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Cell Energy

Cell Energy . Chapter 4. 4.1 Chemical Energy and ATP. The chemical energy that all cells use is in the form of ATP (adenosine triphosphate ) This energy comes from the breakdown of food molecules. ATP. ATP has 3 phosphate groups Energy is stored between the bonds of the phosphate groups

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Cell Energy

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  1. Cell Energy Chapter 4

  2. 4.1 Chemical Energy and ATP • The chemical energy that all cells use is in the form of ATP (adenosine triphosphate) • This energy comes from the breakdown of food molecules

  3. ATP • ATP has 3 phosphate groups • Energy is stored between the bonds of the phosphate groups • When the 3rd phosphate is removed, energy is released, then the molecule becomes ADP (adenosine diphosphate)

  4. ATP vs. ADP

  5. What is the role of ATP in living things? • ANSWER: • ATP is the chemical energy that all cells can use

  6. Food must be digested into smaller molecules such as carbohydrates, lipids, and proteins in order for you cells to make ATP • A simple sugar molecule produces about 36 ATP molecules • A fat molecule produces about 146 ATP molecules • A protein molecule produces about 36 ATP molecules • Proteins are not used for energy

  7. In the section above, circle the names of 3 carbon-based molecules that your cells can use to make ATP • Simple sugar = carbohydrate • Fat = lipid • Protein

  8. Some organisms produce their own energy from sunlight. • Some organisms consume plants and/or animals to obtain energy. • Other organisms can obtain energy from chemicals through chemosynthesis. All organisms need ATP for energy no matter how they obtain it.

  9. What is the source of energy for organisms that use chemosynthesis? • ANSWER: • Chemicals such as sulfides

  10. 4.1 Vocabulary Check • 1. high-energy molecule with 3 phosphates: • ATP • 2. lower-energy molecule with 2 phosphates: • ADP • 3. use of chemicals as an energy source: • Chemosynthesis

  11. 4.1 Vocabulary Check • 5. The word beginning chemo- means “chemical.” Synthesis means “making something through chemical reactions.” How does the meaning of the word parts relate to the meaning of the term chemosynthesis? • Making energy through chemical reactions

  12. 4.2 Overview of Photosynthesis • Plants capture energy from sunlight, and store it as chemical energy in the form of sugars. • These sugars are made through photosynthesis • Photosynthesis takes place in a plant cells’s chloroplasts

  13. Chlorophyll absorbs the light energy from the sun • *Visible light looks white but is made up of different wavelengths (colors) of light • The two types of chlorophyll absorb red and blue wavelengths and reflect green light

  14. Two main parts of chloroplasts are needed for photosynthesis: • Chlorophyll is located in membranes of thylakoids (shaped like coins) • Thylakoids are stacked = grana • Stroma is fluid that surrounds the grana

  15. Stages of Photosynthesis • Stage 1: Light Dependent Reactions • Light is absorbed by chlorophyll in thylakoid membrane • Light energy breaks water into oxygen molecules and release energy for Stage 2 • Stage 2: Light Independent Reactions • Energy from Stage 1 is used to power chemical reactions which convert carbon dioxide into glucose

  16. Photosynthesis Equation

  17. 4.2 Vocabulary Check • 1. Which two terms are things that are found in the chloroplasts? • Chlorophyll and Thylakoid • 2. Which term is a process that is made up of two other terms? • Photosynthesis • Which term is the part of photosynthesis when light energy is captured and transferred to a molecules such as ATP? • Light-dependent reactions

  18. 4. Which term is the part of photosynthesis when energy is used to make sugars like glucose? • Light-independent reactions • 5. Where in the plant cell does photosynthesis take place? • Chloroplast • 6. What molecule absorbs sunlight for photosynthesis? • Chlorophyll

  19. 7. Why are plants called producers? • They produce their own energy from the sun • 8. Complete the chart below:

  20. Section 4.3: Photosynthesis in Detail Light Dependent Reactions • STAGE 1 • take place within and across the thylakoids • called the light dependent reaction • reactants: water, sunlight • products: oxygen • Chlorophyll captures energy from sunlight. The energy is transferred along the thylakoid membrane. Water molecules are broken down and oxygen is released (waste). • STAGE 2 • second part of light dependent reaction • The light energy is converted to chemical energy, which is temporarily stored in ATP.

  21. Summary of Light-dependent reactions • Energy is captured from sunlight by light-absorbing molecules. The energy is transferred to electrons that enter an electron transport chain. • Water molecules are broken down into H+ ions and electrons that are used in the light-dependent reactions. • Energized electrons have two functions: provide energy for H+ ion transport and add NADP+ to form NADPH • The flow of H+ ions through ATP synthase makes ATP • The products are oxygen, NADPH, and ATP

  22. Light Independent Reaction • STAGE 3 • occurs in stroma • called the Calvin cycle or light independent reaction • reactants: Carbon dioxide (CO2) • The chemical energy made and stored in ATP from the light dependent reaction powers the formation of organic compounds (glucose), using CO2.

