Section 8-1 Energy and Life (pages 201-203). Key Concepts. • Where do plants get the energy they need to produce food? • What is the role of ATP in cellular.

• 8.1 Energy And Life Study Guide Answer Key

1 Cells and Energy Answer Key SECTION 1. CHEMICAL ENERGY AND ATP 1. Molecule; food molecules 2. High-energy; lower-energy 3. Phosphate group 4. A; d; b; c 5. Chemical energy; light energy 9.

Three; two 10. Chemical; molecules SECTION 2.

OVERVIEW OF PHOTOSYNTHESIS 1. Chemical energy 2. Light energy; chemical energy 3. Visible light 4. Photosynthesis 5. Stroma; grana 6.

Equation: 6CO 2 + 6H 2 O C 6 H 12 O 6 + 6O CO 2 and 6H 2 O 9. 6O 2 and C 6 H 12 O b 11.

Require light; energy 12. Do not require light; sugars 13. Refer to Figure 2.2 for a visual answer. The four steps are: d, a, b, c 14. Energy; sugars 15. Independent SECTION 3. PHOTOSYNTHESIS IN DETAIL 1.

Capture; transfer 2. ATP; NADPH 4. B, g, d, f, c, e, a 5. Carbon dioxide 6. 1 b; 2 d; A a; 3 e; 4 c 7.

Synthesizes 9. With no beginning or end. OVERVIEW OF CELLULAR RESPIRATION 1. Energy; oxygen 2. Mitochondria 4. Glucose; ATP 5.

Equation: C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O 8. 6O 2 and C 6 H 12 O CO 2 and 6H 2 O 10. Refer to Figure 4.2 for a visual answer. The four steps are: d, b, a, c 12.

Break down SECTION 5. CELLULAR RESPIRATION IN DETAIL 1. Pyruvate and NADH; ATP 3.

C, b, a, d, e 6. Electrons; hydrogen ions 8. C, d, b, a 9. Electrons SECTION 6.

FERMENTATION 1. Hard exercise 4.

For a visual answer, refer to the lactic acid fermentation diagram in Section 6. The order of the four steps is: d, b, c, a 7. For a visual answer, refer to the alcoholic fermentation diagram in Section 6. The order of the four steps is: c, a, d, b Holt McDougal Biology i Cells and Energy 2 continued 8.

Uses pyruvate and NADH = Both; Recycles NAD + to glycolysis = Both; Produces Lactic Acid = Lactic acid fermentation; Produces alcohol and carbon dioxide = Alcoholic Fermentation. Cheese, yogurt 10.

Carbon dioxide 12. Waste product; muscles Holt McDougal Biology ii Cells and Energy 3 Section 1: Chemical Energy and ATP KEY CONCEPT All cells need chemical energy. VOCABULARY ATP ADP chemosynthesis MAIN IDEA: The chemical energy used for most cell processes is carried by ATP. Circle the word or phrase that best completes the statement.

All cells use adenosine triphosphate (ATP) for energy. ATP is a molecule / organelle that transfers energy from the breakdown of ADP / food molecules to cell processes.

ATP is a high-energy / low-energy molecule that is converted into higher-energy / lower-energy ADP when a phosphate group is removed and energy is released. ADP is converted back into ATP by the addition of a phosphate group / food molecule. Put the letter of the appropriate statement into each box of the cycle diagram below to show the relationship between ATP and ADP. High-energy adenosine triphosphate (ATP) b. Lower-energy adenosine diphosphate (ADP) c.

Energy added from breakdown of carbon-based molecules, phosphate added d. Phosphate removed, energy released Holt McDougal Biology 1 Cells and Energy Section 1: Chemical Energy and ATP 4 continued MAIN IDEA: Organisms break down carbon-based molecules to produce ATP. Put the letter for each of the following six statements into the appropriate list to identify the roles of different types of molecules when they are broken down to make ATP.

Molecules least likely to be broken down b. Molecules most commonly broken down c.

Molecules that store most of the energy in a person s body d. Triglyceride yields about 146 ATP e. Glucose yields about 36 ATP f. Store about the same amount of energy as carbohydrates Type of Molecule Role in ATP Production 5. Carbohydrates 4 calories per mg (4 Calories per gram) 6. Lipids 9 calories per mg (9 Calories per gram) 7. Proteins 9 calories 4 calories per mg (4 Calories per gram) MAIN IDEA: A few types of organisms do not need sunlight and photosynthesis as a source of energy.

