Chapter 8 Cellular Energy Section 1 How Organisms

Chapter 8 Cellular Energy Section 1: How Organisms Obtain Energy Section 2: Photosynthesis Section 3: Cellular Respiration Click on a lesson name to select.

Chapter 8 Cellular Energy 8. 1 How Organisms Obtain Energy Transformation of Energy § Energy is the ability to do work. § Thermodynamics is the study of the flow and transformation of energy in the universe.

Chapter 8 Cellular Energy 8. 1 How Organisms Obtain Energy Laws of Thermodynamics § First law—energy can be converted from one form to another, but it cannot be created nor destroyed. § Second law—energy cannot be converted without the loss of usable energy.

Chapter 8 Cellular Energy 8. 1 How Organisms Obtain Energy Autotrophs and Heterotrophs § Autotrophs are organisms that make their own food. § Heterotrophs are organisms that need to ingest food to obtain energy.

Chapter 8 Cellular Energy 8. 1 How Organisms Obtain Energy Metabolism § All of the chemical reactions in a cell § Photosynthesis—light energy from the Sun is converted to chemical energy for use by the cell § Cellular respiration—organic molecules are broken down to release energy for use by the cell

Chapter 8 Cellular Energy 8. 1 How Organisms Obtain Energy ATP: The Unit of Cellular Energy § ATP releases energy when the bond between the second and third phosphate groups is broken, forming a molecule called adenosine diphosphate (ADP) and a free phosphate group. ATP

Chapter 8 Cellular Energy 8. 2 Photosynthesis Overview of Photosynthesis § Photosynthesis occurs in two phases. § Light-dependent reactions § Light-independent reactions

Chapter 8 Cellular Energy 8. 2 Photosynthesis Phase One: Light Reactions § The absorption of light is the first step in photosynthesis. § Chloroplasts capture light energy.

Chapter 8 Cellular Energy 8. 2 Photosynthesis Electron Transport § Light energy excites electrons in photosystem II and also causes a water molecule to split, releasing an electron into the electron transport system, H+ into the thylakoid space, and O 2 as a waste product.

Chapter 8 Cellular Energy 8. 2 Photosynthesis § The excited electrons move from photosystem II to an electron-acceptor molecule in the thylakoid membrane. § The electron-acceptor molecule transfers the electrons along a series of electron-carriers to photosystem I.

Chapter 8 Cellular Energy 8. 2 Photosynthesis § Photosystem I transfers the electrons to a protein called ferrodoxin. § Ferrodoxin transfers the electrons to the electron carrier NADP+, forming the energystoring molecule NADPH.

Chapter 8 Cellular Energy

Chapter 8 Cellular Energy 8. 2 Photosynthesis Phase Two: The Calvin Cycle § In the second phase of photosynthesis, called the Calvin cycle, energy is stored in organic molecules such as glucose.

Chapter 8 Cellular Energy

Chapter 8 Cellular Energy 8. 2 Photosynthesis § Six CO 2 molecules combine with six 5 -carbon compounds to form twelve 3 -carbon molecules called 3 -PGA. § The chemical energy stored in ATP and NADPH is transferred to the 3 -PGA molecules to form high-energy molecules called G 3 P.

Chapter 8 Cellular Energy 8. 2 Photosynthesis § Two G 3 P molecules leave the cycle to be used for the production of glucose and other organic compounds. § An enzyme called rubisco converts the remaining ten G 3 P molecules into 5 -carbon molecules called Ru. BP. § These molecules combine with new carbon dioxide molecules to continue the cycle.

Chapter 8 Cellular Energy 8. 2 Photosynthesis Alternative Pathways § C 4 plants § CAM plants

Chapter 8 Cellular Energy 8. 3 Cellular Respiration Overview of Cellular Respiration § Organisms obtain energy in a process called cellular respiration. § The equation for cellular respiration is the opposite of the equation for photosynthesis.

Chapter 8 Cellular Energy 8. 3 Cellular Respiration § Cellular respiration occurs in two main parts. § Glycolysis § Aerobic respiration

Chapter 8 Cellular Energy 8. 3 Cellular Respiration Glycolysis § Glucose is broken down in the cytoplasm through the process of glycolysis. § Two molecules of ATP and two molecules of NADH are formed for each molecule of glucose that is broken down.

