Warm-Up #9 12/4/12Warm-Up #9 12/4/12

1) What are the 3 external plant layers?1) What are the 3 external plant layers?

2) Why are the top two layers clear?2) Why are the top two layers clear?

3) What is the purpose of a stomata?3) What is the purpose of a stomata?

4) What controls the opening of stomata?4) What controls the opening of stomata?

5) What layer are the stomata located?5) What layer are the stomata located?

Leaf StructureLeaf Structure

Unit 5Unit 5

MetabolismMetabolism

Today is About…Today is About…

Essential Question:Essential Question: What happens when What happens when

leaves change color and leaves change color and fall to the ground?fall to the ground?

ObjectiveObjective Diagram the structure Diagram the structure

of a leafof a leaf

PhotosynthesisPhotosynthesis

Occurs in the chloroplast of the leavesOccurs in the chloroplast of the leaves Leaf is thin Leaf is thin Very large surface area (ideal for Very large surface area (ideal for

diffusion/absorption). The larger the surface area diffusion/absorption). The larger the surface area the more sunlight can be absorbed.the more sunlight can be absorbed.

Mesophyll cells are closer to the surface \Mesophyll cells are closer to the surface \ reducing diffusion distance of COreducing diffusion distance of CO22 from surrounding from surrounding

mesophyll cellsmesophyll cells

External FeaturesExternal Features Waxy CuticleWaxy Cuticle

Top of leafTop of leaf TransparentTransparent Allows light to enter for Allows light to enter for

photosynthesisphotosynthesis Upper epidermal cellsUpper epidermal cells

TransparentTransparent Allow light in to reach Allow light in to reach

the chloroplastthe chloroplast Lower epidermisLower epidermis

Has stomata, which Has stomata, which allows gas exchange allows gas exchange (intake of CO(intake of CO2 2 and and release of Orelease of O22))

StomataStomata Openings in the leafOpenings in the leaf Controlled by doors called guard cellsControlled by doors called guard cells Permit exchange of moisture and carbon Permit exchange of moisture and carbon

dioxide between leaf and atmospheredioxide between leaf and atmosphere

Internal FeaturesInternal Features Vascular Tissue- found in leaf veinVascular Tissue- found in leaf vein

XylemXylem Top of leafTop of leaf Transports water to leaf cells and then it diffuses into Transports water to leaf cells and then it diffuses into

chloroplast.chloroplast. PhloemPhloem

Bottom of leafBottom of leaf Transports food from mesophyll to rest of plantTransports food from mesophyll to rest of plant

Mesophyll- two main typesMesophyll- two main types PalisadePalisade

Contain the most chloroplastContain the most chloroplast Found at top of leafFound at top of leaf Closely packed with small Closely packed with small

spaces in between to allow spaces in between to allow gas exchangegas exchange

SpongySpongy Less chloroplastLess chloroplast Larger open spacesLarger open spaces Store carbohydrates made by Store carbohydrates made by

photosynthesis photosynthesis

Internal Features Cont.Internal Features Cont.

Internal Features Cont.Internal Features Cont. ChloroplastChloroplast

Contain chlorophyll (WHERE Contain chlorophyll (WHERE PHOTOSYNTHESIS TAKES PHOTOSYNTHESIS TAKES PLACE)PLACE)

Double membrane that is Double membrane that is selectively permeableselectively permeable

Allows HAllows H22O and COO and CO22 to diffuse to diffuse into it and Ointo it and O2 2 to diffuse outto diffuse out

ParenchymaParenchyma Rich in chloroplastRich in chloroplast Primary site of photosynthesis in Primary site of photosynthesis in

the leafthe leaf

Internal Features Cont…Internal Features Cont…

Guard CellsGuard Cells Controls the opening and Controls the opening and

closing of the stomataclosing of the stomata

http://academic.kellogg.edu/herbrandsonc/bio111/animations/0021.swf

Warm- Up #8 12/3/12Warm- Up #8 12/3/12

1)1) What part of the plant are most chloroplast found What part of the plant are most chloroplast found in?in?

2)2) How is energy stored during photosynthesisHow is energy stored during photosynthesis

3)3) How is energy released during photosynthesis?How is energy released during photosynthesis?

4)4) What is the product of the light dependent reaction?What is the product of the light dependent reaction?

5)5) What is the product of the light independent What is the product of the light independent reaction?reaction?