The Process of Photosynthesis

One timeline to understand photosynthesis: from light capture to the Calvin cycle, with narration and animation in lockstep.

About this simulation

What
An interactive Biology simulation of The Process of Photosynthesis.
Who
Designed for AP, IB, and A‑Level Biology students.
How
Runs in any modern browser — drag, adjust, and explore in real time.

Updated 2025-09-20

Key Concepts

Light Reaction

Occurs on thylakoid membranes. Converts light energy into chemical energy (ATP & NADPH) and releases O₂.

Calvin Cycle (Dark Reaction)

Occurs in stroma. Uses ATP & NADPH to fix CO₂ and produce sugars (C₃).

Energy Transformation

Light Energy → ATP Chemical Energy → Organic Matter Stable Chemical Energy.

Understanding Photosynthesis: The Engine of Life

Photosynthesis is the essential biochemical process by which autotrophic organisms transform solar energy into chemical energy stored within organic molecules, primarily serving as the primary source of chemical energy for nearly all life on Earth.

The process is architected into two integrated stages: the Light-Dependent Reactions, which capture photons on the thylakoid membranes to generate ATP, NADPH, and O₂, and the Calvin Cycle (Light-Independent Reactions), which utilizes that energy in the stroma to synthesize sugars through carbon fixation.

Press play and follow a single timeline: watch how light energy is captured, converted, and finally stored in sugar molecules.

Frequently Asked Questions