chemical reactions. 
B) functions as an enzyme when sulfotransferase is absent. 
C) is a competitive inhibitor. 
D) acts as a noncompetitive inhibitor.

Question 18

An ________ chemical reaction releases energy, whereas an ________ reaction requires an input of energy.

Accepted Answer

A) exergonic; endergonic 
B) endergonic; exergonic 
C) enzymatic; endergonic 
D) endergonic; enzymatic 
E) equilibrium; exergonic 
A) exergonic; endergonic 
B) endergonic; exergonic 
C) enzymatic; endergonic 
D) endergonic; enzymatic 
E) equilibrium; exergonic

Question 19

The addition of the competitive inhibitor slows down a particular reaction. How could you overcome the effects of the inhibitor and increase the rate of the reaction?

Accepted Answer

A) add more inhibitor 
B) add more substrate 
C) lower the temperature of the reaction 
D) add a coenzyme 
E) allow the reaction to reach equilibrium 
A) add more inhibitor 
B) add more substrate 
C) lower the temperature of the reaction 
D) add a coenzyme 
E) allow the reaction to reach equilibrium

Question 20

Explain how enzymes decrease the activation energy required for biological processes in our bodies.

Accepted Answer

Enzymes decrease the activatio

Exam 6: Energy Flow in the Life of a Cell

Coupled reactions are important components of human physiology. Describe an example of a coupled reaction in the human body.

If this figure shows the metabolism of glucose and oxygen to CO2 and H2O, where do the carbon in CO2 and the hydrogen in H2O come from?

The second law of thermodynamics states that the ________, or disorder, of the universe is constantly increasing.

During photosynthesis, plants convert light energy to chemical energy. This is an example of:

Which molecule functions in the short-term storage of energy?

Briefly explain the two laws of thermodynamics.

Describe the biochemical properties of a biological catalyst.

The end product of a biosynthetic pathway often acts to block the initial step in that pathway. This phenomenon is called:

The burning of sugars as fuels for runners is an example of an ________ chemical reaction, whereas the production of sugars during photosynthesis is an example of an ________ chemical reaction.

Coenzymes function by:

In exergonic chemical reactions:

Compare endergonic and exergonic chemical reactions using an analogy from everyday life.

Why is photosynthesis considered an endergonic reaction?

In an isolated system, all of the following are true of the second law of thermodynamics EXCEPT:

Triclosan is a broad-spectrum antibacterial agent used in many household products. It is structurally similar to polychlorobiphenylol, a substrate that binds to the active site of the enzyme sulfotransferase. Based on these facts, you can conclude that triclosan most likely:

An ________ chemical reaction releases energy, whereas an ________ reaction requires an input of energy.

The addition of the competitive inhibitor slows down a particular reaction. How could you overcome the effects of the inhibitor and increase the rate of the reaction?

Explain how enzymes decrease the activation energy required for biological processes in our bodies.

An Introduction to Life on Earth

Atoms, Molecules, and Life

Biological Molecules

Cell Structure and Function

Cell Membrane Structure and Function

Capturing Solar Energy: Photosynthesis

Harvesting Energy: Glycolysis and Cellular Respiration

The Continuity of Life: Cellular Reproduction

Patterns of Inheritance

Dna: the Molecule of Heredity

Gene Expression and Regulation

Biotechnology

Principles of Evolution

How Populations Evolve

The Origin of Species

The History of Life

Systematics: Seeking Order Amidst Diversity

The Diversity of Prokaryotes and Viruses

The Diversity of Protists

The Diversity of Plants

The Diversity of Fungi

Animal Diversity I: Invertebrates

Animal Diversity Ii: Vertebrates

Animal Behavior

Population Growth and Regulation

Community Interactions

How Do Ecosystems Work

Earths Diverse Ecosystems

Conserving Earths Biodiversity

Homeostasis and the Organization of the Animal Body

Circulation

Respiration

Nutrition and Digestion

The Urinary System

Defenses Against Disease

Chemical Control of the Animal Body: the Endocrine System

The Nervous System

The Senses

Action and Support: the Muscles and Skeleton

Animal Reproduction

Animal Development

Plant Anatomy and Nutrient Transport

Plant Reproduction and Development

Plant Responses to the Environment

Filters

The burning of sugars as fuels for runners is an example of an chemical reaction, whereas the production of sugars during photosynthesis is an example of an chemical reaction.

An chemical reaction releases energy, whereas an reaction requires an input of energy.