  23. Summary of the Light-Independent Reactions • Carbon dioxide enters the Calvin Cycle • ATP and NADPH from the light-dependent reactions transfer energy to the Calvin cycle and keep the cycle going • One high-energy three-carbon molecule is made for every three molecules of carbon dioxide that enter the cycle. • Two high-energy three-carbon molecules are bonded together to make a sugar. Therefore, six molecules of carbon dioxide must by added to the Calvin cycle to make one six-carbon sugar • The products are a six-carbon sugar such as glucose, NADP+ and ADP. The NADP+ and ADP molecules return to the light-dependent reactions.

  24. Section 4.4 Overview of Cellular Respiration • Using oxygen to produce ATP by breaking down carbon-based molecules, cellular respiration • Because oxygen is needed, cellular respiration is an aerobic process. • Takes place in the mitochondria.

  25. Before Cellular Respiration… • Food must be broken down into smaller molecules such as glucose • Glucose as 6 carbon molecules • Glycolysis further breaks down glucose into 2 three-carbon molecules (pyruvic acid) • Happens in the cytoplasm of the cell • Glycolysis is an anaerobic process

  26. Why is cellular respiration called an aerobic process? • ANSWER: • Oxygen is needed

  27. Stages of Cell Respiration • Stage 1: Krebs Cycle • The 2 three-carbon molecules from Glycolysis further break down through a series of chemical reactions into carbon dioxide molecules • Produces little ATP • Stage 2: Electron Transport • Energy-carrying molecules from Stage 1 move through a series of proteins making more ATP • Oxygen forms water at the end of Stage 2

  28. End Result of Cell Respiration • Up to 38 ATP molecules are made from 1 glucose molecule through cellular respiration • Many enzymes play important roles in the production of ATP

  29. Photosynthesis vs. Cellular Respiration • Photosynthesis makes sugars • Reactants are carbon dioxide and water • Products are oxygen and glucose • Cellular Respiration breaks down sugars • Reactants are oxygen and glucose • Products are carbon dioxide and water

  30. Photosynthesis vs. Cell Respiration

  31. 4.4 Vocabulary Check • 1. Which two terms are opposites? • Aerobic and Anaerobic • 2. Which term is a process that must happen in the cell’s cytoplasm before cellular respiration? • Glycolysis • 3. Which term is a process that happens within the mitochondria as part of cellular respiration? • Krebs Cycle

  32. 4. Which term is the name for this chemical equation? • Cellular Respiration • 5. In which organelle does cellular respiration take place? • Mitochondria • 6. What are the products and the reactants for cellular respiration? • Products: carbon dioxide, water • Reactants: glucose, oxygen

  33. 7. Where is most of the ATP made during cellular respiration? • In the inner membrane of the mitochondria during cellular respiration

  34. Section 4.6 Fermentation • When cells run low on oxygen for cell respiration, your cells can keep producing small amounts of ATP through glycolysis and fermentation. • Fermentation alone does NOT produce ATP but allows glycolysis to continue.

  35. Lactic Acid Fermentation • Occurs in your muscle cells • Fermentation recycles high energy molecules to the beginning of glycolysis in order for it to continue over and over • Glycolysis produces very little ATP temporarily until oxygen is available again in your cells.

  36. What molecule does fermentation provide to glycolysis? • ANSWER: • NAD+

  37. Fermentation Uses • Can help produce foods • Bacteria use fermentation in the digestive system where oxygen is not needed

  38. List three foods made through fermentation processes: • Cheese • Alcohol (Wine, Beer) • Sauerkraut • Bread • Yogurt

  39. 4.6 The Big Picture • 1. Fermentation alone does not make ATP. How does fermentation help a cell make ATP? • It allows very little ATP to be made from glycolysis over and over again • 2. What is lactic acid? • Acid that is produced from lactic acid fermentation in muscle cells when oxygen isn’t present for cellular respiration

  40. Chapter 4 Review • 1. What cellular process makes most of a cell’s ATP? • Cellular Respiration… why? • Oxygen is present for Electron Tranport where majority of ATP is made • 2. Do humans need photosynthesis to survive? Explain your answer. • Yes, humans get chemical energy (sugar/food) and oxygen from photosynthesis which are necessary for survival

  41. 3. Put the words in the flow chart: • Glycolysis -> Krebs Cycle -> Electron Transport • 4. Which of the descriptions below best describes cellular respiration? • A.) chemical energy is released when glucose is broken down into carbon dioxide • Which of the descriptions below best describes photosynthesis? • B.) Sunlight energy is stored in carbon-based molecules like glucose

  42. 6. Where in the cell does cellular respiration occur? • Mitochondria • 7. Where in the cell does photosynthesis occur? • Chloroplast

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