Alternative mechanism of carbon

Also known as CALVIN BENSON CYCLE / LIGHT INDEPENDENT REACTION

It's main purpose is to convert C02 from the atmosphere into carbohydrates/sugar

• Occur within the stroma of the chloroplast • Uses the chemical energy of ATP and NADPH to convert the Co2 to carbohydrates

3 Phases of the Calvin cycle

The incorporation of CO2 molecules, by attaching it one at a time to a five carbon sugar named sibulose Biophosphate (RuBP)

Enzyme involve: Carboxylaseoxygenase or Rubisco

Enzyme involve

Product 2: 2 molecules of 3 phosphoglycerates)(for each co2 fixed)

Carbon fixation product

Each molecule of 3 phosphoglycerates is energized by an ATP by receiving an additional phosphate + becoming 1,3-biophoshoglycerate

A pair of electrons are denotes from NADPH that results to the reduction of 1,3 - biophoshoglycerate to get G3P

The carbon skeleton of five molecules of G3P is rearranged into three molecules of RuBP by spending 3 more molecules of ATP

For every molecule of co2 that enters the cycle, the net output is one molecule of glyceraldehyde 3 - phosphate (G3PO, a three carbon sugar)

The first organic product of carbon fixation is a three carbon compound 3 phosphoglycerates

Ex of C3 plants

Occurs in the light (photo) and consumes 02 while producing C02 (respiration)

Occurs in the light

Consumes 02 while producing co2

Preface the Calvin cycle with an alteration mode of carbon fixation that forms a four carbon compound as it's first product

Ex of C4 plants

Bundle sheath cells and Mesophyll

Where incorporation of CO2 into organic compounds happens

Are araanged tightly packed sheaths around the veins of the leaf It is where the Calvin cycle happens

Cucculemts and grow in dry regions due to excessive heat, the stomach remain closed during the day to reduce transpiration. Their stromata open at night

Five carbon sugar

RuBP

It is the process of fixing CO2 to an organic compound and reducing it to carbohydrate

RuBP

G3P

CAM