1 / 28

CHAPTER 9 - CELLULAR RESPIRATION

CHAPTER 9 - CELLULAR RESPIRATION. CELLULAR RESPIRATION. Process that releases energy by breaking down food molecules in the presence of oxygen 6 O 2 + C 6 H 12 O 6 --> 6 CO 2 + 6 H 2 0 oxygen + glucose --> carbon dioxide + water + energy. 3 Stages of Cellular Respiration. Glycolysis

gigi
Download Presentation

CHAPTER 9 - CELLULAR RESPIRATION

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. CHAPTER 9 - CELLULAR RESPIRATION

  2. CELLULAR RESPIRATION • Process that releases energy by breaking down food molecules in the presence of oxygen • 6 O2 + C6H12O6 --> 6 CO2 + 6 H20 • oxygen + glucose --> carbon dioxide + water + energy

  3. 3 Stages of Cellular Respiration • Glycolysis • Krebs Cycle • Electron Transport Chain • Each stage captures some of the chemical energy available in food molecules and uses it to produce ATP

  4. Energy Molecules of Cellular Respiration • In cellular respiration, several molecules are used as energy carriers. These molecules carry energy from one step of cellular • ADP + P = ATP • NAD + H = NADH • FAD+ + H2 = FADH2

  5. GLYCOLYSIS • Glycolysis– First step in releasing the energy of glucose. • A molecule of glucose is broken into two molecules of pyruvic acid (a 3-carbon compound). • takes place in the cytoplasm • does not require oxygen - anaerobic

  6. GLYCOLYSIS • Requires: 1 Glucose molecule (C6H12O6), 2 ATP • Produces: 2 ATP, 2 NADH and 2 pyruvic acid

  7. Second Stage: Fermentation or Krebs Cycle • Glycolysis can be followed by fermentation or the Krebs cycle depending if oxygen is present. • Fermentation will occur if no oxygen is present. • Krebs Cycle will occur if oxygen is present.

  8. Glycolysis Fermentation Krebs Cycle Anaerobic (no oxygen) Aerobic (oxygen)

  9. Without Oxygen - Fermentation • Anaerobic - without the presence of oxygen • Fermentation - releases energy from food molecules in the absence of oxygen • two types: Alcoholic and Lactic Acid Fermentation • Occurs in the cytoplasm

  10. Types of Fermentation • Alcoholic - causes bread to rise, used to make beer and wine • Lactic Acid - produced in muscles during rapid exercise when body can’t supply enough O2 • causes painful, burning sensation and muscle soreness

  11. With Oxygen - Kreb’s Cycle • Aerobic - in the presence of oxygen • Kreb’s Cycle also called Citric Acid Cycle • Kreb’s Cycle - 2nd stage of cellular respiration, in which pyruvic acid is broken down into CO2 in a series of energy-extracting reactions, creating energy molecules. • Occurs in the mitochondria

  12. Kreb’s Cycle • Requires: 1 Pyruvic Acid • Produces: CO2, NADH, FADH2, ATP

  13. Kreb’s Cycle • As a pyruvic acid molecule enters the mitochondria, a carbon is removed, forming CO2. • Carbons continue to be rearranged, releasing more CO2, while allowing the energy carriers to be charged. • This cycle will happen twice for every molecule of glucose broken down in glycolysis.

  14. Third Stage: Electron Transport Chain • The electron transport chain uses the high-energy electrons from the Krebs cycle to convert ADP into ATP. • Occurs in the mitochondrial matrix.

  15. Electron Transport Chain (ETC) • Requires: NADH, FADH2, ADP • Produces: H2O, NAD, FAD, ATP

  16. Electron Transport Chain • The Krebs Cycle generates high-energy electrons that are passed to NADH and FADH2. • The high-energy electrons (H+) from NADH and FADH2 are used up and passed along the proteins in the ETC.

  17. Electron Transport Chain • Oxygen serves as the final electron acceptor forming a water molecule. • As H+ ions move through the ETC, ATP synthase spins adding ADP to P forming ATP.

  18. Cellular Respiration Totals • 1 molecule of glucose produces: • 2 ATP in glycolysis • 34 ATP in Kreb’s Cycle and Electron Transport Chain • water • CO2

  19. Types of Energy • Quick Energy - Muscles only contain enough ATP for a few seconds of intense activity. Then, muscle cells produce their ATP by lactic acid fermentation. • Long Term Energy - Cellular Respiration is the only way to generate a continuing supply of ATP • energy is released more slowly than fermentation, which is why athletes have to pace themselves • 15 to 20 min. of activity from carbohydrate stored in the body • after 20 min., energy comes from break down of fats

  20. Photosynthesis vs. Respiration • Photosynthesis and cellular respiration take place in opposite directions! Photosynthesis: Use light energy to build a sugar. carbon dioxide + water + light energy → sugars + oxygen Respiration: Break down sugar to release energy. oxygen + sugars → carbon dioxide + water + energy

  21. Photosynthesis vs. Respiration • Photosynthesis: • Use light energy to build a sugar. • Process that “deposits” or captures energy. • Removes carbon dioxide from the atmosphere. • Releases oxygen into the atmosphere.

  22. Photosynthesis vs. Respiration • Respiration: • Break down sugar to release energy. • Process that “withdraws” or releases energy. • Removes oxygen from the atmosphere. • Releases carbon dioxide into the atmosphere.

More Related