JB_Photosynthesis_Has_Evolved_Through_Time

Photosynthesis

The process by which green plants and some other organisms use sunlight to synthesize foods with the help of chlorophyll.

Rubisco

An enzyme that catalyzes the fixation of carbon dioxide during the Calvin cycle.

Calvin Cycle

A series of chemical reactions that take place in the stroma of chloroplasts during photosynthesis.

Photorespiration

A process in plants where the enzyme Rubisco reacts with oxygen instead of carbon dioxide, leading to a decline in photosynthetic efficiency.

C3 Pathway

A photosynthetic pathway where CO2 is first incorporated into a three-carbon compound, 3-phosphoglycerate.

C4 Pathway

A photosynthetic process that incorporates CO2 into a four-carbon compound (malate) and utilizes PEP carboxylase.

CAM Pathway

A photosynthetic adaptation where CO2 is fixed at night and stored as malic acid, then used during the day.

Malate

A four-carbon compound formed from carbon dioxide during the CAM pathway.

NADPH

An electron carrier that provides the reducing power for the Calvin cycle.

Thylakoid

Membrane-bound compartments inside chloroplasts where the light reactions of photosynthesis occur.

Granum

A stack of thylakoids within a chloroplast.

Stroma

The fluid-filled space inside chloroplasts where the Calvin cycle occurs.

Bundle Sheath Cells

Cells that surround the vascular tissue in C4 plants and are involved in the C4 photosynthetic pathway.

3-PGA (3-Phosphoglycerate)

A three-carbon intermediate in the Calvin cycle.

PEP Carboxylase

An enzyme that catalyzes the fixation of CO2 to phosphoenolpyruvate in C4 photosynthesis.

Kranz Anatomy

The specialized anatomy of leaves in C4 plants characterized by a ring of bundle sheath cells surrounding the vascular tissue.

Carbon Concentration Mechanism

A method used by some plants to increase the concentration of CO2 at the site of photosynthesis to maximize efficiency.

Oxygenase Activity

The ability of Rubisco to react with oxygen instead of carbon dioxide, leading to photorespiration.

Carboxylase Activity

The ability of Rubisco to catalyze the reaction of ribulose bisphosphate with carbon dioxide.

Environmental Conditions

The external factors that influence the adaptations and efficiency of different photosynthetic pathways.

G3P (Glyceraldehyde-3-Phosphate)

A three-carbon sugar produced during the Calvin cycle that is a precursor to glucose.

Chloroplast

An organelle found in plant cells that is responsible for photosynthesis.

Light Capture Reactions

The phase of photosynthesis where light energy is converted into chemical energy.

Carbon Dioxide (CO2)

A gas that is a key reactant in the process of photosynthesis.

Oxygen (O2)

A byproduct of photosynthesis released into the atmosphere.