1. Chapter 9
Energy In a Cell

2. All living organisms must be able to obtain energy from their environment
Most cell functions require ATP.
Examples:
Making proteins or synthesizing other macromolecules
Essential for maintaining homeostasis by moving molecules through the membrane by active transport
Rid the cell of toxins by exocytosis
Find and engulf food by endocytosis
Movement to avoid danger

3. ATP
Adenosine Triphosphate or ATP is an energy storing molecule that provides direct energy to your cells
ATP = ENERGY!
ATP is composed of an adenosine molecule with 3 phosphate groups attached
ATP releases energy quickly whenever a cell needs it.

4. ATP
ADENOSINE P P P
3 Phosphate Groups

5. ATP The phosphate groups are positively charged and repel each other
It takes energy to hold them together
When the bond breaks, energy is released
Like a spring being released

6. P
ADENOSINE P P
Energy

7. ADP
When one phosphate group breaks away, ATP becomes Adenosine Diphosphate (ADP)
ADP has only two phosphate groups and holds less energy than ATP

8. ADP
ADENOSINE P P
2 Phosphate Groups

9. AMP
Adenosine Monophosphate (AMP) has only one phosphate and holds the least energy

10. AMP
ADENOSINE P
1 Phosphate Group

11. ATP  ADP  ATP
ATP and ADP are made and broken down in a cycle
ATP
Energy P
ADP

12. ADENOSINE
ATP P P P
Energy
ADENOSINE P P
ADP P
ADENOSINE P P P
ATP

13. 9.2 - Photosynthesis

14. Photosynthesis
Photosynthesis is the process that uses the sun’s energy to make glucose (simple sugar)

15. Why is Photosynthesis important?
Makes organic molecules (glucose) out of inorganic materials (carbon dioxide and water).
It begins all food chains/webs. Thus all life is supported by this process.
It also makes oxygen gas!!

16. Photosynthesis-starts all ecological food webs!

18. Chloroplast
Chloroplast is the cell organelle where photosynthesis occurs
Chloroplast contains a pigment called CHLOROPHYLL
Pigment: a molecule that absorbs light
Chlorophyll absorbs all wavelengths of light except green. Green is reflected back; plants look green because green is reflected back

19. (Dark Reactions)
(Light Reactions)

20. Photosynthesis
What happens in the fall when deciduous trees loose their leaves?
Chlorophyll stops being made.
Other pigments show up before the leaf is dropped.

21. Photosynthesis Equation
SUN
6 CO2
6 H2O
C6H12O6
6 O2
(GLUCOSE)

22. Glucose Glucose stores energy Glucose can be broken down to make ATP
Glucose is also used by the plant to make starch and cellulose

23. 9.3 – Cellular Respiration
Getting Energy to Make ATP

24. Cellular Respiration ATP
The process by which organisms break down food molecules (glucose) to produce ATP
ATP
Cellular Respiration
Glucose

25. Two Types of Respiration
There are two basic types of cellular respiration
AEROBIC respiration: requires oxygen
ANAEROBIC respiration: no oxygen O2 O2

26. Formula for aerobic respiration
SUN
6CO2 + 6H2O → C6H12O6 + O2
(Glucose)
C6H12O6 + O2 → 6CO2 + 6H2O + ATP
(energy)

27. Mitochondria
The mitochondria is the organelle where aerobic respiration takes place

28. Aerobic Respiration There are 3 stages of aerobic respiration
1. Glycolysis
2. The Citric Acid (Krebs) Cycle
3. The Electron Transport Chain O2 O2 O2

29. 3 Stages of Aerobic Respiration
Stage 1 - Glycolysis (Lysis = split) Glucose splits into 2 molecules. Occurs in the cytoplasm (anaerobic) ATP: 2 gets used, 4 are created NET GAIN = 2 ATP

30. 3 Stages of Aerobic Respiration
Stage 2 – Citric Acid Cycle Occurs in the mitochondria Chemical reactions that produce CO2 ATP: 2 are created

31. 3 Stages of Aerobic Respiration
Stage 3 – Electron Transport Chain Occurs in the mitochondria Uses molecules from Citric Acid Cycle to make ATP. H2O is released. ATP: 32 created

32. Aerobic Respiration
Total ATP made from one Glucose molecule: 38 ATP But, 2 ATP are used in Glycolysis, SO, 36 ATP is the total useable ATP .

34. Total ATP Production
Overall, aerobic respiration produces a total of 36 molecules of ATP
Glycolysis net ATP
Citric Acid Cycle ATP
Electron Transport Chain ATP
Total ATP Produced ATP

35. Equation for Aerobic Respiration
C6H12O6
6 CO2
6 H2O
6 O2
(GLUCOSE)
36 ATP

36. If Oxygen is not present…
Anaerobic Respiration occurs in the cell.
an - without
aerobic – oxygen
Sometimes cells are without O2.
Gylcolysis still happens, then fermentation.

37. Anaerobic Respiration
Respiration WITHOUT oxygen is called anaerobic respiration
Anaerobic respiration is also called FERMENTATION
There are two types of fermentation
Lactic acid fermentation
Alcoholic fermentation

38. Lactic Acid Fermentation
Lactic acid fermentation occurs in mammals during exercise when cells run out of oxygen
Occurs in the cytoplasm
Lactic acid fermentation only creates 2 ATP
Inefficient compared to aerobic respiration
Lactic acid is released as a byproduct which builds up causing a burning sensation in your muscles during strenuous exercise and causes sore muscles after exercising

39. Equation for Lactic Acid Fermentation
C6H12O6
Lactic Acid
(GLUCOSE)
2 ATP

40. Alcoholic Fermentation
Alcoholic fermentation occurs in yeast/bacteria in the absence of oxygen
Alcoholic fermentation creates 2 ATP
Inefficient compared to aerobic respiration
Alcoholic fermentation releases CO2 and alcohol as byproducts
Yeast is used to make beer and bread

41. Alcohol Equation for Alcoholic Fermentation C6H12O6 CO2 (GLUCOSE)
2 ATP

42. Photosynthesis Equation
6 CO2
6 H2O
C6H12O6
6 O2
Sunlight
(GLUCOSE)
Aerobic Respiration Equation
C6H12O6
6 CO2
6 H2O
6 O2
ATP
(GLUCOSE)

43. Cellular Energy Comparison
Photosynthesis
Aerobic Cellular Respiration
Glucose made.
Energy from sun is stored in glucose.
CO2 taken in.
O2 given off.
Glucose is produced.
Need Sunlight & chlorophyll.
Occurs in Chloroplast.
Only in photosynthetic organisms.
Write the equation!
Glucose broken down/used.
Energy from glucose is released.
CO2 given off.
O2 taken in.
CO2 & H2O produced.
Needs glucose & O2.
Occurs in Mitochondria.
Happens in all living cells.
Write the equation!