Photosynthesis

Photosynthesis

The process of converting CO₂ and H₂O into organic molecules (glucose) and O₂ using light energy

Chloroplasts

Where photosynthesis occurs

Redox Reaction

The kind of reaction that photosynthesis is

Light-Dependent, Light-Independent

Kinds of reactions that occur in chloroplasts during photosynthesis (2)

Light-Dependent Reactions

Occurs in thylakoid membrane, Captures light energy and produces ATP, NADPH, and O₂

Light-Independent Reactions

Occurs in the stroma, Produces carbohydrates and converts ATP and NADPH back into ADP and NADH+, aka Dark Reactions and Calvin Cycle

Resonance Energy Transfer

The transfer of energy to an electron of a nearby molecule

By transferring the excited electron to another molecule

How energy can be captured during photosynthesis

P680

Pigments that capture light in photosystem II’s light harvesting complex when it starts the chain, Process splits H₂O and H⁺ gradient

P700

Pigment that allows photosystem I to capture light

Plastocyanin (Pc)

Structure that gives Photosystem I its electron

O₂

_NADPH

_ATP

Net production of molecules following the light-dependent reactions

Light-Harvesting Complex

Structure in photosystem II that absorbs light energy

Reduced Primary Electron Acceptor

Structure in photosystem II that receives high-energy electrons from P680, Very stable

Phenophytin

The primary electron acceptor in photosystem II

Stroma

Where the Calvin Cycle occurs

Rubisco

Most abundant protein on earth, Enzyme that catalyzes the reaction between CO₂ and RuBP to create 3-carbon 3PG during the Calvin Cycle

12 NADP⁺

18 ADP + P

Glucose (and other carbs)

Net Production of molecules following light-independent reactions

Photorespiration

Occurs when CO₂ levels are low and O₂ levels are high and/or in hot and dry environments, Stomata close to conserve water but results in the prevention of uptake of CO₂, Considered wasteful because it releases CO₂

C₃ Plants

Plants that fix CO₂ by reacting with 6-carbon RuBP and producing 3-carbon 3PG via Rubisco, Includes most of the plants we think of

C₄ Plants

Plants that have evolved to minimize photorespiration by fixing CO₂ with a 3-carbon Phosphoenolpyruvate to produce the 4-carbon Oxaloacetate via PEP carboxylase, Includes sugarcane, crabgrass, and corn

CAM Plants

Specialized C₄ plants that close their stomata during the day to incorporate it into Malate until the day when CO₂ is released and used to drive the Calvin Cycle, Includes succulents and cacti

3-carbon 3PG

Produced in C₃ plants by Rubisco, which catalyzes a reaction between CO₂ and 6-carbon RuBP

4-carbon Oxaloacetate

Produced in C₄ plants PEP carboxylase, which catalyzes a reaction between CO₂ and 3-carbon Phosphoenolpyruvate, which minimizes photorespiration