REACTIONS of PHOTOSYNTHESIS

THE BIG PICTURE In the presence of light, plants transform CO 2 and water into carbohydrates and release oxygen. _____________ + ____________ _______________ + ____________ Carbon dioxide WATERSugars Oxygen 6 CO 2 _____________ + ____________ _______________ + ____________ 6 H 2 OC 6 H 12 O 6 6 O 2 →

In addition to water and carbon dioxide, __________________ and __________________ are needed for photosynthesis to happen. chlorophyll light energy

____________________ involves a complex series of chemical reactions, in which the product of one reaction is _____________ by the next reaction. Photosynthesis consumed Reaction 1 →Product → X Reaction 2 → Product Y A series of reactions linked in this way is referred to as a __________________________ biochemical pathway

PHOTOSYNTHESIS Light-Dependent Reaction Light-Independent Reactions Light & Water oxygen ATP NADPH Carbon Dioxide (CH 2 O) n Calvin Cycle

PHOTOSYNTHESIS: Reactants & Products LIGHT ENERGY 6CO 2 + 6H 2 OSUGAR + 6O 2

Sunlight is made up of many different _______________ of light Your eyes “see” different wavelengths as different ___________ wavelengths colors

Sizes of Wavelengths

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

The main energy absorbing molecule in green plants is ___________________ _________________ are pigments too. (These look yellow, orange, and brown) CAROTENOIDS CHLOROPHYLL

Carotenoids are usually _______ by the presence of _______________ HIDDEN chlorophyll

When chlorophyll ____________ in the _______, we can see the carotenoid colors that are there ____________, but are no longer hidden. DISAPPEARS FALL ALL THE TIME

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

red Chlorophyll a Chlorophyll b Absorption of Light by Chlorophyll 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 plant have other pigments (like carotenoids). They help _________ some wavelengths chlorophyll _______; so the plant can __________ of the sun’s energy. USE MORE ABSORB DOESN’T

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

Chlorophyll b Chlorophyll a Absorption of Light by Chlorophyll a and Chlorophyll b © Pearson Education, Inc. Publishing as Pearson Prentice-Hall. All rights reserved. REMEMBER: Chlorophyll a & b ______________ absorb _______________ wavelengths of light do NOT green

Why are plants green? BECAUSE… Chlorophyll _____________ light very well in the __________________ regions and _________ light in the green regions of spectrum. absorbs blue-violet and red reflects

We “see” reflected light Light wavelengths that are ___________ bounce back to your eyes... so leaves “LOOK” green. Image modified from: ___________________________________ REFLECTED

When you see a plant with yellow flowers and green leaves, the plant is ____________________________ wavelengths of light reflecting yellow and green By: VanderWal

When you see a plant with __________ and __________ flowers, the plant is reflecting yellow and purple wavelengths of light. By: VanderWal purpleyellow

Plants ________________ mainly ___________________________ wavelengths of light for photosynthesis. red and blue-violet By: VanderWal absorb and use

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 transferred to electrons in the chlorophyll molecule. HIGH ENERGY ____________ make photosynthesis work! ELECTRONS