Cellular Respiration

Cellular Respiration
Cellular Respiration
 Respiration is the slow controlled release
of energy from food.
 The energy released is used to fuel all
metabolic activities in the organism.
 The process takes place in many steps all of
which is controlled by enzymes.
Aerobic Respiration
The process by which glucose is oxidised in
many small steps to give carbon dioxide and
C6H12O6 + 6O2
+ Oxygen
6CO2 + 6H20 + Energy
Carbon + Water
+ Energy
ADP + P(Phosphate) + Energy
Energy (released)
ADP = Adenosine Di Phosphate
ATP = Adenosine Tri Phosphate.
Is found in all cells
Yields large amounts of energy
Drives the thousands of biological processes needed to sustain life
eg. Growth, movement, reproduction.
Green plants use light energy to manufacture ATP as part of the
process of Photosynthesis
In Animals, ATP is formed by the breakdown of glucose molecules in
Summary of important events taking place in
aerobic respiration
1.Glucose (or fat) is used as a substrate to
provide energy
2.Energy is released in a slow, controlled
3.The energy released is temporarily stored in
4.Oxygen is used in the process
5.Carbon dioxide and water is released
Anaerobic Respiration
In anaerobic respiration the food is broken down without
oxygen in animals to form lactic acid and ethanol in plants and
Lactic acid build up is toxic in animals and needs to be broken
down. It usually builds up during strenuous exercise when
oxygen is short (Oxygen debt).
Plants and Yeast
ethyl alcohol + Carbon Dioxide + Energy
+ 2 CO2
Lactic acid + Energy
Oxygen Debt
This occurs when the lungs cannot supply all the oxygen that the muscles
need eg. During vigorous exercise.
In such a situation the muscles can continue to break down glucose to
liberate energy for a short time using anaerobic respiration
This produces lactic acid
At certain levels in the muscles lactic acid causes the sensation of fatigue
Once vigorous exercise stops the accumulated lactic acid must be broken
down, this uses up extra oxygen
Panting or Yawning usually allows the body to take in this excess oxygen
to ‘pay off’ the oxygen dept
Summary of events taking place in anaerobic
1. No oxygen is used
2. Little energy is produced
3. Alcohol and carbon dioxide are produced
by plants and yeast
4. Only lactic acid is produced by animals
Industrial & Domestic Applications of
Anaerobic Respiration
Yeast uses sugar as food and makes ethanol as a by
product of the reaction. Ethanol is found in beers,
wine and sprits like whiskey and rum.
Fermentation of bacteria (lactobacillus) in the
production of yogurt and cheese
The carbon dioxide produced by yeast is what
makes bread, pastries and cakes light and fluffy
Site of Cellular Respiration
Site of cellular respiration
Diagrams of Mitochondria found in all eukaryotic cells
An Organelle found in cells
Contains enzymes responsible for energy production
during aerobic respiration
Found in both plant and animal cells

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