Chapter 6: Cell Energy: Photosynthesis and Respiration

Chapter 6: Cell Energy: Photosynthesis and Respiration

Section 2: Photosynthesis: The Light and Dark Reactions

Photosynthesis: The Light and Dark Reactions

The production of ______and ______requires ______

o______– the energy of sunlight is captured and used to make energy-storing compounds

oAnother set of reactions called the ______

______uses the energy stored in NADPH and ATP to produce ______

Do not ______

However, they ______and ______occur in the light also

The Light Reactions

Photosynthesis takes place in the ______

oWithin the chloroplast are saclike ______

______that contain chlorophyll

oLight reactions take place in these membranes

Can be divided into four basic processes: light absorption, electron transport, oxygen production, and ATP formation

Light Absorption

Photosynthetic membranes contain clusters of pigment molecules, or ______, that are able to capture the energy of sunlight

oTwo photosystems in plants

______

______

Each contains ______chlorophyll molecules as well as other ______

oAbsorb light in the regions of the spectrum where chlorophyll does not

After light energy is absorbed by one of the pigment molecules in a photosystem, the energy is passed from one pigment molecule to the next until it reaches a special pair of chlorophyll molecules in the reaction center of the photosystem

oIn the reaction center, ______are released and are passed to the first of many ______

Electron Transport

High-energy electrons are transferred along a series of electron carriers

o______the electron carriers themselves are known as the electron transport chain

At the end of the chain, the electrons are passed to ______, converting it to ______

Oxygen Production

The photosynthetic membrane contains a system that provides ______to chlorophyll to replace the ones that wound up in ______

o______are removed from ______

______

4 H+ ions

2 O atoms

Form a single molecule of ______

o______

ATP Formation

______are released inside the photosynthetic membrane as well as being pumped ______the membrane

The inside of the membrane ______with H+ ions

Makes the outside ______and the inside ______

o______

A Summary of the Light Reactions

Use water, ADP, NADP+

Produce O2, ATP and NADPH

oThe dark reactions will convert these energy-storing molecules to a more convenient form

The Dark Reactions

______does not play a role in the dark reactions

The series of chemical changes that make up the dark reactions is critical to living things

______is used to make organic compounds

The dark reactions form a cycle called the ______

______

The Calvin Cycle

5 carbon sugar ______combines with ______to form two 3 carbon compounds ______

oRelatively slow

Uses the enzyme ______to speed up the process

Using ______and ______, the 3 carbon compounds are converted to ______(phosphoglyceraldehyde)

o______to make one molecule of ______