Interactive Course

Cell Biology
Organelles & Energy

Explore the inner workings of cells through interactive simulations. From organelle structure to the energy pathways that power all life.

Begin Exploring →
6
Simulations
20
Quiz Questions
∞
Interactions
01 — Cell Structure

Interactive Cell Explorer

Click on organelles to learn about their structure and function. Toggle between animal and plant cell views.

Select an organelle
Hover over or click on any organelle in the cell above to learn about its structure and function.
02 — Membrane Transport

Membrane Transport

Watch molecules cross the cell membrane via diffusion, osmosis, and active transport. Control concentration gradients in real time.

Passive Diffusion
Small nonpolar molecules move freely across the lipid bilayer from areas of high concentration to low concentration, driven by the concentration gradient. No energy is required.
03 — Powerhouse of the Cell

Mitochondria & ATP Production

Visualize the electron transport chain and oxidative phosphorylation in the inner mitochondrial membrane.

Electron Transport Chain
Electrons from NADH and FADH₂ pass through four protein complexes (I–IV) embedded in the inner mitochondrial membrane. This drives proton pumping from the matrix to the intermembrane space, creating the electrochemical gradient that powers ATP synthase.
04 — Metabolic Pathways

Glycolysis & Krebs Cycle

Follow glucose as it is broken down step by step, from glycolysis in the cytoplasm to the Krebs cycle in the mitochondrial matrix.

Glycolysis (10 Steps)
Glycolysis occurs in the cytoplasm and converts one molecule of glucose (6C) into two molecules of pyruvate (3C), yielding a net gain of 2 ATP and 2 NADH. It does not require oxygen.
05 — Light to Life

Photosynthesis

Explore how chloroplasts capture light energy and convert it to chemical energy through the light reactions and the Calvin cycle.

Light Reactions
Occur in the thylakoid membranes. Photosystem II absorbs light, splitting water molecules and releasing O₂. Electrons pass through the electron transport chain to Photosystem I, generating ATP and NADPH for the Calvin cycle.
06 — The Big Picture

Energy Pathways Compared

Compare ATP yields, inputs, and outputs across all the major metabolic pathways in one interactive diagram.

Cellular Respiration Overview
Complete oxidation of one glucose molecule yields approximately 30–32 ATP through glycolysis (2), the Krebs cycle (2), and oxidative phosphorylation (26–28). Compare this with anaerobic fermentation, which yields only 2 ATP.
07 — Test Your Knowledge

Knowledge Check

20 questions covering cell organelles and energy metabolism. See how much you've learned!