Cellular Respiration
Chapter 9
ATP
• a portable form of
energy “currency”
inside the cells.
The energy
released from ATP
powers chemical
reactions in your
cells.
• ATP releases energy
when the bond
between one of the 3
phosphates breaks,
forming ADP
(diphosphate). As the
bond breaks, energy
is released that the
cell can use.
• Photosynthesis stores energy in glucose.
– Occurs in plants and bacteria.
– In chloroplast.
• Cellular Respiration releases energy from glucose.
– Occurs in ALL living cells.
– In mitochondria.
•
Cellular Respiration Net Equation
6O2 + C6H12O6  6CO2 + 6H2O + Energy
• Three Stages
1. Glycolysis
2. Kreb’s Cycle
3. Electron Transport Chain
• The Main form of Energy produced = ATP
2 Types of Respiration
• Aerobicrequires oxygen
• Anaerobicdoes not require
oxygen (less
efficient)
Section 9-1
Chemical Pathways
Glucose
Glycolysis
Krebs
cycle
Fermentation
(without oxygen)
Go to
Section:
Electron
transport
Alcohol or
lactic acid
Respiration: An
Overview
Section 9-1
Mitochondrion
Electrons carried in NADH
Pyruvic
acid
Glucose
Glycolysis
Krebs
Cycle
Electrons
carried in
NADH and
FADH2
Electron
Transport
Chain
Mitochondrion
Cytoplasm
Go to
Section:
Aerobic Cellular Respiration
• Process in which a
glucose molecule
is broken down
and the energy it
contains is
released.
Flowchart
Section 9-2
Cellular Respiration
Glucose
(C6H1206)
+
Oxygen
(02)
Go to
Section:
Glycolysis
Krebs
Cycle
Electron
Transport
Chain
Carbon
Dioxide
(CO2)
+
Water
(H2O)
3 Stages to Cellular Respiration
1. Glycolysis- glucose
is partially broken
down to pyruvate
(yields 2 ATP) in
cytoplasm
2. Krebs Cycle pyruvate is
completely broken
down to CO2 (yields
2 ATP) in the
mitochondria
3. Electron
Transport
System- occurs in
the inner
membranes of the
mitochondria and
produces 34 ATP
–requires oxygen
Therefore: 1 molecule of glucose yields
38 ATP
in Aerobic Cellular Respiration
Chemical Equation for Cellular
Respiration
C6H12O6 + 6O2  6CO2 + 6 H2O +38 ATP
Anaerobic RespirationFermentation
• Lactic Acid
Fermentation-Muscle
cells can use this for
a short time to make
ATP in the absence of
necessary levels of
oxygen. This is the
reason muscles get
sore after a workout.
• Alcoholic
Fermentation—yeast
rely on this type of
respiration
• Wine and beer
contain ethanol made
during alcoholic
fermentation by yeast
• Both of these forms of anaerobic
respiration only yield 2 ATP per molecule
of glucose, so this type of respiration is
very inefficient.