The Calvin Cycle (Chapter 7)

Pigments

Molecules that absorb only certain wavelengths ex: chlorophyll

How does the cycle start over?

More chemistry happens to molecules in the chloroplast to get back to the 5-carbon Ribose sugar so the cycle can start over.

Pheophytin

Primary electron receptor in PS II

What sugar is always available in the stroma that starts this cycle?

Ribose sugar - a 5-carbon chain. It has 5 carbons, 10 hydrogens and 5 oxygens.

P700

Specialized chlorophyll molecule in Photosystem I

P680

Specialized chlorophyll molecule in Photosystem II

Where does the Calvin Cycle occur?

The entire process happens in the stroma of the chloroplasts.

What happens to the two hydrogens stored in the Light Dependent Reaction?

These are removed from NADP and are bonded to the the two newly arranged 3-carbon chains.

What happens to the new 6-carbon chain?

This chain is unstable and breaks in half to form two 3-carbon chains

electron transport chain

moves high energy electrons from PS II to PS I.

Calvin cycle

uses ATP and NADPH from the light-dependent reactions to produce a single 6-carbon sugar molecule.

What is the waste molecule from the Calvin Cycle?

water

Flourescence

Electron is excited then returns to ground state, heat or light is emitted

photosystem II

Light energy absorbed by the pigment, electrons passed to the electron transport chain, electrons restored to chlorophyll by breaking H2O into 2 H+ ions and 1 oxygen atom.

Photophosphorylation

The process by which H+ exits the thylakoid membrane due to the large proton gradient, which drives the phosphorylation of ADP into ATP

photosystem I

light energizes electrons again, enzymes in the thalakoid membrane use electrons and H+ to form NADPH.

Photosynthesis

Biochemical process through which green plants create food from sunlight

Resonance

Electrons are transferred to nearby pigments until it reaches a specialized chlorophyll molecule that acts as an electron acceptor

Why is ATP used in the Calvin Cycle?

Energy is needed to rearrange the two 3-carbon chains so that the stored Hydrogens can be added to them.

What is the product of the Calvin Cycle after repeating 6 times?

Glucose

hydrogen ion movement

H+ ions fill up the inside of the thalakoid membrane creating a positively charged interior and a negatively charged exterior.

light-dependent reactions

Produce oxygen gas and convert ADP and NADP+ into the energy carriers ATP and NADPH.

Grana

Stacks of thylakoids

What is the role of carbon dioxide in photosynthesis.

This gas adds a 6th carbon to ribose in order to start forming glucose.

What is the purpose of the Calvin Cycle?

This phase uses the ATP and stored Hydrogens made in the previous phase to make glucose.

Where does the ATP for the Calvin Cycle come from?

This stored energy molecule was made by the Light Dependent Reaction.

ATP synthase

protein spanning the membrane that converts ADP into ATP.