Great simulation that shows the VSEPR structures of molecules. It allows you to rotate the molecules to get a better view. Be careful with the bond angles of the models, but the bond angles of the real molecules are correct.
Do your students fully understand how a plant cell is organized and how it operates? Let them interact with an online model, learning about the nucleus, the endoplasm and cytoskeleton, centrosomes and lysosomes, mitochondrion, chloroplasts, and plant cell anatomy and functions. Key words can be added to student vocabulary for a comprehension test; be sure to have them draw and label their own models as well.
/animcell.htm gives the animal cell version.