Active Lecture Questions Copyright © 2011 Pearson Education Inc. Chapter 6 Energy Flow in the Life of a Cell

Copyright © 2011 Pearson Education Inc.Biology: Life on Earth, 9e Energy is the capacity to do work, and work causes an object to move. When a plant is undergoing photosynthesis, what, in particular, is moving? 1.Neutrons 2.Protons 3.Electrons 4.Electron-carrier FADH 2

Copyright © 2011 Pearson Education Inc.Biology: Life on Earth, 9e Energy is the capacity to do work, and work causes an object to move. When a plant is undergoing photosynthesis, what, in particular, is moving? 1.Neutrons 2.Protons 3.Electrons 4.Electron-carrier FADH 2

Copyright © 2011 Pearson Education Inc.Biology: Life on Earth, 9e Why do you get hot when you work out? 1.Muscles are broken down and heat up when you workout. 2.All the chemical energy in food is directly converted to the energy of heat. 3.As the energy in food is converted to the energy of movement, all the energy is converted to heat. 4.As the energy in food is converted to the energy of movement, some of the original energy is converted to heat.

Copyright © 2011 Pearson Education Inc.Biology: Life on Earth, 9e Why do you get hot when you work out? 1.Muscles are broken down and heat up when you workout. 2.All the chemical energy in food is directly converted to the energy of heat. 3.As the energy in food is converted to the energy of movement, all the energy is converted to heat. 4.As the energy in food is converted to the energy of movement, some of the original energy is converted to heat.

Copyright © 2011 Pearson Education Inc.Biology: Life on Earth, 9e If energy is given off in a reaction, you can assume that: 1.It is an endergonic reaction. 2.It is an exergonic reaction. 3.Entropy is decreasing. 4.The laws of thermodynamics have been defied.

Copyright © 2011 Pearson Education Inc.Biology: Life on Earth, 9e If energy is given off in a reaction, you can assume that: 1.It is an endergonic reaction. 2.It is an exergonic reaction. 3.Entropy is decreasing. 4.The laws of thermodynamics have been defied.

Copyright © 2011 Pearson Education Inc.Biology: Life on Earth, 9e Photosynthesis and cellular respiration are considered “opposite” reactions. Which of the following DOES NOT support this concept? 1.Photosynthesis is exergonic, while cellular respiration is endergonic. 2.The products of one are the reactants of the other. 3.The reactants of one are the products of the other. 4.One needs an input of energy, and the other gives off energy.

Copyright © 2011 Pearson Education Inc.Biology: Life on Earth, 9e Photosynthesis and cellular respiration are considered “opposite” reactions. Which of the following DOES NOT support this concept? 1.Photosynthesis is exergonic, while cellular respiration is endergonic. 2.The products of one are the reactants of the other. 3.The reactants of one are the products of the other. 4.One needs an input of energy, and the other gives off energy.

Copyright © 2011 Pearson Education Inc.Biology: Life on Earth, 9e How is ATP used to fuel muscles in a runner? 1.The exergonic reaction of ATP breakdown is coupled with endergonic reactions that power muscle movement. 2.The endergonic reaction of ATP breakdown is coupled with exergonic reactions used to fuel muscle movement. 3.ATP forms glucose in a chain reaction, and glucose directly fuels muscle movement. 4.Glucose and other sugar molecules are broken down into lactic acid, which fuels muscle movement.

Copyright © 2011 Pearson Education Inc.Biology: Life on Earth, 9e How is ATP used to fuel muscles in a runner? 1.The exergonic reaction of ATP breakdown is coupled with endergonic reactions that power muscle movement. 2.The endergonic reaction of ATP breakdown is coupled with exergonic reactions used to fuel muscle movement. 3.ATP forms glucose in a chain reaction, and glucose directly fuels muscle movement. 4.Glucose and other sugar molecules are broken down into lactic acid, which fuels muscle movement.

