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Chapter 8

Chapter 8. Cellular Energy. Section 1. How Organisms Obtain Energy. Section 1: How Organisms Obtain Energy. All living organisms use energy to carry out all biological processes. Transformation of Energy Cellular processes require ____________ – the ability to do work.

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Chapter 8

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  1. Chapter 8 Cellular Energy

  2. Section 1 How Organisms Obtain Energy

  3. Section 1: How Organisms Obtain Energy All living organisms use energy to carry out all biological processes.

  4. Transformation of Energy • Cellular processes require ____________– the ability to do work. • _______________is the study of the flow and transformation of energy in the universe. How Organisms Obtain Energy

  5. Transformation of Energy Laws of thermodynamics • First law—the law of conservation of energy: energy can be converted from one form to another, but it cannot be created nor ______________. • Second law: energy cannot be converted without the loss of usable energy, that is, _________________—disorder or unusable energy--increases. How Organisms Obtain Energy

  6. Transformation of Energy Autotrophs and Heterotrophs • Directly or indirectly, nearly all the energy for life comes from the Sun. • _____________make their own food, either with energy from the sun or from inorganic substances. • ________________ingest other organisms to obtain energy. How Organisms Obtain Energy

  7. Metabolism • All of the chemical reactions in a cell are referred to as the cell’s _________. • A series of chemical reactions in which the product of one is the substrate for the next is called a metabolic pathway. • _________pathways release energy by breaking down larger molecules. • _____________pathways use energy to build larger molecules. How Organisms Obtain Energy

  8. Metabolism • ________________– anabolic pathway in which light energy from the Sun is converted to chemical energy for use by the cell • ___________________– catabolic pathway in which organic molecules are broken down to release energy for use by the cell How Organisms Obtain Energy

  9. ATP: The Unit of Cellular Energy • In living things, chemical energy is stored in biological molecules. • ___________________(ATP) is the most important biological molecule that provides chemical energy. How Organisms Obtain Energy

  10. ATP: The Unit of Cellular Energy ATP structure • Most abundant ____________-carrier in cells • __________made of an adenine base, a ribose sugar, and three phosphate groups How Organisms Obtain Energy

  11. ATP: The Unit of Cellular Energy ATP function • Releases energy when the bond between the second and third phosphate groups is broken. • Transforms into a molecule called adenosine diphosphate (_____) and a free phosphate group. How Organisms Obtain Energy

  12. ATP • When chlorophyll absorbs light, it is absorbing energy • It stores it in the __________ of Adenosine Triphosphate (ATP)

  13. ATP, continued. • Carbs are most commonly broken down to make ATP. • Breakdown of glucose yields ____ ATP. • ATP = Energy currency of the cell. • Cells use ATP for functions such as building molecules & moving materials by ______________. • ATP releases energy when phosphate group released. • Becomes Adenosine DiPhosphate(_____). • Can be converted back to ATP by adding phosphate.

  14. ATP vs. ADP

  15. ATP ADP Cycle

  16. Essential Questions • What are the two laws of thermodynamics? • What is the difference between an anabolic pathway and a catabolic pathway? • How does ATP work in a cell? How Organisms Obtain Energy

  17. Section 2 Photosynthesis

  18. Section 2: Photosynthesis Light energy is trapped and converted into chemical energy during photosynthesis.

  19. Overview of Photosynthesis • Most autotrophs make organic compounds using __________________. • Photosynthesis is the process of converting ________energy into chemical energy. Photosynthesis

  20. THE FORMULA, continued.

  21. Overview of Photosynthesis • Photosynthesis occurs in ______phases. • In the _____________ phase, light energy is converted into chemical energy. • In the ______________ phase, chemical energy used to synthesize glucose. Photosynthesis

  22. Phase One: Light Reactions • The absorption of ____________is the first step in photosynthesis. • Once light energy is captured, it can be stored as _______or NAPDH. Photosynthesis

  23. Phase One: Light Reactions Chloroplasts • Are organelles that capture light energy • Contain two main compartments: • ________________: flattened saclike membranes • Stacks of thylakoids are called grana. • The fluid filled space outside the grana called the __________________ Photosynthesis

  24. Chloroplast structure

  25. Phase One: Light Reactions Pigments • Light-absorbing colored molecules called ________are found in the thylakoid membranes. • Different pigments absorb specific wavelengths of light. • Most common pigment in plants is _________________. • Plants also have accessory pigments. Photosynthesis

  26. Phase One: Light Reactions Electron transport • The thylakoid membrane has a large surface area, providing space for a large number of electron transporting molecules and two types of protein complexes called _____________________. • Photosystems house the light-capturing pigments. Photosynthesis

