This document provides an overview of cellular respiration and its three main stages: glycolysis, the Krebs cycle, and the electron transport chain. It begins by asking multiple choice and true/false questions about glycolysis and cellular respiration. It then discusses that glycolysis yields 2 ATP molecules net and produces NADH. When oxygen is absent, fermentation occurs instead of the later respiration stages, producing either lactic acid or ethanol. Glycolysis is common to both fermentation and cellular respiration as it breaks down glucose to pyruvic acid.

1. Biology 10
CELLULAR
RESPIRATION

2. POP QUIZ
• 1. The process of cellular respiration begins with _______________.
• 2. ____________ and _____________ are the reactants for cellular
Respiration.
• 3. Glycolysis breaks down ______________ molecules.
• 4. How many ATP molecules are needed to start Glycolysis
• 5. How many ATP molecules are made by the end of glycolysis?
• 6. T or F: Animals cannot photosynthesize.
• 7. T or F: Plants undergo Cellular Respiration.
• 8. What is the energy needed to raise 1 g of water by 1 degree
Celsius?
• When no oxygen (anaerobic) is present, this pathway follows
glycolysis.

3. Living things get the energy they need
from food. Both plants and animal cells
carry out the final stages of cellular
respiration in the mitochondria

4. Chemical Energy and Food
• How much energy is actually present in food?
• One gram of the sugar glucose (C6H12O6), when burned in the
presence of oxygen, releases 3811 calories of heat energy.

5. What is a calorie?

7. Cellular Respiration Begins….
• There are three stages of cellular respiration
• Glycolysis
• The Krebs Cycle
• The Electron Transport Chain

8. Glycolysis

9. Glycolysis and Cellular Respiration

10. Glycolysis
 ATP Production
 Add 2 molecules of ATP to start process
Investment: 2 ATPs
Final balance: 4 ATPs
Net gain: 2 ATPs

11. NADH Production

13. GYLCOLYSIS RECAP
 glucose oxidized yields pyruvic acid
 reactions take place in cytosol
 NAD+ to NADH (electron acceptor)
 Pyruvic acid yields 4 ATP but 2 used in process (so net yield is 2
ATP)

14. Fermentation
• When oxygen is NOT present, glycolysis is followed by a different
pathway: Fermentation.

15. Alcoholic Fermentation

16. Drunk Squirrel

17. Lactic Acid Fermentation

18. Sauerkraut

19. Fermentation
•fermentation is the formation of alcohol from
sugar.
•Occurs in cytosol when “NO Oxygen” is
present (called anaerobic).
•Remember: glycolysis is part of
fermentation.
•Two Types:
1. Lactic Acid (animal cells)
2. Alcohol (plant cells)

20. Lactic acid fermentation
•NADH oxidized to NAD+
e.g. Yogurt, cheese
•*in muscle – not enough oxygen so switch
to anaerobic respiration b/c oxygen is
depleted which makes cytosol acidic so
produces cramps

21. Lactic Acid Fermentation
Animals (pain in muscle after a workout).
2 Lactic
acid
2NADH 2 NAD+
C
C
C
Glucose
Glycolysis
C
C
C
2 Pyruvic
acid
2ATP
2ADP
+ 2
2NADH
P
2 NAD+
C
C
C
C
C
C

22. Lactic Acid Fermentation
End Products: Lactic acid fermentation
2 - ATP (phosphorylation)
2 - Lactic Acids

23. Alcoholic Fermentation
•convert pyruvic to ethyl alcohol by
removing CO2
e.g. bread, beer, wine - need enzymes in
yeast

24. Alcohol Fermentation
Plants and Fungi  beer and wine
glucose
Glycolysis
C
C
C
C
C
C
C
C
C
2 Pyruvic
acid
2ATP
2ADP
+ 2
2NADH
P
2 NAD+
C
C
2 Ethanol2CO2
released
2NADH 2 NAD+

25. Alcohol Fermentation
•End Products:
2 - ATP (phosphorylation)
2 - CO2
2 - Ethanol’s

26. •glycolysis is not efficient but unicellular
organisms don’t need much energy to function
•E.g. paramecium, ameoba
•probably evolved early in history of life

27. • kilocalories – 1 kcal = 1000 cal