Circle the word or phrase that best completes the statement. Chemosynthesis is a process by which some organisms use chemical energy / light energy instead of chemical energy / light energy to make energy-storing carbon-based molecules. Holt McDougal Biology 2 Cells and Energy Section 1: Chemical Energy and ATP 5 continued Vocabulary Check Fill in each blank with the word or phrase that best completes the sentence. The prefix tri- means three, and the prefix di- means two. Therefore, adenosine triphosphate (ATP) has phosphate groups, and adenosine diphosphate (ADP) has phosphate groups. The prefix chemo- means chemical, and synthesis comes from a Greek word that means to put together.

Therefore, chemosynthesis means to put together with chemicals. In chemosynthesis, energy is used to produce carbon-based that store energy. Holt McDougal Biology 3 Cells and Energy Section 1: Chemical Energy and ATP 6 Section 2: Overview of Photosynthesis KEY CONCEPT The overall process of photosynthesis produces sugars that store chemical energy.

VOCABULARY photosynthesis chlorophyll thylakoid light-dependent reactions light-independent reactions MAIN IDEA: Photosynthetic organisms are producers. Circle the word or phrase that best completes the statement.

Some organisms are called producers because they produce the source of chemical energy / light energy for themselves and for other organisms. Photosynthesis captures chemical energy / light energy to make sugars that store chemical energy / light energy. Chlorophyll is a molecule in chloroplasts that absorbs some of the energy in visible light / ultraviolet light. MAIN IDEA: Photosynthesis in plants occurs in chloroplasts. Chloroplasts are membrane-bound organelles where takes place in plants.

Photosynthesis takes place in two parts of a chloroplast: the and the. Thylakoids are coin-shaped, membrane-enclosed compartments inside the.

The overall process of photosynthesis can be written as a chemical equation. Fill in the blanks in the equation below using the appropriate compound from the box. 6O 2 6CO 2 6H 2 O C 6 H 12 O The two reactants in the photosynthesis equation are and. The two products in the photosynthesis equation are and. Holt McDougal Biology 4 Cells and Energy Section 2: Overview of Photosynthesis 7 continued 10. Why is the photosynthesis equation often written with several arrows?

Because many enzymes are added to the reactants to make the products. Because many chemical reactions occur with the help of many enzymes. C Because many reactants can enter into the photosynthesis reaction. Because many products can be made from the photosynthesis reaction. Circle the word or phrase that best completes the statement.

The light-dependent reactions require light / do not require light, and they absorb and transfer sugars / energy. The light-independent reactions require light / do not require light, and they build sugars / energy. Use the space below to sketch a chloroplast. Label the grana, thylakoids, and stroma. Indicate where each of the following steps of the photosynthetic process occurs. Energy carried along the thylakoid membrane is transferred to molecules that carry energy to the light-independent reactions. Carbon dioxide is added to a cycle of chemical reactions to build larger molecules.

A six-carbon simple sugar (usually glucose; C 6 H 12 O 6 ) is formed. Energy from sunlight is absorbed and transferred along the thylakoid membrane. Water molecules are broken down and oxygen is released.

Photosynthesis Holt McDougal Biology 5 Cells and Energy Section 2: Overview of Photosynthesis 8 continued Vocabulary Check Fill in each blank with the word or phrase that best completes the sentence. The prefix photo- means light, and synthesis means to put together. During photosynthesis, from light is used to put together. The prefix chloro- means green, and the suffix -phyll means leaf. Therefore, chlorophyll is the light-absorbing molecule that makes leaves look. The prefix in- means not. Therefore, the reactions in photosynthesis that do not require light are called light.

Holt McDougal Biology 6 Cells and Energy Section 2: Overview of Photosynthesis 9 Section 3: Photosynthesis in Detail KEY CONCEPT Photosynthesis requires a series of chemical reactions. VOCABULARY photosystem electron transport chain ATP synthase Calvin cycle MAIN IDEA: The first stage of photosynthesis captures and transfers energy. The function of the light-dependent reactions is to and energy. Photosystems are groups of that capture and transfer energy. The two molecules that carry energy to the light-independent reactions are and.

Using the diagram on the next page, put each letter from the statements below into a box to show the seven steps of the light-dependent reactions. ATP synthase produces ATP. Chlorophyll (in the thylakoid membrane) absorbs energy from sunlight, and energized electrons enter the electron transport chain. Energized electrons leave the electron transport chain and are used to produce NADPH. Energy from electrons in the transport chain is used to pump hydrogen ions across the thylakoid membrane. Hydrogen ions flow through a channel coupled to ATP synthase. More energy is absorbed and transferred to electrons.

