Cell Bio- Calvin Cycle

What are the 3 phases of the Calvin Cycle?

1. Carbon fixation

2. Reduction

3. Regeneration of RuBP

When carbon enters the cycle as CO2 and leaves as a sugar named ___?

Glyceraldehyde-3-phosphate (G3P)

What is carbon fixation?

The bonding of CO2 to an organic molecule

What is Rubisco?

An enzyme that catalyzes CO2 fixation reaction

Co2 binds?

Ribulose Biphosphate (RuBP)

RuBP is called the ___?

CO2 acceptor

Is a 5-carbon sugar

What is reduction?

6 ATP are used to phosphorylate the six 3-carbon molecules

Electrons from 6 NADPH reduce the 6 molecules to G3P

Six G3P are produced, one G3P leaves the cycle as a product

What is the regeneration of RuBP?

The other five G3P remain in the cycle and are rearranged to become three RuBP

Requires 3 ATP

5 × 3-carbon molecules become 3 × 5 carbon molecules

On hot, dry days, plants close their ____?

Stomata

What does closing their stomata lead to?

Photorespiration

An energy wasteful process in C3 plants

In photorespiration:

-Rubisco has a higher affinity for O2 than CO2 so it binds O2

-Calvin cycle runs with O2 instead of CO2 burning ATP without making sugar

-Energy wasteful process- uses up ATP with no useful product made

In C4 plants:

Separates CO2 collection from the Calvin cycle using space

Collected in a different cell

In CAM plants:

Separate CO2 collection from the Calvin cycle using time

Collects at night

O2 waste products come from:

H2O