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

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://ninenet.pbslearningmedia.org/resource/tdc02.sci.life.stru.photosynth/photosynthesis/ http://www.nofretete-page.de/gemischtNeu/TN_plant_grow_w.JPG

Discussion Questions Do you think that the factory is a good analogy for the process of photosynthesis in plants? Why did von Helmont think that plants got their nourishment from soil? Why did he eliminate soil as a source of nourishment and focus on water? What did he measure to find out if the willow plant got its nourishment from soil? What do you think von Helmont concluded when he measured the change in weight of the plant and the soil?

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 2 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

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. Carbon dioxide WATER Sugars Oxygen _____________ + ____________ _______________ + ____________ 6 CO2 6 H2O → C6H12O6 6 O2 _____________ + ____________ _______________ + ____________

chlorophyll light energy In addition to water and carbon dioxide, _______________(green) __ and __________________ are needed for photosynthesis to happen. http://fig.cox.miami.edu/~cmallery/255/255phts/255phts.htm chlorophyll light energy

See a video about PHOTOSYNTHESIS 8B

PHOTOSYNTHESIS: Reactants & Products LIGHT ENERGY 6CO2 + 6H2O SUGAR + 6O2 So light drives the reaction! Draw Me!!!

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

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

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

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

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

(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

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

CFU!!! 1. Where do plants get the energy they need to grow? 2. What ingredients (raw materials) do green plants need for photosynthesis? 3. Where do plants get these ingredients? 4. In what part of the plant does photosynthesis take place? 5. What do plants use the sun’s energy to manufacture? 6. What do they use the energy stored in glucose for? 7. What gas do animals exhale and plants take in? What do plants use this gas for? 8. What gas do plants give off and animals inhale? 10. Why are plants called producers? 11. Green plants make their own food from 1) __________ that is absorbed by the roots and travels up the stem to the leaves; 2) a gas in the air, called __________; and 3) energy from __________, which the green leaves trap.

THE BIG PICTURE Very important to remember what goes into a plant and then what comes out. Also known as the reactancts (going in) and the products (coming out) Put many stars next to this in your notes Carbon dioxide WATER Sugars Oxygen _____________ + ____________ _______________ + ____________ 6 CO2 6 H2O → C6H12O6 6 O2 _____________ + ____________ _______________ + ____________

Remember from CELL BIO CHLOROPLASTS Enzymes for PHOTOSYNTHESIS are in the ________________ CHLOROPLASTS http://www.science.siu.edu/plant-biology/PLB117/JPEGs%20CD/0076.JPG

PHOTOSYNTHESIS HAPPENS IN CHLOROPLASTS THYLAKOIDS = sac-like photosynthetic membranes inside chloroplast Image from BIOLOGY by Miller and Levine; Prentice Hall Publishing©2006

Factors that Affect Photosynthesis AMOUNT OF WATER ____________________ Water is one of the raw materials needed, so A shortage of water can ________________ photosynthesis slow or stop Desert plants and conifers that live in dry conditions have a waxy coating on their leaves to prevent water loss. http://www.hononegah.org/departments/Anderson/cactus.JPG

Factors that Affect Photosynthesis TEMPERATURE Photosynthesis enzymes function best between 0° C - 35° C At temperatures above or below this range, photosynthesis will slow or stop Conifers in winter may carry out photosynthesis only occasionally http://www.sustland.umn.edu/maint/images/evergreen10.jpg

Factors that Affect Photosynthesis LIGHT INTENSITY ____________________ More light increases rate of photosynthesis up to a certain level until plant reaches its maximum rate of photosynthesis http://206.173.89.42/REALTYWITHALOHA_COM/piphoto/funny%20sun%20with%20sunglasses.gif

THE BIG PICTURE sugars PHOTOSYNTHESIS provides the _____________ we breathe and the __________heterotrophs consume to survive OXYGEN sugars Carbon dioxide Sugars WATER Oxygen _____________ + ____________ _______________ + ____________

Check For Understanding Write the equation for Photosynthesis. Increasing the intensity of light will _______ Photosynthesis. The name of the organelle that allows plants to do photosynthesis is _________. Decreasing the amount of water will _________ Photosynthesis. Plants in Alaska where its colder will do (more or less) photosynthesis than plants in Florida?

Core High School Life Science Performance Descriptors High school students performing at the ADVANCED level: explain the steps of photophosphorylation and the Calvin Cycle; analyze chemical reaction and chemical processes involved in the Calvin Cycle and Krebs Cycle; predict the function of a given structure; predict how homeostasis is maintained within living systems PROFICIENT level: describe and give examples of chemical reactions required to sustain life (hydrolysis, dehydration synthesis, photosynthesis, cellular respiration, ADP/ATP, role of enzymes); describe the relationship between structure and function explain how homeostasis is maintained within living systems; predict how life systems respond to changes in the environment; BASIC level name chemical reactions required to sustain life (hydrolysis, dehydration synthesis, photosynthesis, cellular respiration, ADP/ATP, role of enzymes); recognize that different structures perform different functions; define homeostasis;