Water molecules are broken down. Oxygen is released as waste and electrons enter chlorophyll. Holt McDougal Biology 7 Cells and Energy Section 3: Photosynthesis in Detail 10 continued MAIN IDEA: The second stage of photosynthesis uses energy from the first stage to make sugars.

The Calvin cycle uses energy from the light-dependent reactions to convert into sugars. Using the diagram on the next page, put the letter from each of the following statements into the appropriate box to show the four steps of the Calvin cycle. A three-carbon molecule exits the cycle. Other three-carbon molecules stay in the cycle. Carbon dioxide is added to the Calvin cycle. Energy is used to convert the remaining three-carbon molecules into fivecarbon molecules. Energy is used to split six-carbon molecules.

Three-carbon molecules are formed and rearranged. When two three-carbon molecules have left the cycle they bond to form a six-carbon sugar (glucose). Holt McDougal Biology 8 Cells and Energy Section 3: Photosynthesis in Detail 11 continued A.

Vocabulary Check Circle the word or phrase that best completes the statement. The electron transport chain is a series of proteins / carbohydrates in the thylakoid membrane along which energized electrons travel. The first part of an enzyme s name tells you about its function.

All enzymes end with the suffix -ase. Therefore, ATP synthase is an enzyme that synthesizes / synchronizes ATP. The word cycle tells you that the chemical reactions of the Calvin cycle go from one to another with a beginning and an end / with no beginning or end. Holt McDougal Biology 9 Cells and Energy Section 3: Photosynthesis in Detail 12 Section 4: Overview of Cellular Respiration KEY CONCEPT The overall process of cellular respiration converts sugar into ATP using oxygen. VOCABULARY cellular respiration aerobic glycolysis anaerobic Krebs cycle MAIN IDEA: Cellular respiration makes ATP by breaking down sugars. Circle the word or phrase that best completes the statement. Cellular respiration is a process that releases glucose / energy from sugars and other carbon-based molecules to make ATP when oxygen / carbon dioxide is present.

Cellular respiration is called an aerobic process, because it needs oxygen / carbon dioxide to take place. Cellular respiration takes place in the chloroplasts / mitochondria. During glycolysis, one molecule of glucose / protein is split into two threecarbon molecules and two ADP / ATP are formed. MAIN IDEA: Cellular respiration makes ATP by breaking down sugars. Circle the two ways in which cellular respiration seems to be the opposite of photosynthesis. The reactions occur at either end of the chloroplast. The overall chemical equations are the reverse of each other.

Cellular respiration breaks down sugars to make ATP, and photosynthesis uses ATP to make sugars. Cellular respiration produces oxygen, and photosynthesis produces carbon dioxide. Circle the two parts of a mitochondrion where cellular respiration takes place. Matrix b stroma c. Inner mitochondrial membrane d. Outer mitochondrial membrane Holt McDougal Biology 10 Cells and Energy Section 4: Overview of Cellular Respiration 13 continued 7.

The overall process of cellular respiration can be written as a chemical equation. Fill in the blanks in the equation below using the appropriate compound from the box. 6O 2 6CO 2 6H 2 O C 6 H 12 O The two reactants in the cellular respiration equation are and. The two products in the cellular respiration equation are and.

Why is the cellular respiration equation written with several arrows? Because a series of products result from the reaction. Because a series of reactants enter into the reaction. Because a series of chemicals is added to the process. Because a series of chemical reactions occurs. Use the space below to sketch a mitochondrion. Label the matrix and inner membrane.

8.1 Energy And Life Study Guide Answer Key

Indicate where each of the following steps of the cellular respiration process occurs. Energized electrons are passed along the electron transport chain in the inner mitochondrial membrane. Energy is transferred to the second stage of cellular respiration (the electron transport chain). A large number of ATP are formed. Oxygen picks up electrons, and water is released as a waste product.

Three-carbon molecules enter the Krebs cycle and are broken down. ATP and other energy-carrying molecules are formed. Carbon dioxide is released as a waste product.

Cellular Respiration Holt McDougal Biology 11 Cells and Energy Section 4: Overview of Cellular Respiration 14 continued Vocabulary Check Fill in the blank with the word or phrase that best completes the sentence. The prefix glyco- comes from a Greek word that means sweet. The suffix -lysis comes from a Greek word that means to loosen.

Therefore, during glycolysis, a is broken down (or loosened ). Glycolysis is an anaerobic process, because it takes place without.

