Agenda 11/30- Photosynthesis Bellwork- discuss homework Cellular Respiration Cartoon New Information: Photosynthesis and Plant Cell Specialization HW- photosynthesis starts with … 152985921 152985921

Some types of bacteria are able to perform photosynthesis Some types of bacteria are able to perform photosynthesis. These bacteria must therefore contain which of the following in their membranes? A. chlorophyll B. glucose C. mitochondria D. ribosomes What is the primary role of photosynthesis in the carbon cycle? A. releasing carbon to the oceans B. removing carbon from the atmosphere C. transferring carbon from the soil to organisms D. transferring carbon from producers to decomposers

Agenda 12/01/15- Photosynthesis Bellwork New Information- Photosynthesis Activity- Photosynthesis starts with … Review for test tomorrow

Photosynthesis Video As you watch, consider the following: Where does the energy that drives photosynthesis come from? What molecules are formed during photosynthesis? What 2 molecules carry energy that is eventually stored in glucose? What kinds of organisms contain chloroplasts?

THE BASICS OF PHOTOSYNTHESIS Most plants are photosynthetic autotrophs, as are some bacteria and protists Autotrophs: make their own food through photosynthesis Sunlight energy is transformed into chemical energy stored in chemical bonds (c) Euglena (b) Kelp (d) Cyanobacteria (a) Mosses, ferns, and flowering plants 5

Light Energy Harvested by Photosynthetic Autotrophs 6 CO2 + 6 H2O + light energy → C6H12O6 + 6 O2 6

Food Chain 7

The location and structure of chloroplasts LEAF CROSS SECTION MESOPHYLL CELL LEAF Mesophyll CHLOROPLAST Intermembrane space Outer membrane Granum Inner membrane Grana Stroma Thylakoid compartment Stroma Thylakoid 8

Chloroplasts Intermembrane space Outer membrane Thylakoid Inner membrane Granum Stroma

A Chloroplast Light Energy Grana (stacks of thylakoids) Chemical H2O O2 Sugars CO2 Chloroplast NADP+ ADP Light- Dependent Reactions Calvin Cycle Grana (stacks of thylakoids) ATP NADPH Chemical Energy

2 Pathways of Photosynthesis Light-dependent reactions Light energy absorbed Occurs across thylakoid membranes Produces ATP and NADPH (and O2) Light-independent reactions or Calvin Cycle Does not require light energy Occurs in the stroma Produces glucose using CO2

ATP ATP - Adenosine Triphosphate Adenine Ribose 3 Phosphate groups

Formation of ATP ATP stores enough energy for many cellular functions. ADP ATP Adenosine triphosphate (ATP) Energy Adenosine diphosphate (ADP) + Phosphate Partially charged battery Fully charged battery ATP stores enough energy for many cellular functions.

H2O CO2 C6H12O6 O2 Sunlight Energy NADP+ ADP ATP NADPH Light Independent Reactions in the Stroma Light Dependent Reactions in the Thylakoids ATP NADPH C6H12O6 O2

Light Dependent Reactions Pigments arranged into photosystems Photosystem I (happens 2nd) Photosystem II (happens 1st) Inputs: H2O Light Energy ADP, NADP+ Products: ATP, NADPH (go on to fuel the Calvin Cycle) O2

Light Dependent Reactions Electron transport chain Produces energy for ATP production ATP Synthase (enzyme) binds ADP and a phosphate group into ATP

H2O CO2 C6H12O6 O2 Sunlight Energy NADP+ ADP ATP NADPH Stroma Thylakoids ATP NADPH C6H12O6 O2

Light-Independent Reactions, aka Calvin Cycle occurs in stroma uses ATP and NADPH from the light-dependent reactions and CO2 to make glucose (C6H12O6)

The Calvin Cycle Inputs: ATP NADPH CO2 Products: C6H12O6 ADP NADP+ CO2 Enters the Cycle Energy Input Inputs: ATP NADPH CO2 Products: C6H12O6 ADP NADP+ 5-Carbon Molecules Regenerated Sugars and other compounds 6-Carbon Sugar Produced

H2O CO2 C6H12O6 O2 Sunlight Energy NADP+ ADP ATP NADPH Stroma Thylakoids ATP NADPH C6H12O6 O2 20

Why Are Plants Green? Electromagnetic Spectrum and Visible Light Gamma rays Infrared & Microwaves X-rays UV Radio waves Visible light Wavelength (nm)

WHY ARE PLANTS GREEN? Different wavelengths of visible light are seen by the human eye as different colors. Gamma rays Micro- waves Radio waves X-rays UV Infrared Visible light Wavelength (nm)

Properties of Light Plant pigments absorb light energy. be reflected when a photon (unit of light) strikes a substance, it may be reflected be absorbed be transmitted Plant pigments absorb light energy. This fuels the production of ATP, NADPH

Why are plants green? Reflected light Because they reflect green light

The color of light seen is the color REFLECTED, NOT ABSORBED Chloroplasts have pigments that absorb light energy and convert it to chemical energy What colors of light does chlorophyll absorb? Reflect? Reflected light Light Absorbed light Transmitted light Chloroplast

Why do plants have pigments other than chlorophyll? Green to Greenish-yellow Yellow/Orange/Red

Different pigments absorb light differently Green to Greenish-yellow Yellow/Orange/Red

Chloroplast Pigments Thylakoids in chloroplasts contain several pigments Chlorophyll a (bright green) Chlorophyll b (yellow-green) Carotenoids (yellow/orange) Xanthophylls (yellow) Anthocyanins (red) Figure 7.7

Why do plants have pigments other than chlorophyll? To absorb more energy from wavelengths (colors) of light that chlorophyll does not absorb. This allows them to make more food!

Concept Map Photosynthesis Light- dependent reactions Calvin cycle Section 8-3 Photosynthesis includes Light- dependent reactions Calvin cycle takes place in uses use take place in Energy from sunlight Thylakoid membranes Stroma ATP NADPH to produce of to produce High-energy sugars ATP NADPH O2 Chloroplasts Go to Section:

Endosymbiotic Theory (Lynn Margulis, 1981) Mitochondria and chloroplasts may have originated as free-living prokaryotes that lived symbiotically within cells, leading to eukaryotes. Evidence: Circular DNA Reproduction Two or more cell membranes Ribosomes animation

Compare/Contrast Photosynthesis Cellular Respiration Energy Storing or Releasing Energy storing Energy releasing Products Glucose, oxygen gas Carbon dioxide, water, energy (ATP) Reactants Carbon dioxide, water, light energy Location Chloroplast Mitochondrion