Biology: Chapter 6 & 7

• Cellular Respiration


  The main way that chemical energy is harvested from food and converted to ATP
• Aerobic


  Cellular respiration is an aerobic process - it requires oxygen
• Cellular respiration


  1. Cells take in oxygen gas

  2. Cells release waste carbon dioxide gas

  3. Breathing exchanges these same gases between the blood and outside air
• Glucose


  A common fuel molecule for cellular respiration
• Cellular respiration can produce up to 32 ATP molecules for each glucose molecule (after losses)
• Cellular respiration


  1. Glycolysis

  2. Citric acid cycle (Krebs Cycle)

  3. Electron transport chain
• Cellular respiration can generate up to 32 molecules of ATP per molecule of glucose
• Fuels for cellular respiration

  • Diverse types of carbohydrates
  • Fats
  • Proteins
• Fermentation


  The anaerobic (without oxygen) harvest of food energy
• Fermentation in human muscle cells

  1. Glycolysis produces 2 ATP

  2. Pyruvic acid is reduced by NADH, producing NAD+

  3. Lactic acid is a by-product
• Products of fermentation by microorganisms

  • Cheese, sour cream, and yogurt
  • Soy sauce, pickles, and olives
  • Sausage meat products
• Alcoholic fermentation


  Fermentation by yeast that produces CO2 and ethyl alcohol instead of lactic acid
• Products of alcoholic fermentation

  • Beer
  • Wine
  • Breads
• Photosynthesis


  The process where sunlight energy combined with water and carbon dioxide will produce sugar and oxygen
• Chloroplasts


  • The site of photosynthesis
  • Found mostly in the interior cells of leaves
  • Contain interconnected sacs called thylakoids suspended in a fluid called stroma
  • Thylakoids are concentrated in stacks called grana
• Chlorophyll


  A light-absorbing pigment that plays a central role in harvesting solar energy
• Stomata


  Tiny pores on the underside of leaves where carbon dioxide enters and oxygen exits
• Photosynthesis


  1. Light reactions convert solar energy to chemical energy

  2. Calvin cycle uses the products of the light reactions to make sugar from carbon dioxide
• The simplified equation for photosynthesis is that sunlight energy combined with water and carbon dioxide will produce sugar and oxygen