During the Krebs cycle, chemical reactions carbonbased molecules. Holt McDougal Biology 12 Cells and Energy Section 4: Overview of Cellular Respiration 15 Section 5: Cellular Respiration in Detail KEY CONCEPT Cellular respiration is an aerobic process with two main stages. MAIN IDEA: Glycolysis is needed for cellular respiration. The function of glycolysis is to split and produce energycarrying molecules. Three molecules are formed during glycolysis when oxygen is available. And are used in cellular respiration.

Can be used for cell processes. Glycolysis results in a net gain of two ATP molecules. This means that ATP are used to split glucose and ATP are produced. Therefore, in the end, there are two additional ATP. MAIN IDEA: The Krebs cycle is the first main part of cellular respiration.

What is the function of the Krebs cycle? To produce carbon-based molecules by cellular respiration. To produce carbon-based molecules by glycolysis. To produce energy-carriers from the breakdown of carbon-based molecules.

To produce energy-carriers from the synthesis of carbon-based molecules. Put the letter from each of the following statements into the appropriate box of the cycle diagram below to summarize the six steps of the Krebs cycle. Citric acid broken down, carbon dioxide released, NADH produced. Citric acid formed. Coenzyme A binds to two-carbon molecule; enters Krebs cycle. Five-carbon molecule broken down, carbon dioxide released, NADH and ATP produced.

Four-carbon molecule rearranged, NADH and FADH 2 produced. Holt McDougal Biology 13 Cells and Energy Section 5: Cellular Respiration in Detail 16 continued Pyruvate broken down MAIN IDEA: The electron transport chain is the second main part of cellular respiration.

Circle the word or phrase that best completes the statement. The electron transport chain in cellular respiration is located on the inner / outer mitochondrial membrane. The electron transport chain uses energy from electrons / protons to pump oxygen ions / hydrogen ions across the membrane, so that the ions can flow back through ATP synthase to produce ATP. Holt McDougal Biology 14 Cells and Energy Section 5: Cellular Respiration in Detail 17 continued 8. Use the statements below to fill in the sequence showing the four steps of the electron transport chain. Oxygen picks up electrons from the transport chain and hydrogen ions; water is produced and released. Hydrogen ions flow through ATP synthase; ATP is produced.

High-energy electrons removed from NADH and FADH 2 by proteins in the transport chain. Energy from the electrons used to pump hydrogen ions across the inner mitochondrial membrane. Cellular respiration can only operate when oxygen is available to pick up at the end of the electron transport chain.

Holt McDougal Biology 15 Cells and Energy Section 5: Cellular Respiration in Detail 18 Section 6: Fermentation KEY CONCEPT Fermentation allows the production of a small amount of ATP without oxygen. VOCABULARY fermentation lactic acid MAIN IDEA: Fermentation allows glycolysis to continue. Fermentation is important, because it allows glycolysis to continue making when oxygen is unavailable for cellular respiration. Fermentation removes from NADH and recycles NAD + to glycolysis.

Fermentation takes place in your muscle cells during, when not enough oxygen is available. Fermentation is an anaerobic process, because it occurs without. Fermentation is involved in the production of ATP by allowing glycolysis to take place. Glycolysis yields net ATP. In the space below, draw the process of lactic acid fermentation and label it with the statements listed. NAD + is recycled to glycolysis. NADH is used to convert pyruvate into lactic acid.

NADH is changed into NAD +. Pyruvate and glycolysis enter fermentation. Lactic Acid Fermentation Holt McDougal Biology 16 Cells and Energy Section 6: Fermentation 19 continued MAIN IDEA: Fermentation and its products are important in several ways. In the space below, draw the process of alcoholic fermentation and label it with the statements listed. NADH is used to convert pyruvate into alcohol and carbon dioxide.

NAD + is recycled to glycolysis. Pyruvate and glycolysis enter fermentation. NADH is changed into NAD +. Alcoholic Fermentation 8. Place a check mark in the appropriate boxes below to show how lactic acid fermentation and alcoholic fermentation are similar and how they are different.

Uses pyruvate and NADH Recycles NAD + to glycolysis Produces lactic acid Produces alcohol and carbon dioxide Lactic Acid Fermentation Alcoholic Fermentation Both Holt McDougal Biology 17 Cells and Energy Section 6: Fermentation 20 continued 9. Name one commercial use of lactic acid fermentation. Name one commercial use of alcoholic fermentation. Vocabulary Check Circle the word or phrase that best completes the statement. The term fermentation is based on a word that means to bubble. This meaning is related to the fermentation process, because bubbles of carbon dioxide / oxygen are produced during alcoholic fermentation.

