5.3 The Calvin Cycle Practice Flashcards

Detailed vocabulary flashcards covering the stages, chemical reactions, and biological significance of the Calvin cycle based on the provided lecture notes.

Calvin cycle

The reactions of photosynthesis that use the energy stored by the light-dependent reactions to form glucose and other carbohydrate molecules.

Stomata

Openings in the leaf through which $CO_2$ enters and oxygen is released.

Stroma

The site within the chloroplast where the Calvin cycle reactions take place and sugar is synthesized.

Melvin Calvin

The scientist who discovered the reactions of the Calvin cycle.

Calvin-Benson cycle

An alternative name for the Calvin cycle that includes the name of scientist Andrew Benson.

RuBisCO

The enzyme that catalyzes a reaction between $CO_2$ and RuBP, initiating the process of carbon fixation.

Ribulose bisphosphate (RuBP)

A molecule with five atoms of carbon and a phosphate group on each end that reacts with $CO_2$ to start the Calvin cycle.

Carbon fixation

The process of converting $CO_2$ from its inorganic form into organic molecules.

3-PGA

The three-carbon compound formed immediately after $CO_2$ is fixed to RuBP.

G3P

A three-carbon compound formed during the reduction stage of the Calvin cycle using energy from ATP and NADPH.

Reduction reaction

A chemical reaction involving the gain of an electron by an atom or molecule.

Six

The number of turns of the Calvin cycle required to fix six carbon atoms from $CO_2$ to produce one carbohydrate molecule like glucose.

Glucose chemical formula

$$C_6H_{12}O_6$$

Energy requirements for six turns

The process requires energy input from $12$ ATP molecules and $12$ NADPH molecules for reduction and $6$ ATP molecules for regeneration.

Cyanobacteria

Prokaryotic photosynthetic autotrophic organisms that use infoldings of the plasma membrane to carry out photosynthesis due to a lack of membrane-bound organelles.

Overall reaction for photosynthesis

$$6CO_2 + 6H_2O \rightarrow C_6H_{12}O_6 + 6O_2$$

Overall reaction for cellular respiration

$$6O_2 + C_6H_{12}O_6 \rightarrow 6CO_2 + 6H_2O$$