REACTIONS of PHOTOSYNTHESIS http://vilenski.org/science/safari/cellstructure/chloroplasts.html REACTIONS of PHOTOSYNTHESIS http://www.science.siu.edu/plant-biology/PLB117/JPEGs%20CD/0076.JPG

Law of Thermodynamics *energy cannot be created nor destroyed BUT it can change forms. Photosynthesis converts solar energy into chemical energy.

Who and Where? Photosynthesis occurs in the chloroplast. All organisms with chloroplasts can conduct photosynthesis.

Chemical Equation Raw Materials Products CO2 – from animals C6H12O6 – glucose/food H2O – water absorbed O2 – oxygen gas used by Chlorophyll –plant pigment animals

Reactions of Photosynthesis There are two reactions involved: Light Reactions – * Must have light. * Purpose – to capture light energy. Dark Reactions – * Don’t need light. * Purpose – to make glucose.

Light Energy colors Visible light is made up of many different _______________of light Your eyes “see” different sizes of waves as different ___________ wavelengths colors http://www.simontucket.com/_Portfolio/PortLarge/L_Il_Prism.jpg

Myth: Many people think that plants are green because they absorb and use green light in photosynthesis, BUT . . . . Image from: http://oogletutorials.com/wp-content/uploads/2007/12/photoshop-lesson-green-leaf-design26.gif

BUT… We “see” reflected light Light wavelengths that are ___________ off of objects bounce back to our eyes . That is the ___________ we “see” REFLECTED COLOR Image modified from: http://www.visibledreams.net/Web/color/color_3.html

absorbs ALL except BLUE reflected This book “looks BLUE” because the dye in this cover _______________ of the wavelengths of light _________ blue. _______ light is ____________ to your eyes and it looks BLUE absorbs ALL except BLUE reflected http://www.michaelhyatt.com/fromwhereisit/bluebook.jpg

except red reflected The dye in this T shirt absorbs all of the colors __________________________ Red wavelengths are _________________ to your eyes and the shirt looks RED except red reflected GO CATS! http://jacksbear.com/shop/index.php?main_page=product_info&products_id=9

absorbs ALL ENERGY Objects “look BLACK” because black dye ________________ of the wavelengths of light. When wavelengths are absorbed so is the_____________ of the wave. That is why wearing a black T-shirt in the summer feels warmer than wearing a white t-shirt. absorbs ALL ENERGY http://www.eventsonline.ca/events/vowsa/black_shirt.jpg http://www.hotstuffspas.com/pools_files/sunanim.gif

The dye in white objects _____________ of the wavelengths of light. _______ energy is ABSORBED so wearing white clothing is “cooler”. REFLECTS ALL LITTLE http://www.hotstuffspas.com/pools_files/sunanim.gif http://www.12stitch.com/shop/images/options/Blank-White-Shirt.jpg

(These look yellow, orange, and red) CHLOROPHYLL http://www.russianflora.com/store/images/product/custom_green_plant_35.jpg The main energy absorbing molecule in green plants is ___________________ _________________ are plant pigments too. (These look yellow, orange, and red) CHLOROPHYLL CAROTENOIDS http://www.rnzih.org.nz/images/gardenimages/carrots_d.jpg

GREEN leaves have BOTH chlorophyll AND carotenoids __________________ but the huge amount of chlorophyll ______ the other colors and leaves usually look green ALL THE TIME hides

In ______, chlorophyll production slows as the trees shut down and photosynthesis stops for winter. FALL http://sps.k12.ar.us/massengale/ecology_notes_bi.htm

carotinoid colors that are usually _______ by chlorophyll Then we can see the carotinoid colors that are usually _______ by chlorophyll HIDDEN http://www.litzsinger.org/weblog/archives/email%20AutumnTrees5%20LREC%20102605.jpg

There are two types of chlorophyll © Pearson Education, Inc. Publishing asPearson Prentice-Hall. All rights reserved. There are two types of chlorophyll __________________ & ___________________ Chlorophyll a Chlorophyll b Absorption of Light by Chlorophyll a and Chlorophyll b Chlorophyll a absorbs the _____ & ________ wavelengths best. It absorbs very little ______ light. violet red Chlorophyll b Chlorophyll a red Blue

There are two types of chlorophyll © Pearson Education, Inc. Publishing asPearson Prentice-Hall. All rights reserved. There are two types of chlorophyll __________________ & ___________________ Chlorophyll a Chlorophyll b Absorption of Light by Chlorophyll a and Chlorophyll b Chlorophyll b absorbs some ______light and even more _________ light. red Chlorophyll b Chlorophyll a Blue-violet red

NEITHER KIND OF CHLOROPHYLL IS VERY GOOD AT ABSORBING _________ LIGHT! © Pearson Education, Inc. Publishing asPearson Prentice-Hall. All rights reserved. Absorption of Light by Chlorophyll a and Chlorophyll b NEITHER KIND OF CHLOROPHYLL IS VERY GOOD AT ABSORBING _________ LIGHT! Chlorophyll b Chlorophyll a GREEN red

That’s why leaves LOOK GREEN….. http://www.russianflora.com/store/images/product/custom_green_plant_35.jpg That’s why leaves LOOK GREEN….. Chlorophyll doesn’t absorb…. it ___________ GREEN light! REFLECTS

That’s why plant have other pigments (like carotenoids) That’s why plant have other pigments (like carotenoids). They help _________ some wavelengths chlorophyll _______; so the plant can __________ of the sun’s energy. ABSORB DOESN’T USE MORE http://members.aol.com/diaspore/vhouse/biology/projects/photosynthesis/woida/meaning_of_light.html#question_1

SO WHAT WAVELENGTHS ARE BEST FOR PHOTOSYNTHESIS? © Pearson Education, Inc. Publishing asPearson Prentice-Hall. All rights reserved. Absorption of Light by Chlorophyll a and Chlorophyll b THE ONES CHLOROPHYLL ABSORBS THE BEST ________ and _______________ Chlorophyll b Chlorophyll a red Blue-violet

Pearson Education Inc, Pusblishing as Pearson Prentice Hall Because light is a form of ___________, any molecule that absorbs light also ___________the energy from the light. ENERGY ABSORBS

ENERGY & ELECTRONS When chlorophyll absorbs light, the http://www.mhhe.com/biosci/pae/botany/uno/graphics/uno01pob/vrl/images/0160.gif When chlorophyll absorbs light, the energy is transferred to electrons in the chlorophyll molecule. These electrons make ATP. HIGH ENERGY ____________ make photosynthesis work! ELECTRONS http://www.wjcc.k12.va.us/ROBB/Atom%20Animation%20Resources_files/image003.gif

Some electrons escape and energy is lost. Luckily, another energy molecule can be made, NADPH, by splitting the H2O. The plant keeps the hydrogen and releases the oxygen as a waste product. Oxygen bubbles

Summary, light reactions. Used – H2O, light, chlorophyll, Produced – Energy (ATP & NADPH), O2. Purpose – to create usable energy to fuel the dark reactions.