4.1 Capturing Solar Energy lesson

Photosynthesis

The process of converting light energy into chemical energy, such as glucose, enabling plants to produce vital substances like cellulose and starch.

Light-dependent reactions

Reactions that produce ATP and NADPH by trapping light energy, essential for subsequent glucose synthesis in the Calvin Cycle.

Chlorophyll

A green pigment that absorbs light energy to initiate photosynthesis, reflecting green light and playing a key role in capturing solar energy.

Thylakoids

Interconnected disks within chloroplasts that absorb light energy, often stacked to form grana, where light-dependent reactions occur.

Pigments

Compounds that absorb specific wavelengths of light, trap light energy, and transfer it to other compounds, crucial for photosynthesis.

Photosystems

Protein-based complexes with pigments that absorb light energy, consisting of antenna complexes and reaction centers like Photosystem I (P700) and Photosystem II (P680).

Photoexcitation

Process where chlorophyll absorbs photons, energizing electrons, and transferring them through Photosystems to generate ATP and NADPH.

Electron Transport

Involves non-cyclic flow of electrons along carriers, facilitated by a water-splitting enzyme to release O2 and generate H+ ions.

Cyclic Electron Flow

Utilizes Photosystem I to generate ATP but not NADPH, contributing to the overall energy production in photosynthesis.

Chemiosmosis

Formation of a proton gradient across the thylakoid membrane, driving ATP synthesis through ATP synthase via phosphorylation, known as photophosphorylation.