Photosynthesis + Calvin cycle

What is photosynthesis?

The conversion of light energy to chemical energy

Where is the site of photosynthesis?

leaves

What is the organelle for the location of photosynthesis?

Chloroplast

Where is chloroplast found?

mesophyll

What is the purpose of stomata?

to allow carbon dioxide in and oxygen out

What are the structures of a chloroplast?

stroma, thylakoid membrane, grana, inner and outer membranes

What do pigments do

absorb light energy

What is the purpose of chlorophyl B

To expand the usable, light spectrum and protect chlorophyl from damage

What is the formula for photosynthesis?

6CO2 + 6H2O + energy --> C6H12O6 + 6O2 + 6H2O

What is oxidation and reduction?

Oxidation is the loss of electrons and reduction is the gain of electrons

What are the three possibilities after chlorophyl absorbs a photo of light and the electron is boosted to a higher energy level

It will fall back down to ground state and release his energy as heat

The energy from the excited electron is passed to another pigment molecule, exciting the molecule and repeating the process

Excited electron is passed from pigment molecule to electro accepting molecule (primary acceptor)

Where do light reactions occur?

thylakoid membrane

What is the purpose of light reaction?

To convert solar energy into chemical energy in the form of ATP and NADPH.

When do light reactions begin?

When light is absorbed by chlorophyll a pigments in the photosystems

What is a photo system?

Clusters of pigments and proteins that capture light energy

Where do photosystems absorb light at?

Photosystem one absorbs light at 700 nm and photo system two absorb light at 680 nm

How do P680+ and P700+ form

When the electron gets excited and is transferred to a primary electron acceptor

Why is P680+ a strong oxidizing agent

Because it takes electrons

When does splitting of water occur?

In Photos system 2 when it replaces its loss electron by taking the electrons from water

How do electrons pass from photo system two to photo system one

Through the electron transport chain

What happens in photosystem one?

Electrons are excited to a higher energy level by absorbing more light energy then electrons are transferred to NADP plus reducing it to NADPH

What is the process of electrons being removed from water and passed from PS2 to PS1 before ending an NADPH

Photophosphorylation

How is ATP formed?

When H+ flows down its gradient passing through ATP synthase the H+ gives the ATP energy for ADP + P to synthesize and form ATP

What does the Kelvin cycle produce and what are the reactants?

It produces carbohydrates from CO2 and it uses ATP and NADPH

What are the three phases of the Calvin cycle?

carbon fixation, reduction, RuBP regeneration

How many times must the cycle take place for one G3 P molecule and why?

The cycle must take place three times because CO2 is incorporated into the cycle one at a time

What enzyme is the Kelvin cycle catalyzed by?

Rubisco

What does CO2 attach to in the Kelvin cycle?

RuBP

What is the product of CO2 and RUBP

3-PGA

how does 3-PGA turn into G3P

ATP phosphorylates 3-PGA into an intermediate, then NADPH reduces the intermediate by (donating an e- )forming G3P

How does RuBP regenerate?

By using 5 of the 6 G3P molecules formed

What needs to be used for 3 RuBP regeneration

5 G3P and 3 ATP

Why is it problematic when C3 plants close their stomata on hot days

Causes less CO2 and more O2 and rubisco binds to O2. No sugar is produced and it is bad for the plant

What adaptation do C4 plants have to continue the Calvin cycle

Stomata partially close to conserve water, still allowing CO2 and O2 to transfer

How do C4 plants continue the Calvin cycle

Mesophyll cells fix CO2 into a 4-C molecule, then are transferred to bundle sheath cells. Then CO2 is released and used in the Calvin cycle

What kind of plants open their stomata during the night and close during the day

CAM plants

How is CO2 stored in CAM plants?

Incorporated into organic acids and stored in vacuoles, then incorporated into the Calvin cycle