Outline
I. Cellular Respiration
A.
B.
C.
Glycolysis
The Kreb’s cycle or (Citric Acid Cycle)
Electron Transport Chain
Cellular Respiration Overview
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Cellular Respiration is the process that releases
energy by breaking down food molecules in the
presence of oxygen.
Transformation of chemical energy in food into
chemical energy cells can use: ATP
These reactions proceed the same way in plants
and animals.
6O2 + C6H12O6  6CO2 + 6H2O + Energy
Oxygen + Glucose  Carbon Dioxide + Water +
Energy
Cellular Respiration Overview
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Breakdown of glucose begins in the cytoplasm in
the process of glycolysis
At this point the biochemical pathway can go in
one of 2 directions:
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Anaerobic cellular respiration (aka fermentation)
Aerobic cellular respiration
C.R. Reactions
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Glycolysis
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Series of reactions which break the 6-carbon glucose
molecule down into two 3-carbon molecules called
pyruvate
Process is an ancient one-all organisms from simple
bacteria to humans perform it the same way
Yields 2 ATP molecules for every one glucose
molecule broken down
Yields 2 NADH per glucose molecule (NAD is a
“cousin” of NADP – works the same way)
Occurs with or without oxygen
Aerobic Cellular Respiration
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Oxygen required=aerobic
Consists of two biochecmical pathways which
occur in a specialized structure within the cell
called the mitochondria
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1. Krebs Cycle
2. Electron Transport Chain
Kreb’s Cycle
•Operates under aerobic
conditions only.
•Converts the two-carbon
compound to C02
•Produces reduced coenzymes
NADH and FADH2 and ATP
directly
Production of pyruvate, & citric
acid cycle take place in matrix
Electron Transport Chain
1) Occurs mitochondria
2) A series of reactions where electrons are
passed one membrane-bound
protein/enzyme to another
3) 34 ATP are formed by this process.
4) The final electron acceptor is oxygen The
oxygen + 2 hydrogen = H20
Energy Tally
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36 ATP for aerobic vs. 2 ATP for anaerobic
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Glycolysis
2 ATP
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Kreb’s
2 ATP
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Electron Transport
34 ATP
38 ATP