Chapter 9: Cellular Respiration

1
Chapter 9 Cellular Respiration

• Section 1 Chemical Pathways

2
Objectives

• 1. Explain the process of cellular respiration
• 2. Describe what happens during the process of
  glycolysis.
• 3. Name the 2 main types of fermentation

3
Overview of Cellular Respiration

• The process that releases energy by breaking down
  glucose and other food molecules in the presence
  of oxygen
• Occurs in 3 stages
• 1st - cytoplasm
• 2nd and 3rd in the mitochondria

4
Overview of Cellular Respiration

• 6 O2 C6H12O6 6 CO2 6 H2O
• Oxygen Glucose
  carbon water
• 
  dioxide
• Produces the needed energy to perform cellular
  functions

5
Overview of Cellular Respiration

• 1st stage Glycolysis cytoplasm
• 2nd stage Krebs cycle mitochondria
• 3rd stage Electron transport chain - mitochondria

6
Glycolysis

• The process in which one molecule of glucose is
  broken in half, producing 2 molecules of pyruvic
  acid
• Occurs in the cytoplasm

7
Glycolysis

• In the process, 2 ATP and 2 NADH are produced
• The 2 molecules of pyruvic acid and the 2 NADH
  are used in the Krebs cycle
• 2 NADH are electron carriers which transport high
  energy electrons to the electron transport chain

8
Fermentation

• The release of energy in the form of ATP without
  oxygen
• Anaerobic (without oxygen)
• Follows glycolysis
• 2 main types
• Alcoholic fermentation
• Lactic acid fermentation

9
Alcoholic Fermentation

• Pyruvic acid NADH Alcohol CO2 H2O
• Most commonly used by yeast in breads
• The excess CO2 is responsible for the rising of
  the bread

10
Lactic Acid Fermentation

• Pyruvic acid NADH Lactic acid NAD
• Occurs in human muscles in the absence of oxygen
  - rapid exercise
• Produces a painful, burning sensation and sore
  muscles
• Also occurs in the production of cheese, yogurt,
  sour cream, pickles, and sauerkraut