1. Cellular Respiration

2. ATP: Universal Energy Source
Autotrophs get their energy from the sun
Heterotrophs get their energy from plants or other organisms
Regardless, the energy is converted to the chemical energy of ATP

3. Making ATP Plants make ATP during photosynthesis
Cells of all organisms make ATP by breaking down
Carbohydrates
Fats
Proteins

4. 2 Main Types of Energy-Releasing Pathways
Anaerobic pathways
Evolved first
Don’t require oxygen
Start with glycolysis in cytoplasm
Completed in cytoplasm
Aerobic pathways
Evolved later
Require oxygen
Start with glycolysis in cytoplasm
Completed in mitochondria

5. Summary Equation for Aerobic Respiration
C6H O CO2 + 6H20
The equation is the opposite of the equation for photosynthesis.
Respiration Summary
Aerobic Respiration
3 stages
1.) Glycolysis
2.) Citric Acid Cycle (Krebs Cycle)
3.) Electron Transport Chain

7. Glycolysis Occurs in the cytoplasm
Glucose is broken down (sugar breaking)
Hydrolysis reaction
Catabolic reaction
Exothermic

8. Glycolysis 2 Stages Energy Requiring
Chapter 8
Cellular Energy
Glycolysis
2 Stages
Energy Requiring
ATP
Needed to break apart the bonds of glucose
Energy Releasing
Needed to split glucose into 2 three-carbon pyruvate molecules
Most of the energy from the glucose is still contained in the pyruvate.
ATP and NADH (electron carrier) form as a result of the breakdown of glucose

9. Glycolysis: Net Energy Yield
Input
Glucose
2 NAD+
2ATP (energy requiring)
4ADP
Output
2 pyruvate
2 NADH (electron carrier)
2ADP
4 ATP
(energy releasing)
(net gain of 2 ATP)

11. Krebs Cycle (Citric Acid Cycle) - video
Chapter 8
Cellular Energy
Krebs Cycle (Citric Acid Cycle) - video
Also known as Citric Acid Cycle
Occurs when oxygen is present
Occurs in the mitochondria
Pyruvate is further broken down
The net yield from the Krebs cycle is:
6 CO2 molecules (we exhale)
2 ATP
8 NADH (important electron carrier)
2 FADH2 (important electron carrier)

13. Krebb Cycle: Net Energy Yield
Input
Pyruvate (3 carbon sugar)
8 NAD+
2 FAD
2 ADP
Output
6 CO2
8 NADH (electron carrier)
2 FADH2 (electron carrier)
2ATP

14. Electron Transport Chain
Occurs in the mitochondria
Requires the presence of oxygen
will combine with the H ions to form water
Final step in the breakdown of glucose
Uses the NADH and FADH2 to convert ADP to ATP
Produces 32 ATP

15. Electron Transfer Chain
Electron Transport Chain
OUTER COMPARTMENT H+ H+ H+ H+ H+ H+ H+ H+ H+ H+ H+ H+ H+ H+ H+ H+ H+ H+ H+ H+ e- e- e- H+ H+ H+
ADP + Pi
ATP
NADH + H+
NAD+ + 2H+
FADH2
FAD + 2H+
2H+ + 1/2 02
H2O
Electron Transfer Chain
ATP Synthase H+
INNER COMPARTMENT

16. Electron Transport Chain
glucose
Electron Transport Chain
ATP
2 PGAL
ATP
2 NADH
2 pyruvate
glycolysis
2 FADH2
2 CO2 e–
2 acetyl-CoA
2 NADH H+ H+ 2
6 NADH
KREBS
CYCLE
ATP
Krebs
Cycle
ATP H+
2 FADH2
ATP H+
4 CO2 36
ATP H+ H+
ADP + Pi
electron
transfer
chain H+ H+ H+

17. Electron Transport: Net Energy Yield
Input
8 NADH (from krebs cycle)
2 FADH2 (from krebs cycle)
Oxygen
Output
8 NAD+
2 FAD+
Water
32 ATP

18. ATP Production (per molecule of glucose)
Glycolysis ____ATP
Kreb Cycle ____ATP
ETC ____ATP
Total ____ATP

20. Linked Processes Photosynthesis Aerobic Respiration
Energy-storing pathway
Dehydration synthesis
Anabolic reaction
bonds are formed
endothermic
Releases oxygen
Requires carbon dioxide
Aerobic Respiration
Energy-releasing pathway
Hydrolysis reaction
Catabolic reaction
bonds are broken
exothermic
Releases carbon dioxide
Requires oxygen
Metabolism (Metabolic Rate) = Catabolic rate + Anabolic rate

21. Anaerobic Respiration
Chapter 8
Cellular Energy
Anaerobic Respiration
The anaerobic pathway that follows glycolysis
No oxygen is required
Two main types
Lactic acid fermentation
Alcohol fermentation

22. Lactic Acid Fermentation
Occurs in the cytoplasm
Occurs during exercise when there isn’t enough oxygen present for respiration to occur
Cells turn to fermentation to produce energy
only a net of 2 ATP
another product of the reaction is lactic acid
inhibits muscle function
causes muscles to become fatigued
causes cramps
causes soreness after exercise

23. Lactic Acid Fermentation

24. Lactic Acid Fermentation
Lactic acid is used by microorganisms to produce food, such as
yogurt
cheese
pickled foods
even chocolate

