1. Key Words anaerobic process: does not require O2 to occur
aerobic process: requires O2 to occur
glycolysis: biochemical pathway that breaks down glucose into pyruvic acid
pyruvic acid: 3-carbon molecule made from glucose during glycolysis
NADH: an energy-carrying molecule
fermentation: another pathway that converts glucose into ATP

2. What is Cellular Respiration?
how cells receive energy from nutrients
breaks down organic molecules (ex: sugars) into ATP
occurs in mitochondria (therefore, this occurs in both plants AND animals)

3. Equation for Cellular Respiration
C6H12O O CO H20
(glucose) (oxygen) (carbon dioxide) (water)
------>
REACTANTS
(starting materials)
PRODUCTS
(end result)

4. Stages of Cellular Respiration
Stage 1 – GLYCOLYSIS
uses glucose made during photosynthesis
breaks down glucose into 2 molecules of pyruvic acid
in the process, a small amount of ATP and NADH is made
What comes next depends on one factor…
the presence of OXYGEN.

5. Stage 2 NO, there is not O2 present: YES, there is O2 present:
Stage 2 = FERMENTATION
creates lactic acid or ethyl alcohol
these can be converted to ATP
inefficient process (wastes energy)
Stage 2 = AEROBIC RESPIRATION
Has two stages:
Krebs Cycle
Electron Transport Chain (ETC)

6. Krebs Cycle Picks up where glycolysis left off.
Takes 2 molecules of pyruvic acid (made in glycolysis), converts them into various molecules over several cycles
involves enzymes such as Co-enzyme A
Pyruvic acid is converted into Acetyl CoA via enzymes. When this occurs, CO2 is produced.
End result: 2 molecules of ATP made in each cycle
One glucose molecule will fuel two Krebs Cycle (therefore, 1 glucose -> 4 ATP)

7. Electron Transport Chain
similar to photosynthesis
occurs on the inner membrane of mitochondria
transfers electrons throughout several molecules, building up energy
when enough energy is built up (from NADH and FADH2), ATP is created
NADH and FADH2 created during the Krebs Cycle
chemiosmosis = production of ATP via chemicals