Copyright © 2011 Pearson Education Inc.Biology: Life on Earth, 9e What is metabolism? 1.Heat energy given off during chemical reactions 2.The sum of all the biochemical reactions in a cell 3.The amount of energy that can be consumed by an organism 4.The amount of heat given off by a cell

Copyright © 2011 Pearson Education Inc.Biology: Life on Earth, 9e What is metabolism? 1.Heat energy given off during chemical reactions 2.The sum of all the biochemical reactions in a cell 3.The amount of energy that can be consumed by an organism 4.The amount of heat given off by a cell

Copyright © 2011 Pearson Education Inc.Biology: Life on Earth, 9e Which homeostatic process helps us maintain a constant body temperature? 1.Heat from energy captured from the sun is held in our cells. 2.We have to warm our bodies by sitting in the sun. 3.Heat that is given off as energy during metabolic activity in cells is used to stabilize body temperature. 4.Heat energy is captured, when ADP and a phosphate group capture kinetic energy from metabolic reactions.

Copyright © 2011 Pearson Education Inc.Biology: Life on Earth, 9e Which homeostatic process helps us maintain a constant body temperature? 1.Heat from energy captured from the sun is held in our cells. 2.We have to warm our bodies by sitting in the sun. 3.Heat that is given off as energy during metabolic activity in cells is used to stabilize body temperature. 4.Heat energy is captured, when ADP and a phosphate group capture kinetic energy from metabolic reactions.

Copyright © 2011 Pearson Education Inc.Biology: Life on Earth, 9e Why wouldn’t the enzyme that breaks down maltose break down lactose as well? 1.The enzyme that breaks down maltose has a specifically shaped active site, and lactose won’t fit. 2.The enzyme that facilitates the breakdown of maltose is used up in the reaction that breaks down this sugar into its subunits. 3.The sequence of monosaccharides that make up the enzyme allow only one substrate to bind to one specifically shaped enzyme. 4.It would. The enzymes do have the ability to break down any kind of sugar.

Copyright © 2011 Pearson Education Inc.Biology: Life on Earth, 9e Why wouldn’t the enzyme that breaks down maltose break down lactose as well? 1.The enzyme that breaks down maltose has a specifically shaped active site, and lactose won’t fit. 2.The enzyme that facilitates the breakdown of maltose is used up in the reaction that breaks down this sugar into its subunits. 3.The sequence of monosaccharides that make up the enzyme allow only one substrate to bind to one specifically shaped enzyme. 4.It would. The enzymes do have the ability to break down any kind of sugar.

Copyright © 2011 Pearson Education Inc.Biology: Life on Earth, 9e In feedback mechanisms, the final product of a metabolic pathway inhibits activity at the beginning of the pathway. This reduces production of the final product when its levels are too high. How does this work? 1.The final product competes for an allosteric site of one of the first substrates in the metabolic pathway. 2.The final product binds to an allosteric site of an enzyme at the beginning of the metabolic pathway. 3.The allosteric site of the product binds to the enzyme at the beginning of the metabolic pathway. 4.The reaction knows to shut down when there is too much enzyme produced in the final reaction.

Copyright © 2011 Pearson Education Inc.Biology: Life on Earth, 9e In feedback mechanisms, the final product of a metabolic pathway inhibits activity at the beginning of the pathway. This reduces production of the final product when its levels are too high. How does this work? 1.The final product competes for an allosteric site of one of the first substrates in the metabolic pathway. 2.The final product binds to an allosteric site of an enzyme at the beginning of the metabolic pathway. 3.The allosteric site of the product binds to the enzyme at the beginning of the metabolic pathway. 4.The reaction knows to shut down when there is too much enzyme produced in the final reaction.

Copyright © 2011 Pearson Education Inc.Biology: Life on Earth, 9e How do some cancer drugs limit the growth of cancerous cells? 1.They kill the cancer cell’s enzymes. 2.They compete with the RNA for the production of a messenger producing defective DNA. 3.They compete with DNA nucleotides for the active site of the DNA-building enzyme, producing defective DNA. 4.They compete with DNA nucleotides for the active site of the final product, producing defective DNA.