Chapter 8 Cellular Energy 8. 3 Cellular Respiration Krebs Cycle § Glycolysis has a net result of two ATP and two pyruvate. § Most of the energy from the glucose is still contained in the pyruvate. § The series of reactions in which pyruvate is broken down into carbon dioxide is called the Krebs cycle.

Chapter 8 Cellular Energy 8. 3 Cellular Respiration § The net yield from the Krebs cycle is six CO 2 molecules, two ATP, eight NADH, and two FADH 2.

Chapter 8 Cellular Energy

Chapter 8 Cellular Energy 8. 3 Cellular Respiration Electron Transport § Final step in the breakdown of glucose § Point at which ATP is produced § Produces 24 ATP

Chapter 8 Cellular Energy 8. 3 Cellular Respiration Anaerobic Respiration § The anaerobic pathway that follows glycolysis § Two main types § Lactic acid fermentation § Alcohol fermentation Cellular Respiration

Chapter 8 Cellular Energy Chapter Resource Menu Chapter Diagnostic Questions Formative Test Questions Chapter Assessment Questions Standardized Test Practice biologygmh. com Glencoe Biology Transparencies Image Bank Vocabulary Animation Click on a hyperlink to view the corresponding feature.

Chapter 8 Cellular Energy Chapter Diagnostic Questions Which statement describes the law of conservation of energy? A. Energy cannot be converted or destroyed. B. Energy can be converted and destroyed. C. Energy can be converted but not destroyed. D. Energy can be destroyed but not converted. 1. 2. 3. 4. A B C D

Chapter 8 Cellular Energy Chapter Diagnostic Questions In which metabolic process are molecules broken down to produce carbon dioxide and water? A. photosynthesis B. cellular respiration C. homeostasis D. fermentation 1. 2. 3. 4. A B C D

Chapter 8 Cellular Energy Chapter Diagnostic Questions At the end of the Calvin cycle, where is energy stored? A. NADPH B. ATP C. chloroplast D. glucose 1. 2. 3. 4. A B C D

Chapter 8 Cellular Energy 8. 1 Formative Questions Which law of thermodynamics explains why the ladybug receives the least amount of usable energy? A. the first law of thermodynamics B. the second law of thermodynamics 1. 2. A B

Chapter 8 Cellular Energy 8. 1 Formative Questions All of the energy from the food you eat comes from the sun. A. true B. false 1. 2. A B

Chapter 8 Cellular Energy 8. 1 Formative Questions Why is cellular respiration a catabolic pathway? A. Energy is used to form glucose and oxygen. B. Energy is converted from water to carbon dioxide. C. Energy that is lost is converted to thermal energy. D. Energy is released by the breakdown of molecules. 1. 2. 3. 4. A B C D

Chapter 8 Cellular Energy 8. 1 Formative Questions Why is adenosine triphosphate (ATP) such an important biological molecule? A. It captures light energy from the sun. B. It is produced in anabolic pathways. C. It stores and releases chemical energy. D. It converts mechanical energy to thermal energy. 1. 2. 3. 4. A B C D

Chapter 8 Cellular Energy 8. 2 Formative Questions Where in the plant cell does photosynthesis take place? A. chloroplasts B. Golgi apparatus C. mitochondria D. vacuoles 1. 2. 3. 4. A B C D

Chapter 8 Cellular Energy 8. 2 Formative Questions Which range of wavelengths is reflected by chlorophylls a and b? A. 400 -500 nm B. 500 -600 nm C. 600 -700 nm 1. 2. 3. A B C

Chapter 8 Cellular Energy 8. 2 Formative Questions Which mechanism of photosynthesis uses the movement of hydrogen ions (H+) across a concentration gradient to synthesize ATP? A. absorption B. chemiosmosis C. electron transport D. C 2 pathway 1. 2. 3. 4. A B C D

Chapter 8 Cellular Energy 8. 2 Formative Questions How are the C 4 pathway and the CAM pathway an adaptive strategy for some plants? A. They accelerate photosynthesis. B. They release more oxygen. C. They help the plant conserve water. D. They reduce the requirement for ATP. 1. 2. 3. 4. A B C D

