Cellular Respiration
Chapter 9
Cellular Respiration
(Opposite of Photosynthesis)
• Overall equation:
– C6H12O6 + 6O2
(glucose +
oxygen)

6CO2 + 6H2O + energy
(carbon dioxide + water)
• Releases energy by breaking down glucose
• Occurs in all cells in all living things
(Plants go through cellular respiration at night)
• In the presence of oxygen, cellular
respiration produces a total of 36 ATP
molecules per glucose.
2 Types of Cellular Respiration
• 1. Aerobic respiration – does require
oxygen
– Occurs in the mitochondria
– Produces more ATP (34)
2. Anaerobic respiration- does NOT
require oxygen
-Occurs in the cytoplasm
-Produces less ATP (2)
Three Stages of Cellular Respiration
1. Glycolysis
(takes place in the cytoplasm)
2. Krebs Cycle
(takes place in the mitochondria)
3. Electron Transport Chain
(takes place in the mitochondria)
Cellular Respiration
Glycolysis
• 1st stage
• Takes place in the cytoplasm
• Has a total of 2 ATP
(Produces 4 ATP but uses 2 ATP)
• Anaerobic respiration (no oxygen)
Krebs Cycle
(AKA: Citric Acid Cycle)
•
•
•
•
2nd stage
Takes place in mitochondria
Produces 2 ATP
Aerobic Respiration (requires oxygen)
Electron Transport Chain
•
•
•
•
3rd stage
Takes place in the mitochondria
Produces 32 ATP
Aerobic Respiration (requires oxygen)
Cellular Respiration
Occurs in
cytoplasm
Glucose
Glycolysis
Occurs in
mitochondria
Krebs
Cycle
+
Oxygen
2 ATP
anaerobic
Electron
Transport
Chain
32 ATP
2 ATP
Carbon
dioxide
=
+
Water
+
36 ATP
aerobic
Anaerobic Respiration
 Fermentation: releases ENERGY from FOOD by
producing ATP in the ABSENCE of OXYGEN
• Breaks down GLUCOSE (SUGAR)
• Does NOT require oxygen
1. Alcoholic fermentation
– Occurs in yeast cells
– Produces 2 ATP, carbon dioxide and alcohol
– Carbon dioxide causes bread to rise
2. Lactic Acid fermentation
– Occurs in muscle cells
– Produces 2 ATP, carbon dioxide and lactic acid
– Lactic acid causes muscle soreness
• 1. Alcoholic fermentation
2. Lactic Acid fermentation
Cellular Respiration Review/Close
aerobic
muscle
anaerobic
Lactic Acid fermentation
mitochondria
36
Alcoholic fermentation
cellular respiration
1.________ is the process that releases energy by breaking down molecules in food.
*Cellular Respiration
2.When food is broken down in the presence of oxygen it is called _________.
*Aerobic
3. Aerobic respiration takes place in the ___________.
*Mitochondria
4. Overall, a total of ____ ATP molecules are produced during aerobic respiration.
*36
5. __________ respiration takes place in the absence of oxygen.
*Anaerobic
6. Two types of anaerobic respiration are __________, which takes place in yeast cells
and _________ which takes place in muscle cells.
*Alcoholic fermentation
*Lactic Acid fermentation
Comparing Photosynthesis and Cellular Respiration
Photosynthesis
Cellular Respiration
Function
Stores Energy
Energy release
Location
Chloroplast
Mitochondria
Reactants
Carbon dioxide and Glucose and oxygen
water
Glucose and oxygen Carbon dioxide and
water
Products
Equation
6CO2+6H2O+light
 6O2+C6H12O6
6O2+C6H12O6 
6CO2+6H2O+energy
Plants
Animals
(producers)
(all organisms)
1.
2.
3.
4.
What is the purpose of photosynthesis? What is the
purpose of cellular respiration?
Where does photosynthesis occur? Cellular
respiration?
Describe what would happen if the amount of sunlight
available to a plant became limited. How would that
affect cellular respiration?
What are the reactants in each of these equations?
What are the products?