REACTIONS of PHOTOSYNTHESIS

http://vilenski.org/science/safari/cellstructure/chloroplasts.html

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 intochemical energy.

Who and Where?

• Photosynthesis occurs in the chloroplast.

• All organisms with chloroplasts can conduct photosynthesis.

Chemical Equation

Raw Materials ProductsCO2 – from animals C6H12O6 – glucose/foodH2O – water absorbed O2 – oxygen gas used byChlorophyll –plant pigment animals

Reactions of Photosynthesis

• There are two reactions involved:1. Light Reactions –

* Must have light.

* Purpose – to capture light

energy.

2. Dark Reactions –

* Don’t need light.

* Purpose – to make glucose.

Visible light is made up of many different_______________of light

Your eyes “see”different sizes ofwaves as different ___________

http://www.simontucket.com/_Portfolio/PortLarge/L_Il_Prism.jpg

wavelengths

colors

Light Energy

Many people think that plants are green because they absorb and use green light in photosynthesis,

BUT . . . .

Myth:

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

REFLECTED

COLOR

This book “looks BLUE” because the dye in this cover _______________ of the wavelengths of light _________ blue.

_______ light is ____________ to your eyes and itlooks BLUE

http://www.michaelhyatt.com/fromwhereisit/bluebook.jpg

exceptabsorbs ALL

BLUEreflected

The dye in this T shirt absorbs all of thecolors __________________________

Red wavelengths are_________________ to your eyes and theshirt looks RED

http://jacksbear.com/shop/index.php?main_page=product_info&products_id=9

except red

reflectedGO CATS!

Objects “look BLACK” because blackdye ________________ of thewavelengths of light.

When wavelengths are absorbed so is the_____________ of the wave.

That is why wearing a blackT-shirt in the summer feelswarmer than wearing a white t-shirt.

http://www.eventsonline.ca/events/vowsa/black_shirt.jpg

http://www.hotstuffspas.com/pools_files/sunanim.gif

absorbs ALL

ENERGY

The dye in white objects _____________ of the wavelengths of light.

_______ energy is ABSORBED so wearing whiteclothing is “cooler”.

REFLECTS ALL

LITTLE

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

The main energy absorbing moleculein green plants is___________________

_________________ are plant pigments too.(These look yellow, orange, and red)

CAROTENOIDS

http://www.russianflora.com/store/images/product/custom_green_plant_35.jpg

http://www.rnzih.org.nz/images/gardenimages/carrots_d.jpg

CHLOROPHYLL

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

Then we can see thecarotinoid colors that are usually _______ by chlorophyll

http://www.litzsinger.org/weblog/archives/email%20AutumnTrees5%20LREC%20102605.jpg

HIDDEN

red

Chlorophyll a

Chlorophyll b

Absorption of Light byChlorophyll a and Chlorophyll b

© Pearson Education, Inc. Publishing asPearson Prentice-Hall. All rights reserved.

There are two types of chlorophyll__________________ & ___________________

Chlorophyll a absorbs the_____ & ________wavelengths best.

It absorbs very little ______ light.

Chlorophyll a Chlorophyll b

red violet

Blue

red

Chlorophyll a

Chlorophyll b

Absorption of Light byChlorophyll a and Chlorophyll b

© Pearson Education, Inc. Publishing asPearson Prentice-Hall. All rights reserved.

There are two types of chlorophyll__________________ & ___________________

Chlorophyll babsorbs some ______light and even more_________ light.

Chlorophyll a Chlorophyll b

red

Blue-violet

red

Chlorophyll a

Chlorophyll b

Absorption of Light byChlorophyll a and Chlorophyll b

© Pearson Education, Inc. Publishing asPearson Prentice-Hall. All rights reserved.

NEITHER KIND OF CHLOROPHYLL IS VERY GOOD AT ABSORBING _________ LIGHT!GREEN

That’s why leaves LOOK GREEN…..

Chlorophyll doesn’t absorb…. it ___________ GREEN light!

http://www.russianflora.com/store/images/product/custom_green_plant_35.jpg

REFLECTS

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

USE MORE

ABSORB

DOESN’T

Chlorophyll a

Chlorophyll b

Absorption of Light byChlorophyll a and Chlorophyll b

© Pearson Education, Inc. Publishing asPearson Prentice-Hall. All rights reserved.

SO WHAT WAVELENGTHS ARE BEST FOR PHOTOSYNTHESIS?

THE ONESCHLOROPHYLLABSORBS THE BEST________ and_______________

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 energy is transferredto electrons in the chlorophyll molecule.These electrons makeATP.

http://www.mhhe.com/biosci/pae/botany/uno/graphics/uno01pob/vrl/images/0160.gif

http://www.wjcc.k12.va.us/ROBB/Atom%20Animation%20Resources_files/image003.gif

HIGH ENERGY ____________make photosynthesis work!

ELECTRONS

Some electrons escape and energy is lost.

Luckily, another energy molecule can bemade, NADPH, by splitting the H2O.

The plant keeps the hydrogen and releasesthe oxygen as a wasteproduct.

Oxygen bubbles

Summary, light reactions.

Used – H2O, light, chlorophyll, Produced – Energy (ATP & NADPH), O2.

Purpose – to create usable energy to fuel the dark reactions.