Copyright © 2011 Pearson Education Inc.Biology: Life on Earth, 9e How do some cancer drugs limit the growth of cancerous cells? 1.They kill the cancer cell’s enzymes. 2.They compete with the RNA for the production of a messenger producing defective DNA. 3.They compete with DNA nucleotides for the active site of the DNA-building enzyme, producing defective DNA. 4.They compete with DNA nucleotides for the active site of the final product, producing defective DNA.

Copyright © 2011 Pearson Education Inc.Biology: Life on Earth, 9e Why is having a high fever dangerous? 1.The rise in temperature changes the shape of enzyme active sites, preventing the binding of specifically shaped substrates. 2.The rise in temperature changes the shape of substrate active sites, preventing the binding of specifically shaped enzymes. 3.High temperatures can destroy the structure of ATP, leaving no fuel for metabolic reactions. 4.High temperatures cause exergonic reactions that release energy as heat to become endergonic reactions that hold heat.

Copyright © 2011 Pearson Education Inc.Biology: Life on Earth, 9e Why is having a high fever dangerous? 1.The rise in temperature changes the shape of enzyme active sites, preventing the binding of specifically shaped substrates. 2.The rise in temperature changes the shape of substrate active sites, preventing the binding of specifically shaped enzymes. 3.High temperatures can destroy the structure of ATP, leaving no fuel for metabolic reactions. 4.High temperatures cause exergonic reactions that release energy as heat to become endergonic reactions that hold heat.

Copyright © 2011 Pearson Education Inc.Biology: Life on Earth, 9e When a muscle cell demands energy to perform the work of contraction, what happens to ATP? 1.ATP manufactures more ATP. 2.ATP is built up. 3.ATP catalyzes the reaction. 4.ATP is broken down.

Copyright © 2011 Pearson Education Inc.Biology: Life on Earth, 9e When a muscle cell demands energy to perform the work of contraction, what happens to ATP? 1.ATP manufactures more ATP. 2.ATP is built up. 3.ATP catalyzes the reaction. 4.ATP is broken down.

Copyright © 2011 Pearson Education Inc.Biology: Life on Earth, 9e Lactose intolerance is caused by: 1.The inability of lactose to bind to the active site of the enzyme lactase. 2.The change in shape of lactase’s active site and the inability of lactose to bind. 3.The inability of an individual to synthesize the enzyme (lactase) that digests lactose. 4.The substitution of glucose for lactose in cellular respiration.

Copyright © 2011 Pearson Education Inc.Biology: Life on Earth, 9e Lactose intolerance is caused by: 1.The inability of lactose to bind to the active site of the enzyme lactase. 2.The change in shape of lactase’s active site and the inability of lactose to bind. 3.The inability of an individual to synthesize the enzyme (lactase) that digests lactose. 4.The substitution of glucose for lactose in cellular respiration.

Copyright © 2011 Pearson Education Inc.Biology: Life on Earth, 9e When a molecule that is not the normal substrate for an enzyme binds to its active site, this results in: 1.Competitive inhibition. 2.Noncompetitive inhibition. 3.Feedback inhibition. 4.Allosteric inhibition.

Copyright © 2011 Pearson Education Inc.Biology: Life on Earth, 9e When a molecule that is not the normal substrate for an enzyme binds to its active site, this results in: 1.Competitive inhibition. 2.Noncompetitive inhibition. 3.Feedback inhibition. 4.Allosteric inhibition.

Copyright © 2011 Pearson Education Inc.Biology: Life on Earth, 9e Figure 6-15a If extracellular pH were more acidic, the blue line in the figure below would: 1.Remain where it is. 2.Be farther to the right. 3.Be farther to the left. 4.Be more in the alkaline range.

Copyright © 2011 Pearson Education Inc.Biology: Life on Earth, 9e If extracellular pH were more acidic, the blue line in the figure below would: 1.Remain where it is. 2.Be farther to the right. 3.Be farther to the left. 4.Be more in the alkaline range. Figure 6-15a