25. Alcohol Fermentation Occurs with yeast, no oxygen present
carbon dioxide causes bread to rise

26. Alcohol Fermentation
Yeast’s ferment the carbohydrates in fruits and grains
This process forms ethanol
Source of bubbles in
Beer
Sparkling wines

28. Which statement describes the law of conservation of energy?
Chapter 8
Cellular Energy
Which statement describes the law of
conservation of energy?
Energy cannot be converted or destroyed.
Energy can be converted and destroyed.
Energy can be converted but not destroyed.
Energy can be destroyed but not converted. A B C D
CDQ 1

29. In which metabolic process are molecules
Chapter 8
Cellular Energy
In which metabolic process are molecules
broken down to produce carbon dioxide and
water?
photosynthesis
cellular respiration
homeostasis
fermentation A B C D
CDQ 2

30. At the end of the Calvin cycle, where is energy stored?
Chapter 8
Cellular Energy
At the end of the Calvin cycle, where is energy
stored?
NADPH
ATP
chloroplast
glucose A B C D
CDQ 3

31. Chapter 8
Cellular Energy
Which law of thermodynamics explains why the ladybug receives the least amount of usable energy? A B
the first law of thermodynamics
the second law of thermodynamics
FQ 1

32. All of the energy from the food you eat comes from the sun.
Chapter 8
Cellular Energy
All of the energy from the food you eat comes from the sun.
true
false A B
FQ 2

33. Why is cellular respiration a catabolic pathway?
Chapter 8
Cellular Energy
Why is cellular respiration a catabolic pathway?
Energy is used to form glucose and oxygen.
Energy is converted from water to carbon dioxide.
Energy that is lost is converted to thermal energy.
Energy is released by the breakdown of molecules. A B C D
FQ 3

34. Why is adenosine triphosphate (ATP) such an
Chapter 8
Cellular Energy
Why is adenosine triphosphate (ATP) such an
important biological molecule?
It captures light energy from the sun.
It is produced in anabolic pathways.
It stores and releases chemical energy.
It converts mechanical energy to thermal energy. A B C D
FQ 4

35. Where in the plant cell does photosynthesis take place?
Chapter 8
Cellular Energy
Where in the plant cell does photosynthesis take place?
chloroplasts
Golgi apparatus
mitochondria
vacuoles A B C D
FQ 5

36. Which range of wavelengths is reflected by chlorophylls a and b?
Chapter 8
Cellular Energy
Which range of wavelengths is reflected by chlorophylls a and b? nm nm nm A B C
FQ 6

37. Which mechanism of photosynthesis uses
Chapter 8
Cellular Energy
Which mechanism of photosynthesis uses
the movement of hydrogen ions (H+) across
a concentration gradient to synthesize ATP?
absorption
chemiosmosis
electron transport
C2 pathway A B C D
FQ 7

38. What is the overall purpose of cellular respiration?
Chapter 8
Cellular Energy
What is the overall purpose of cellular
respiration?
to make ATP
to process H2O
to store glucose
to deliver oxygen A B C D
FQ 9

39. Which represents the general sequence of cellular respiration?
Chapter 8
Cellular Energy
Which represents the general sequence of
cellular respiration?
TCA cycle  chemiosmosis  glycolysis
glycolysis  Krebs cycle  electron transport
electron absorption  catalysis  phosphorylation
aerobic pathway  anaerobic pathway  fermentation A B C D
FQ 10

40. Which stage of cellular respiration is the anaerobic process?
Chapter 8
Cellular Energy
Which stage of cellular respiration is the
anaerobic process?
glycolysis
Krebs cycle
electron transport A B C
FQ 11

41. CoA CO2 FADH2 NADH Which molecule generated by the Krebs
Chapter 8
Cellular Energy
Which molecule generated by the Krebs
cycle is a waste product?
CoA
CO2
FADH2
NADH A B C D
FQ 12

42. Chapter 8
Cellular Energy
Look at the following figure. Which part of the chloroplast is a sac-like membrane arranged in stacks?
grana
stroma
thylakoids
Golgi apparatus A B C D
CAQ 1

43. During the Krebs cycle, pyruvate is broken down into what compound?
Chapter 8
Cellular Energy
During the Krebs cycle, pyruvate is broken down into what compound?
H2O O2 CO
CO2 A B C D
CAQ 2

44. Chapter 8
Cellular Energy
Chapter Assessment Questions
Look at the following figure. Which molecule is released when ATP becomes ADP?
phosphate group
water molecule
ribose sugar
energy cells A B C D
CAQ 3

45. A B Which metabolic process is photosynthesis? A B Chapter 8
Cellular Energy
Which metabolic process is photosynthesis? A B A B
STP 1

46. At the beginning of photosynthesis, which
Chapter 8
Cellular Energy
At the beginning of photosynthesis, which
molecule is split to produce oxygen (O2) as
a waste product?
CO2
H2O
C6H12O6
3-PGA A B C D
STP 2

47. What is the final step of cellular respiration?
Chapter 8
Cellular Energy
What is the final step of cellular respiration?
O2 and H+ form H2O.
Electrons and H2O generate ATP.
C6H12O6 is broken down into CO2.
NADH and FADH2 gain electrons. A B C D
STP 5

48. an increased demand for ATP
Chapter 8
Cellular Energy
What prevents pyruvate from entering the Krebs cycle and instead results in this pathway?
a buildup of CO2
a lack of oxygen
an excess of glucose
an increased demand for ATP A B C D
STP 6