1. Ch. 9 Cellular Respiration
Food and drink provide a source of energy for your cells that is used to make ATP
calorie – the amount of energy needed to raise one gram of water one °C
Kilocalorie (on labels) – 1000 calories
Food provides the building blocks for your cellular products (proteins, hormones, etc.)

2. Overview of C. R.
Cellular respiration can be aerobic (with O2) or anaerobic (without O2)
Aerobic respiration has 3 steps:
1. Glycolysis
2. Krebs Cycle
3. Electron
Transport Chain

4. Equation for C. R.
6O2 + C6H12O6  6CO2 + 6H2O + ATP
(36-38)
Oxygen and Glucose react forming carbon dioxide, water and ATP
Other sugars, starch, fats and proteins can also be used as energy sources.
Glucose is the simplest energy form
***Some energy released as heat

5. Glycolysis (splitting glucose)
Occurs in the cytoplasm
One glucose molecule split into two molecules of pyruvic acid
Uses 2 ATP but makes 4 ATP.
ATP net gain = _____
Makes 2 NADH
Does NOT require oxygen

7. Let’s review…. Write the reaction equation for cellular respiration.
What is the first step of C.R. called?
Where does this step take place?
What is broken down/What is formed?
What is the net gain for ATP?
Is oxygen needed?

8. The Krebs Cycle In the matrix of the mitochondria
Pyruvic acid enters the cycle, where a series of enzyme-controlled reactions create NADH and FADH (energy carriers)
Carbon dioxied (CO2) is a waste product

10. The Electron Transport Chain
H+ ions made in Krebs cycle build up outside the inner mitochondrial membrane
The H+ ions are forced through ATP synthase making 3 ATPs for each turn

12. E.T.C. Oxygen is used as the final electron acceptor
H+ and oxygen combine to form water (a waste product)
Without oxygen the process backs up and ATP can’t be made

13. Summary of Cellular Respiration
Glucose is split into _________________ in the cytoplasm
In the mitochondria, the _____________ makes CO2 and NADH and FADH
___________________ makes ATP on the inner membrane of the mitochondria
Oxygen and hydrogen make water
Total – 36 ATPs made by aerobic resp.

14. Anaerobic Respiration
If your body uses energy very quickly, pyruvic acid can build up
ATP is produced anaerobically by turning the pyruvic acid into lactic acid
Lactic acid builds up in muscles and hurts!
Intake of oxygen (heavy breathing) removes lactic acid from your muscles

15. Lactic Acid Fermentation Pyruvic acid + NADH  lactic acid + NAD+

16. Alcoholic Fermentation
Fermentation is a valuable anaerobic process used to make ATP by yeasts and bacteria
Fermentation produces CO2 and ethyl alcohol as by-products

17. Alcoholic Fermentation
Pyruvic acid + NADH 
alcohol + CO2 + NAD+

18. *Fermentation releases energy from food molecules by making ATP w/o oxygen
Unicellular organisms produce L.A.
Valuable in food/drink industry: yogurt, cheese, sauerkraut, pickles