Cellular
Respiration
Cellular Respiration – 2 types
1. Anaerobic (without oxygen)
a) Glycolysis
b) Fermentation
2. Aerobic (with oxygen)
a) Kreb's cycle
b) Electron transport system
1. Anaerobic (without oxygen)
a) Glycolysis
Sugar is broken down
Takes place in cytoplasm in the cell
Input:
glucose (6 carbon molecule)
Output:
2 pyruvates (3 carbon molecules)
Net gain of 2 ATP’s
b) Fermentation
Input:
Pyruvates
Output:
Ethyl alcohol or lactic acid
CO2
NAD+
Examples:
Pain during exercise
Yeast in baking
Production of alcohol
2. Aerobic (with oxygen)
a) Kreb's cycle
(aka Citric Acid Cycle)
Takes place in matrix of mitochondria
Input:
2 pyruvate
Output:
4 CO2
2 ATP
some NADH and FADH2
b) Electron transport chain (ETC)
Occurs at the cristae of mitochondria
As electrons move, energy is given off
Produces lots ATP!
Input:
6 O2
Output:
6 H 2O
32 ATPs
Total Yield for
Aerobic Respiration
2 ATPs from Glycolysis
2 ATPs from Kreb’s Cycle
32 ATPs from ETC
NET TOTAL 36 ATPs!
Glycolysis
w/out Oxygen
Fermentation
w/ Oxygen
Kreb’s Cycle
Electron
Transport
System
The bulk of a cell's ATP must be produced in the
mitochondria.
To be energy efficient, particles must move through
the membrane with little energy expense.
Electron transport produces an uneven charge
on the mitochondria membrane. This allows
protons to move through the membrane by
electrical charge attraction.
Protons now move through the membrane
and are used by ATP synthase enzyme to
make ATP.
Photosynthesis Cell Respiration
Where?
Chloroplasts
Mitochondria
When?
Presence of light All the time
Input
CO2 & H2O
Glucose & O2
Output
Glucose & O2
CO2 & H2O
Energy
Source
Light
Chemical bonds
Energy
Result
Animal or
Plant
Energy stored
Energy released
Plants only
Both!