  27. Phase One: Light Reactions Electron transport • Light energy excites electrons in _______________________. • This light energy causes a water molecule to split – releasing an electron into the electron transport system, a hydrogen ion (H+ or proton) into the thylakoid space, and oxygen as a waste product. Photosynthesis

  28. Phase One: Light Reactions Electron transport • The activated electrons move from photosystem II to an acceptor molecule in the __________________membrane. • The electron acceptor molecule transfers the electrons along a series of electron carriers to photosystem I. Photosynthesis

  29. Phase One: Light Reactions Electron transport • In the presence of light, photosystem I transfers the electrons to a protein. • The protein transfers the electrons to the carrier molecule _________forming the energy storage molecule NADPH. Photosynthesis

  30. Phase One: Light Reactions Electron transport • ATP is produced in conjunction with the electron transport system through chemiosmosis • ATP is produced through the flow of electrons _____a concentration gradient • The breakdown of water provides the necessary protons for _____synthesis Photosynthesis

  31. Phase Two: The Calvin Cycle (light independent reactions) • In the second phase of photosynthesis, called the ___________, energy is stored in organic molecules such as ____________. Photosynthesis

  32. Phase Two: The Calvin Cycle • The first step of the Calvin cycle is called ____________ fixation. • CO2 molecules combine with 5-carbon molecules to form 3-phosphoglycerate (3-PGA) Photosynthesis

  33. Phase Two: The Calvin Cycle • In the second step, chemical energy stored in ATP and NADPH is transferred to the 3-PGA to form glyceraldehyde 3-phospate (_________). Photosynthesis

  34. Phase Two: The Calvin Cycle • In the third step, some G3P molecules leave the cycle to be used for the production of _________________and other organic compounds. Photosynthesis

  35. Phase Two: The Calvin Cycle • In the fourth and final step, an enzyme called ______converts the remaining G3P molecules into 5-carbon molecules called ________1,5-bisphospates (RuBP). • These molecules combine with new CO2 and continue the cycle. Photosynthesis

  36. 2 Main steps of PS - Summary • Light reactions—occurs only in the presence of ___________ • Occurs in the grana (thylakoids) of the chloroplasts • Also known as Photolysisbecause light is used to __________ _________ molecules into hydrogen and oxygen

  37. 2 Main steps of PS - Summary 2. Dark Reactions—can occur in light ____ darkness. Follows light reactions • Occurs in the stroma of the chloroplasts • Also known as Carbon fixationbecause CO2 will get “fixed up” with the hydrogens and energy from the light reaction

  38. Light Reactions Take place within the membrane of the thylakoid. • Chlorophyll absorbs energy from sunlight. • Water is __________ _________ • Oxygen is ______________ • Oxygen leaves the plant and goes into the air

  39. The Dark Reactions Occur in stroma of chloroplasts. • _________ is added to a cycle of reactions to build larger molecules • A molecule of simple sugar is formed • _____________

  40. Alternative Pathways C4 plants • The C4 pathway allows plants to maintain photosynthesis while reducing _________ loss. • Significant structural modification in the arrangement of cells within the leaves – separate CO2 uptake from location of Calvin cycle Photosynthesis

  41. Alternative Pathways CAM plants • Crassulacean acid metabolism (________) is found in desert plants. • Collect CO2 at night and store it in organic compounds • During the day, release CO2 from organic compounds for the light-dependent cycle of photosynthesis Photosynthesis

  42. Essential Questions • What are the two phases of photosynthesis? • What is the function of a chloroplast during the light reactions? • How can electron transport be described and diagramed? Photosynthesis

  43. Section 3 Cellular Respiration

  44. Section 3: Cellular Respiration Living organisms obtain energy by breaking down organic molecules during cellular respiration.

  45. Overview of Cellular Respiration • Organisms obtain energy in a process called _________________. • Respiration harvests electrons from organic molecules and uses the energy to make _____________. • The equation for cellular respiration is the opposite of the equation for ___________________: Cellular Respiration

  46. Overview of Cellular Respiration • Cellular respiration occurs in two main parts: glycolysis and aerobic respiration. • Glycolysis is an ________ process, meaning it does not require ______. • Aerobic respiration involves the ______cycle and electron transport. • Aerobic processes require oxygen. Cellular Respiration

  47. Glycolysis • Glucose is broken down in the cytoplasm through the process of _______________. • ____molecules of ATP and ____ molecules of NADH are formed for each molecule of glucose that is broken down. Cellular Respiration

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