REACTIONS of PHOTOSYNTHESIS 8-2 http://vilenski.org/science/safari/cellstructure/chloroplasts.html REACTIONS of PHOTOSYNTHESIS 8-2 http://www.science.siu.edu/plant-biology/PLB117/JPEGs%20CD/0076.JPG

An chemical equation tells what happens in a chemical reaction when molecules interact. NaOH + HCl → NaCl + H20 ______________ _______________ Molecules that react Molecules that are produced → http://www.epa.gov/region5/superfund/ecology/images/fishcartoon.gif

Research into PHOTOSYNTHESIS began centuries ago with this simple question: When a tiny seed grows into a huge plant, where does all the “new plant” come from? http://www.nofretete-page.de/gemischtNeu/TN_plant_grow_w.JPG

EXPERIMENTS TO FIND OUT a Belgian physician ___________________ determined the mass of a pot of dry soil and a small seedling. Jan van Helmont Then he planted the seedling in the pot and watered it regularly. At the end of 5 years the _____________ __________about 75 kg, but the mass of the _________ was almost ________________. seedling had gained soil unchanged He decided the “increase in plant” had to come from the ________… that was the only thing he had added! WATER http://www2.nsta.org/Energy/find/primer/primer2_3.html

EXPERIMENTS TO FIND OUT Van Helmont didn’t realize the major contribution to the mass of his tree was something he couldn’t see… __________________ from the air. carbon dioxide Plants use _______ and ______ dioxide to make ___________________ water carbon Carbohydrates http://www2.nsta.org/Energy/find/primer/primer2_3.html

EXPERIMENTS TO FIND OUT 1771- An English minister, _________________________, discovered that a flame burning in a closed jar would die out. If he placed a __________ in the jar and allowed a few days to pass, the candle could be lit again. Joseph Priestley http://www2.nsta.org/Energy/find/primer/primer2_7.html http://www2.nsta.org/Energy/find/primer/primer2_8.html live plant The plant produced something “required for burning” that the candle used up OXYGEN We now know it was …____________

EXPERIMENTS TO FIND OUT 1779- Dutch scientist ________________________ showed Priestley’s plant experiment only worked if the plant was exposed to _________________ ! Jan Ingenhousz light http://www.rgg.og.schule-bw.de/Dokus/d-faech/Biologie/Klasse%208/Bilder/Fotosynthese/Ingenhousz-Netz.JPG

EXPERIMENTS TO FIND OUT http://www.bookrags.com/Melvin_Calvin 1961- American chemist ________________________ received the Nobel prize for figuring out the chemical _______________ used by plants to make sugar Melvin Calvin pathway http://www.daviddarling.info/encyclopedia/C/Calvincycle.html

THE BIG PICTURE → These experiments led to work by later scientists who finally discovered that in the presence of light, plants transform CO2 and water into carbohydrates and release oxygen. _____________ + ____________ _______________ + ____________ → _____________ + ____________ _______________ + ____________

In addition to water and carbon dioxide, __________________ and are needed for photosynthesis to happen. http://fig.cox.miami.edu/~cmallery/255/255phts/255phts.htm

PHOTOSYNTHESIS Light-Dependent Reaction oxygen Light & Water ATP NADPH (CH2O)n Carbon Dioxide Light-Independent Reactions Calvin Cycle

PHOTOSYNTHESIS: Reactants & Products LIGHT ENERGY 6CO2 + 6H2O SUGAR + 6O2

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” Image modified from: http://www.visibledreams.net/Web/color/color_3.html

absorbs ALL except 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 http://www.michaelhyatt.com/fromwhereisit/bluebook.jpg

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

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. 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”. http://www.hotstuffspas.com/pools_files/sunanim.gif http://www.12stitch.com/shop/images/options/Blank-White-Shirt.jpg

Which wavelengths of light are these Flowers REFLECTING? Images by: VanderWal

Which wavelengths of light do these LEAVES reflect? So green leaves ____________ the green wavelength of light. Image by: VanderWal

Plants gather the sun’s energy with light absorbing molecules called ___________. By: VanderWal

(These look yellow, orange, and red) 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) 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

In ______, chlorophyll production slows as the trees shut down and photosynthesis stops for winter. 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 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 __________________ & ___________________ 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 __________________ & ___________________ 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 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!

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. 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

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.