Khan Academy Static

Prokaryotic_and_eukaryotic_cells

Here's a question: what's the difference between you and a bacterium? Probably quite a lot of things! At the cellular level, though, some of the key differences include a cell nucleus and membrane-bound organelles, which you have (and the bacterium lacks). Here, we'll look in detail at the differences between prokaryotes and eukaryotes.

Introduction_to_cells

Start your cellular journey the right way: with some history and some microscopy! Here, we'll learn more about how cells were discovered, how they can be observed, and how big they are in comparison to other very small things.

Skill_check_Structure_of_a_cell

Test your understanding of cell structure!

Tour_of_a_eukaryotic_cell

Join us on a voyage through some of the specialized compartments and structures of eukaryotic cells. From the rolling folds of the endoplasmic reticulum to the majestic fibers of the microtubule cytoskeleton, it's a trip you won't regret!

Extracellular_structures_and_cell_cell_junctions

We've spent a lot of time looking at what's inside a cell. But what about the stuff on the outside? Here, we'll look at the extracellular matrix of animal cells and the cell wall of plant cells, as well as the junctions that hold cells together.