1. Cellular Respiration Part II
College Prep
Natural Science
Flora 2008

2. Food Into Energy
Cellular Respiration is the process that all cells use to break down glucose to yield the energy that cells need to function…….
C.R. can occur with or without oxygen
w/out oxygen is called anaerobic respiration
w/oxygen is called aerobic respiration

3. Aerobic Respiration Glycolysis Krebs Cycle Electron Transport Chain
The result/goal of all of these processes is to produce ATP which gives the cells energy

4. Glycolysis
Process by which a 6-carbon glucose molecule is broken down into two 3-carbon pyruvate molecules
Occurs in the cytoplasm
Small amounts of ATP and NADH are produced
ATP – energy transport molecule
NADH is a hydrogen and energy carrier
** If oxygen is present, then pyruvate enters the Krebs Cycle

5. Krebs Cycle
Begins with pyruvate and is transported to the mitochondria
CO2 is released out of the pyruvate and more ATP and NADH are produced
CO2 is released from the cell as gas
Since glycolysis produced two pyruvate molecules, two turns of the Krebs cycle are required to break down both pyruvate molecules

6. Electron Transport System
Uses NADH from the previous stages and these molecules carry hydrogen and energy
“ETS” has a series of electron carrier molecules embedded in the inner membrane of the mitochondria
As the electrons move from one carrier to the next they release energy
With the energy they release, some of the protons are pumped across the membrane creating a concentration gradient

7. Cont. “ETS”
As the protons diffuse back across the membrane they pass through and enzyme complex that synthesizes/makes ATP
The electrons and protons then join oxygen gas to form water
This is the greatest ATP production process of all the three stages

8. Summary of Aerobic Respiration
Sugar + Oxygen →
Carbon Dioxide + water + ATP (energy)

9. Anaerobic Respiration
Glycolysis takes place
Pyruvate is converted into other molecules and the Krebs cycle and the electron transport system do not occur - ** This is called fermentation
Does not produce near as much energy as aerobic respiration, but gets some animals by when they need energy!
Like you and me!!

10. Homework
Stop and Think (1-5)
Page 344