Chapter 8 Cellular Energy 8. 3 Formative Questions What is the overall purpose of cellular respiration? A. to make ATP B. to process H 2 O C. to store glucose D. to deliver oxygen 1. 2. 3. 4. A B C D

Chapter 8 Cellular Energy 8. 3 Formative Questions Which represents the general sequence of cellular respiration? A. TCA cycle chemiosmosis glycolysis B. glycolysis Krebs cycle electron transport C. electron absorption catalysis phosphorylation D. aerobic pathway anaerobic pathway fermentation 1. 2. 3. 4. A B C D

Chapter 8 Cellular Energy 8. 3 Formative Questions Which stage of cellular respiration is the anaerobic process? A. glycolysis B. Krebs cycle C. electron transport 1. 2. 3. A B C

Chapter 8 Cellular Energy 8. 3 Formative Questions Which molecule generated by the Krebs cycle is a waste product? A. Co. A B. CO 2 C. FADH 2 D. NADH 1. 2. 3. 4. A B C D

Chapter 8 Cellular Energy Chapter Assessment Questions Look at the following figure. Which part of the chloroplast is a sac-like membrane arranged in stacks? A. grana B. stroma C. thylakoids D. Golgi apparatus 1. 2. 3. 4. A B C D

Chapter 8 Cellular Energy Chapter Assessment Questions During the Krebs cycle, pyruvate is broken down into what compound? A. H 2 O B. O 2 C. CO D. CO 2 1. 2. 3. 4. A B C D

Chapter 8 Cellular Energy Chapter Assessment Questions Look at the following figure. Which molecule is released when ATP becomes ADP? A. phosphate group B. water molecule C. ribose sugar D. energy cells 1. 2. 3. 4. A B C D

Chapter 8 Cellular Energy Standardized Test Practice Which metabolic process is photosynthesis? A 1. 2. B A B

Chapter 8 Cellular Energy Standardized Test Practice At the beginning of photosynthesis, which molecule is split to produce oxygen (O 2) as a waste product? A. CO 2 B. H 2 O C. C 6 H 12 O 6 D. 3 -PGA 1. 2. 3. 4. A B C D

Chapter 8 Cellular Energy Standardized Test Practice Which molecule helps provide the energy that drives this cycle? A. 3 -PGA B. CO 2 C. NADPH D. rubisco 1. 2. 3. 4. A B C D

Chapter 8 Cellular Energy Standardized Test Practice Which product of the Calvin cycle is used for the production of glucose and other organic compounds? A. ADP B. CO 2 C. G 3 P D. NADP+ 1. 2. 3. 4. A B C D

Chapter 8 Cellular Energy Standardized Test Practice What is the final step of cellular respiration? A. O 2 and H+ form H 2 O. B. Electrons and H 2 O generate ATP. C. C 6 H 12 O 6 is broken down into CO 2. D. NADH and FADH 2 gain electrons. 1. 2. 3. 4. A B C D

Chapter 8 Cellular Energy Standardized Test Practice What prevents pyruvate from entering the Krebs cycle and instead results in this pathway? A. a buildup of CO 2 B. a lack of oxygen C. an excess of glucose D. an increased demand for ATP 1. 2. 3. 4. A B C D

Chapter 8 Cellular Energy Standardized Test Practice Which is not a process that occurs in both cellular respiration and glycolysis? A. chemiosmosis B. electron transport C. glycolysis D. production of G 3 P 1. 2. 3. 4. A B C D

Chapter 8 Cellular Energy Glencoe Biology Transparencies

Chapter 8 Cellular Energy Image Bank

Chapter 8 Cellular Energy Vocabulary Section 1 energy thermodynamics metabolism Photosynthesis cellular respiration adenosine triphosphate (ATP)

Chapter 8 Cellular Energy Vocabulary Section 2 thylakoid granum stroma pigment NADP+ Calvin cycle rubisco

Chapter 8 Cellular Energy Vocabulary Section 3 anaerobic process aerobic respiration aerobic process glycolysis Krebs cycle fermentation

Chapter 8 Cellular Energy Animation § ATP § The Calvin Cycle § Visualizing Electron Transport § The Krebs Cycle (Citric Acid Cycle)

Chapter 8 Cellular Energy

Chapter 8 Cellular Energy

Chapter 8 Cellular Energy