1. Chapter 7 pgs 131-147 Food to energy
Cellular Respiration
Chapter 7 pgs
Food to energy

2. Harvesting Chemical Energy
From photosynthesis we get carbohydrates (glucose)
Cellular respiration: Breaking down the carbohydrates (glucose) to make ATP and NADH
NADH is an electron carrier
Starts with glycolysis
Glyco = sugar
Lysis = breaking
Breaking down sugars

3. What happens after Glycolysis?
Chemicals can take one of two pathways
Anaerobic (no oxygen present) fermentation
Makes no ATP, but keeps the cycles going
Aerobic respiration
Makes a lot of ATP

4. Glycolysis
1 six carbon glucose broken down into 2 three carbon pyruvic acid molecules
Happens out in the cytoplasm

5. What happens next depends on whether there is oxygen present or not.

6. Fermentation
If there is no oxygen some cells can convert pyruvic acid into other compounds and get some more NAD+
No ATP is made, but the NAD+ can keep Glycolysis going to make a little ATP
2 kinds of fermentation: Lactic acid fermentation and Alcoholic Fermentation

7. Lactic Acid Fermentation
Converting pyruvic acid to Lactic acid
A.K.A. milk acid
Bacteria are used to do this to get cheese, yogurt, and sour cream
Under heavy exercise you use up Oxygen faster than you can replace it
Lactic Acid builds up and the acidity causes fatigue, pain and cramps.

8. Alcoholic Fermentation
Yeast convert pyruvic acid into ethyl alcohol
They break a CO2 off of pyruvic acid
The 2 carbon sugar left behind forms ethyl alcohol
Basis of wine and beer industry, and bread making

9. Efficiency of Glycolysis
Compare the kilocalories of Glucose with the kilocalories in the ATP that is made.
The 2 ATP molecules made during glycolysis receive only 2% of the energy in glucose
Where does the rest go?
It’s still in pyruvic acid
This small amount of energy is enough for bacteria, but more complex organisms need more of glucoses energy.

10. Objectives Define Cellular respiration
Describe the major events in glycolysis
Compare and contrast lactic acid fermentation and alcoholic fermentation
Calculate the efficiency of glycolysis