1. Photosynthesis

2. Anatomy of a leaf
If you cut a leaf down the middle and look at it from the edge[ which is the cross section] you will observe several different types of cells

4. The top half of the leaf is covered with a waxy cuticle layer that prevents evaporation of water
Beneath the cuticle are the tall palisade layers
This is where the plant cells are found

5. Photosynthesis happens in the “palisade” cells in the leaf:

6. Close up on a palisade cell:
Cell wall
Cell membrane
Chloroplasts (containing chlorophyll)
Large vacuole
Nucleus
Cytoplasm

7. The underside of the leaf has openings called stomates
The stomates allow gases to move in and out of the leaf
Stomates have the same function as the cell membrane

8. Each stomate is surrounded by 2 guard cells
The guard cells can open or close the stomate to control water loss

10. Most plants have their stomates open during the day when photosynthesis is occurring
Every evening the stomates close

11. The main function of the guard cells and stomates is to maintain homeostasis by controlling water loss

12. TRANSPIRATION is the loss of water vapor into the atmosphere through the stomates of leaves

13. The leaf also has veins which contain Xylem and Phloem

14. Xylem tissue is a system of tubes that carry water and minerals from the soil up to the leaves
Phloem tissue is composed of tubes that transport materials throughout the plant

16. TEST QUESTION 
50. State one way transpiration is beneficial to plants.
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17. 51. Identify two of the “vital gases” that are exchanged between leaf tissues and the outside environment. ________________________________ and __________________________________ 52. Identify the specific leaf structures that regulate the opening and closing of stomates. ___________________________________

18. Plants are autotrophs; they’re able to make their own food

19. How do plants make their own food?
Through the process of photosynthesis

20. Process of photosynthesis
The process by which green plants converts light energy to chemical energy
1.Leaves absorb water
2.Leaves also absorb carbon dioxide

21. 3. Leaves use light from the sun to turn the carbon dioxide and water into glucose and oxygen
4. The chemical reaction of photosynthesis occurs within chloroplasts found in leaves

22. The Photosynthesis Equation

25. What are the basic raw MATERIALS of photosynthesis
What are the end products of photosynthesis?
What’s the energy source for photosynthesis?

26. Why is photosynthesis important?
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27. What are Pigments?
Pigments: Light-absorbing colored molecules that are found in the chloroplast
Chlorophyll is the pigment that’s located in the chloroplast

28. Chlorophyll is made up of several pigments:
1. chlorophyll A gives plants its dark green color
2. chlorophyll B  light green color in plants

29. 3.Carotenes gives plants its orange color
4. xanthophylls gives plants its yellow color

30. The main function of the carotenes and xanthophylls is photoprotection
They absorb excessive sunlight energy that would damage chlorophyll a and b

31. 5. Anthocyanins gives leaves their red color
This chlorophyll prevents damage to leaves from intense sunlight energy
They also produce a bad tasting chemical which makes the leaves appear as a toxin so that herbivores won’t eat it

33. Why do leaves turn yellow, orange, and red during the fall?
When the temperature gets cool, plants stop making chlorophyll A & B

34. Inside A Chloroplast

35. Structure of the Chloroplast
Thylakoids: each of a number of flattened sacs inside a chloroplast

36. Granun: a stack of Thylakoids
Stroma: Gel-like material inside the chloroplast

37. Photosynthesis is divided into 2 phases

38. Phase 1: light dependent reactions
1. Water molecules are split[photolysis]
2. Oxygen is released
3. The sunlight is used to make 2 molecules: ATP and NADPH
The light reactions occurs in the thylakoids of the chloroplast

39. Phase 2: [Calvin Cycle] [dark reactions]
4.Carbon Dioxide + ATP + NADPH makes one molecule of glucose (G3P)
The Calvin Cycle occurs in the stroma of the Chloroplast

40. Then, the plants use the sugars formed during the Calvin cycle as:
a source of energy for animals that eat plants
a substance to make cellulose
Energy source for plant growth

41. The Calvin Cycle

43. Factors Affecting the Rate of Photosynthesis
1.Temperature
When the temperature is higher than 35°C,the rate of photosynthesis decreases

44. 2. Light Intensity
As sunlight increases, the rate of photosynthesis increases until a certain point

45. 3. CO2 concentration
If there’s an increase in CO2 concentration, then the rate of photosynthesis increases

46. 4. water
a shortage of water slows down photosynthesis
5. minerals
If a mineral is missing from the soil, it causes a negative effect on the entire process of photosynthesis