1. Photosynthesis
SBI 3C

2. Overview All energy on earth comes from the sun. We depend on: Plants
Algae (underwater plants)
Cyanobacteria (photosynthetic bacteria)
To provide this energy to us!

3. Cells usable source of energy is called ATP
Cell Energy:
Cells usable source of energy is called ATP
ATP stands for adenosine triphosphate
Adenine
Ribose
3 Phosphate groups
It is a molecule that transfer energy from broken down food molecules.

5. Photosynthesis:
Photosynthesis is the process by which the energy of sunlight is converted into the energy of glucose

6. Photosynthesis occurs in the chloroplasts of plants

7. Chlorophyll is the pigment inside the chloroplast the absorbs light for photosynthesis
As the chlorophyll in leaves decays in the autumn, the green color fades and is replaced by the oranges and reds of carotenoids.

8. Overall Reaction What is the equation for photosynthesis?
carbon dioxide + water  glucose + oxygen + energy
6CO H2O  C6H12O O2 + energy
Reactants
Products

9. Chloroplasts Have TWO membranes
A “bi-bilayer!”
The inner membrane is called the thylakoid.
The thylakoid is folded and looks like stacks of coins called granum (grana singular).
The stroma is the Fluid surrounding the granum
Need the granum and stroma for photosynthesis
Image source:

10. Light (dependent)Reactions
Happen ONLY in sunlight (depend on light)
Chlorophyll absorbs energy from sunlight. The energy is transferred along the thylakoid membrane, where water molecules are broken down and oxygen molecules are release.
Energy carrying molecules (ATP) transfer energy
Image from: Biology 11: College Preparation. Pg 74. Nelson, Toronto

11. Light Independent Reactions (formerly the “dark reactions”)
Use energy from the light-dependent reactions to make sugar.
3. Carbon dioxide molecules are used to build sugars.
4. 6-carbon sugar (glucose or fructose) are produced. Used to build to build starches and cellulose.
Calvin Cycle—energy is transferred from ATP and NADPH to the organic compound glucose
Image from: Biology 11: College Preparation. Pg 74. Nelson, Toronto

12. Cellular Respiration: (2 kinds—Aerobic and Anaerobic)
Cellular respiration is the process by which the energy of glucose is released in the cell to be used for life processes (movement, breathing, blood circulation, etc…)

13. Cells require a constant source of energy for life processes but keep only a small amount of ATP on hand. Cells can regenerate ATP as needed by using the energy stored in foods like glucose.
The energy stored in glucose by photosynthesis is released by cellular respiration and repackaged into the energy of ATP.

14. Respiration occurs in ALL cells and can take place either with or without oxygen present.

15. Aerobic Respiration: requires oxygen
Occurs in the mitochondria of the cell
Up to 38 ATP molecules produced
General formula for aerobic respiration:
C6H12O O CO H2O + 38 ATP
glucose + oxygen carbon dioxide + water + energy
Human cells contain a specialized structure – the mitochondrion – that generates energy.

16. Summary:
3 steps:
1st glycolysis
2nd Krebs cycle
3rd Electron
Transport
Chain (ETC)

17. Electron Transport Chain
Diagram
Electrons carried in NADH
Mitochondria
Electrons carried in NADH and FADH2
In Cytoplasm
Krebs Cycle
Glucose
Electron Transport Chain
Glycolysis 2 2 38

18. Anaerobic Respiration: occurs when no oxygen is available to the cell (2 kinds: Alcoholic and Lactic Acid)
Also called fermentation
Much less ATP produced than in aerobic respiration

19. Alcoholic fermentation—occurs in bacteria and yeast
Process used in the baking and brewing industry—yeast produces CO2 gas during fermentation to make dough rise and give bread its holes
glucose ethyl alcohol + carbon dioxide + 2 ATP

20. Lactic acid fermentation—occurs in muscle cells
Lactic acid is produced in the muscles during rapid exercise when the body cannot supply enough oxygen to the tissues—causes burning sensation in muscles
glucose lactic acid + carbon dioxide + 2 ATP

22. Differences between photosynthesis and respiration