Cell Biology looks at cell's structure, function and chemistry.
Osmosis is the diffusion of water through a partially permeable membrane. Osmosis is especially important in plant; where it is used to regulate the turgidity of cells. They become flaccid when loosing water and turgid when gaining. See Osmosis
Gas exchange depends on the surface area to volume ratio, this influences transport systems. Gas exchange occurs in fish with their gills - water is passed over the lamellae and oxygen is extracted from it. See Gas Exchange
The cell membrane is a phospholipid bilayer with imbedded proteins. Substances can travel across the membrane by diffusion, osmosis or active transport; the proteins in the membrane are often responsible in these processes. See Cell Transport
The eukaryotic cell consists of many different organelles, including the nucleus, mitochondrion, endoplasmic reticulum and golgi body. Endosymbiosis is a theory that explains the origins of organelles in eukarotic cells. See Cell Structure
The cell cycle is the life of a cell: interphase (rest, replication and growth), mitosis (prophase, metaphase, anaphase, telophase) and cytokinesis (splitting). Follow the different stages of the chromosome. See Cell Cycle
Different components of cells can be seen using the electron microscope which is very powerful. Differential centrifugation is a process that breaks open a cell and it is homogenised and centrifuged. See Analysing Cells