Chapter 9: Cellular Respiration Essential Questions:

1
Chapter 9 Cellular RespirationEssential
Questions

• What is glycolysis?
• What is cellular respiration?
• What are the 2 main types of fermentation?
• How are energy exercise related?

2
Chapter 9-1 Chemical Pathways

• Chemical Energy Food
• Glycolysis releases small amt. of energy from
  glucose, but if O2 present, leads to other
  pathways that can release lots of energy

3

• Overview of Cellular Respiration
• CR releases energy by breaking down food
  molecules in the presence of O2
• 6 O2 C6H12O6 ? 6 CO2 6 H2O energy
• Energy must be released slowly to be effective

4

• Glycolysis doesnt require oxygen
• ATP production 2 ATP molecules per molecule of
  glucose
• NADH production NAD accepts electrons to form
  NADH cell runs out of NAD quickly, though

5

• Fermentation if oxygen not present anaerobic
• Releases energy from food, converts NADH to NAD
  so glycolysis can continue

6

• Alcoholic fermentation yeasts, etc.
• Lactic acid fermentation regenerates NAD so
  glycolysis can continue
• Lactic acid produced in muscles when body cant
  supply enough oxygen during heavy exercise

7
9-2 Krebs Cycle and Electron Transport

• Krebs Cycle aerobic happens if oxygen present
• Pyruvic acid broken down into CO2 in series of
  energy-extracting rxns.
• Happens in mitochondrion

8

• Electron transport uses electrons from Krebs
  Cycle to convert ADP to ATP
• Oxygen accepts electrons
• The totals
• Anaerobic 2 ATP per glucose
• Aerobic 36 ATP per glucose
• 38 of energy of glucose utilized (other 62
  released as heat)

9

• Energy exercise
• Quick energy lactic acid fermentation ( 90
  sec. of energy)
• Long-term energy CR
• CR releases energy more slowly than fermentation
• Body stores energy in muscle tissues as glycogen
• Lasts 15-20 min
• After that body breaks down fats

10

• Comparing Photosynthesis and CR
• Almost opposite processes
• See top of p. 232