Cellular Respiration
Cellular Respiration
Cellular Respiration is the process
that releases energy by breaking
down food molecules in the presence
of oxygen. This occurs in the
mitochondria.
6O2 + C6H12O6  6CO2 + 6H2O +
Energy
Oxygen + Glucose  Carbon Dioxide
+ Water + Energy
You Write:
Cellular respiration- release energy by
breaking down food in the presence of
oxygen.
6O2 + C6H12O6  6CO2 + 6H2O + Energy
(oxygen + glucose  carbon dioxide +water+energy)
So what is the purpose of cellular
respiration?
Cellular Respiration
Glycolysis
Glycolysis is the process in which one
molecule of glucose is broken in half,
producing two molecules of pyruvic
acid.
2 ATP needed to start reaction, 4
ATP are produced thus the net gain
is 2 ATP.
You write:
Glycolysis is the process of splitting 1
glucose molecule to form 2 pyruvic
acids, releasing 2 ATP.
Fermentation
Releases energy from glucose without the
presence of oxygen—allows glycolysis to
continue to supply ATP.
There are two types of fermentation:
alcoholic and lactic acid.
Alcoholic fermentation --yeasts and some
microorganisms. -- produces alcohol &
Carbon Dioxide
Lactic Acid -- produced by muscles during
rapid exercise when the body cannot
supply enough oxygen.
You write:
Fermentation allows glycolysis to
continue when there is no oxygen.
This is called anaerobic respiration.
The two types are
– alcoholic fermentation(yeast)
– Lactic acid fermentation (animals)
The Krebs Cycle
If oxygen is present-pyruvic acid is broken down into
carbon dioxide and makes ATP.
Citric Acid is created in this cycle
giving it the nickname Citric Acid
cycle.
Net ATP Production is 2 ATP.
You write:
Krebs cycle—pyruvic acid is broken
down to produce 2 ATP when oxygen
is present. CO2 is released.
Electron Transport Chain
The electron transport chain uses the
high-energy electrons from the Krebs
Cycle to convert ADP to ATP.
Total ATP 32.
You write:
Electron transport chain releases 32
ATP using electrons from the Krebs
cycle.
--2 ATP
--2 ATP
--32 ATP
Totals
Gycolysis 2 ATP
Krebs Cycle 2 ATP
Electron Transport Chain 32 ATP
Total = 36 ATP
So, what is ATP
Energy & Exercise
Quick energy – Lactic Acid
fermentation is used to get quick
energy and gives off lactic acid as a
by-product, thus the muscle pain.
Long-Term Energy – Use cellular
respiration to produce energy.
Exercising or activities that last for at
least 15 to 20 minutes. Best form for
weight control.
Comparing Photosynthesis &
Respiration
Photosynthesis
Cellular
Respiration
Function
Energy Storage
Location
Chloroplasts
Energy
Release
Mitochondria
Reactants
CO2 and H2O
Products
C6H12O6 and O2
C6H12O6 and
O2
CO2 and H2O
Equation
6CO2 + 6H2O 
C6H12O6 + 6O2
C6H12O6 + 6O2
6CO2 + 6H2O
Your turn….
1. In your own words, what is cellular
respiration?
2. Compare and contrast the equation
for cellular respiration and the
equation for photosynthesis.
3. Of plants and animals, which ones
undergo cellular respiration and
which ones photosynthesize?