Cellular Respiration
Converting Chemical Energy from Carbohydrates
into Chemical Energy of ATP
I. Cellular Respiration (Aerobic )
A.  Location - The reactions of aerobic respiration
occur in the mitochondria.
B. Products & Reactants of Aerobic
Respiration - 1
C.Overview of Aerobic Respiration - In the mitochondria of living things, oxygen helps the breakdown of sugars (glucose) to release energy useable by the
cell (ATP)
O2
Pyruvic acid
Mitochondria
Glucose
Glycolysis
1 gram
holds 3811
calories
H+
Krebs
Cycle
H 2O
CO2
2
Electron
Transport
Chain
34
2
D. A Closer Look at Aerobic Respiration
1. Glycolysis
• 
glucose (6 carbon sugar) breaks
down into pyruvic acid (3 carbon)
molecules and ATP (energy)
2
D. A Closer Look at Aerobic Respiration cont.
2. Kreb’s Cycle
• 
Pyruvic acid breaks
down into carbon
dioxide (1 carbon)
and ATP (energy) 3. Electron Transport Chain
• 
electrons generated
during glycolysis
and Kreb’s cycle
together with oxygen
form water and
release energy
E.  Energy Released through
Cellular Respiration 1. ATP
• 
36 ATP units are released
from one glucose unit
• 
A unit of glucose
molecules contains 686
kcal of stored energy. A
unit of ATP stores 7.5 kcal.
If 36 ATP units are released
from the breakdown of
glucose, how efficient is
the transformation from
energy stored in glucose to
energy released as ATP?
3
II. Relationships
A.  Aerobic Cellular Respiration and Breathing • 
Oxygen is required for the electron transport
chain to operate and ATP to be synthesized.
• 
Oxygen is taken in by humans as we breathe
and carbon dioxide is released. B. Aerobic Cellular Respiration and Photosynthesis
• 
These are “opposite processes”. • 
The products of photosynthesis
are the reactants of respiration
and vice versa. • 
Energy stored through
photosynthesis is released
through cellular respiration 4