Lactic acid is the three-carbon reactant / waste product of lactic acid fermentation. It causes a burning feeling in your muscles / blood vessels during exercise Holt McDougal Biology 18 Cells and Energy Section 6: Fermentation.

Energy and Life Organisms use sugar as a source of energy to do work. All living things require energy to do the work necessary for survival and reproduction. This is true for bacteria, plants, and animals. But what is energy?

Energy is simply the ability to do work, where work is done when a force moves an object. Let's consider your own needs for a moment. You need energy to turn on and turn off your computer.

You need energy to get out of bed in the morning. You even need energy to listen to this lesson and think about what it says. And, yes, you need energy to reproduce. So where does energy come from and how do we use it? On Earth, energy ultimately comes from the sun. Plants use the sun's energy to make sugar.

Organisms, in turn, use sugar as a source of energy to do work. In this lesson, we will explore how living organisms utilize energy. We will first consider how plants use energy from the sun to make sugar. Then we will explore how organisms use energy from the sugar to do work.

How Plants Transform Energy from the Sun Plants use energy from sunlight to make sugar and oxygen from carbon dioxide and water. The process by which carbon dioxide and water are converted to sugar and oxygen using sunlight is referred to as. This is an, meaning energy is required by the reaction. Specifically, energy is required to put the carbon dioxide and the water molecules together to form sugar.

Sun provides the energy needed to drive photosynthesis, and some of the energy used to make the sugar is stored in the sugar molecule. The sun provides the energy needed to drive photosynthesis. How Organisms Use Energy from Sugar Now that we know how plants synthesize sugar, let's explore how organisms use the sugar as a source of energy. In short, organisms break down the sugar to release its stored energy. The energy released from the breakdown of sugar is used by the cells to make another chemical that we call adenosine triphosphate, or simply abbreviated ATP.

The synthesis of ATP by cells is referred to as cellular respiration. This is an as energy is released as a result of the reaction. Energy is released when the sugar is broken down into smaller parts: carbon dioxide and water. As you can see on the screen, sugar and oxygen are the reactants, and carbon dioxide and water are the products of cellular respiration.

Does that reaction look familiar? Well it should, because cellular respiration is simply the reverse of photosynthesis. Photosynthesis and cellular respiration are related as the products of one become the reactants for the other. In fact, cellular respiration and photosynthesis are dependent on one another. Why does the cell have to convert energy stored in sugar into energy stored in ATP? Why can't the cell just use sugar in the first place, as a source of energy, to do the work it needs to do?

In other words, why is cellular respiration necessary for life? To answer that question, let's think of energy as being analogous to money. We all like money. While the Japanese yen is indeed real money, you can't use it to buy goods in an American store.

Therefore, you have to first exchange the yen for dollars and then you can buy stuff in an American store. Likewise, sugar is a good source of energy. Sugar is a good source of energy but cells can't directly use it to do work. Therefore, the sugar must first be converted into a more usable form, and that usable form is ATP. Let's look at an example: our muscle cells need and use ATP to do the work of contraction. The muscles break down the sugar to get the energy they need to make ATP. Cellular respiration is the reverse of photosynthesis.

Lesson Summary In summary, all living organisms require energy for both survival and reproduction. Energy is the ability to do work, where work is done when a force moves an object.

While the sun provides energy for our entire planet, the sun's energy must be transformed into more usable forms for living organisms. Plants utilize photosynthesis for the production of sugar and oxygen from carbon dioxide and water. Photosynthesis is endergonic as energy is required by the reaction.

The sun provides the energy for photosynthesis. Cells, in turn, utilize sugar as a source of energy. Cellular respiration is the synthesis of ATP using energy released by the breakdown of sugar to carbon dioxide and water. As energy is released by the reaction, the breakdown of sugar is exergonic. The products of cellular respiration are carbon dioxide and water.

These products are used by plants to make sugar and oxygen through photosynthesis. The energy released from the breakdown of sugar is used by cells to make ATP, which is the most usable form of energy by cells. Cells then break down the ATP to provide energy necessary to perform work - for example, contraction of our muscles. Learning Outcomes Completing this lesson should enable you to:. Define energy and work.

Differentiate between an endergonic and exergonic reaction. Summarize photosynthesis and cellular respiration as well as identify the products of each. Understand why photosynthesis and cellular respiration are dependent on each other.