1. Warm-Up #9 12/4/12 1) What are the 3 external plant layers? 2) Why are the top two layers clear? 3) What is the purpose of a stomata? 4) What controls the opening of stomata? 5) What layer are the stomata located?

2. Leaf Structure Unit 5 Metabolism

3. Today is About… Essential Question: Essential Question: What happens when leaves change color and fall to the ground? What happens when leaves change color and fall to the ground? Objective Objective Diagram the structure of a leaf

4. Photosynthesis Occurs in the chloroplast of the leaves Occurs in the chloroplast of the leaves Leaf is thin Leaf is thin Very large surface area (ideal for diffusion/absorption). The larger the surface area the more sunlight can be absorbed. Very large surface area (ideal for diffusion/absorption). The larger the surface area the more sunlight can be absorbed. Mesophyll cells are closer to the surface \ Mesophyll cells are closer to the surface \ reducing diffusion distance of CO 2 from surrounding mesophyll cells reducing diffusion distance of CO 2 from surrounding mesophyll cells

5. External Features Waxy Cuticle Waxy Cuticle Top of leaf Top of leaf Transparent Transparent Allows light to enter for photosynthesis Allows light to enter for photosynthesis Upper epidermal cells Upper epidermal cells Transparent Transparent Allow light in to reach the chloroplast Allow light in to reach the chloroplast Lower epidermis Lower epidermis Has stomata, which allows gas exchange (intake of CO 2 and release of O 2 ) Has stomata, which allows gas exchange (intake of CO 2 and release of O 2 )

6. Stomata Openings in the leaf Openings in the leaf Controlled by doors called guard cells Controlled by doors called guard cells Permit exchange of moisture and carbon dioxide between leaf and atmosphere Permit exchange of moisture and carbon dioxide between leaf and atmosphere

8. Internal Features Vascular Tissue- found in leaf vein Vascular Tissue- found in leaf vein Xylem Xylem Top of leaf Top of leaf Transports water to leaf cells and then it diffuses into chloroplast. Transports water to leaf cells and then it diffuses into chloroplast. Phloem Phloem Bottom of leaf Bottom of leaf Transports food from mesophyll to rest of plant Transports food from mesophyll to rest of plant

9. Mesophyll- two main types Mesophyll- two main types Palisade Palisade Contain the most chloroplast Contain the most chloroplast Found at top of leaf Found at top of leaf Closely packed with small spaces in between to allow gas exchange Closely packed with small spaces in between to allow gas exchange Spongy Spongy Less chloroplast Less chloroplast Larger open spaces Larger open spaces Store carbohydrates made by photosynthesis Store carbohydrates made by photosynthesis Internal Features Cont.

10. Chloroplast Chloroplast Contain chlorophyll (WHERE PHOTOSYNTHESIS TAKES PLACE) Contain chlorophyll (WHERE PHOTOSYNTHESIS TAKES PLACE) Double membrane that is selectively permeable Double membrane that is selectively permeable Allows H 2 O and CO 2 to diffuse into it and O 2 to diffuse out Allows H 2 O and CO 2 to diffuse into it and O 2 to diffuse out Parenchyma Parenchyma Rich in chloroplast Rich in chloroplast Primary site of photosynthesis in the leaf Primary site of photosynthesis in the leaf

11. Internal Features Cont… Guard Cells Guard Cells Controls the opening and closing of the stomata Controls the opening and closing of the stomata http://academic.kellogg.edu/herbrandsonc/bio111/animations/0021.swf

13. Warm- Up #8 12/3/12 1) What part of the plant are most chloroplast found in? 2) How is energy stored during photosynthesis 3) How is energy released during photosynthesis? 4) What is the product of the light dependent reaction? 5) What is the product of the light independent reaction?