Cell Transport
The purpose of cell transport is to maintain homeostasis. The different kinds of cell transport are divided into two categories: those that require energy and those that do not.
Passive transport does not require energy. There are three kinds of passive transport. In diffusion substances move from high concentrations to low concentrations. In facilitated diffusion substances move from high concentrations to low concentrations via carrier proteins. Finally, in osmosis water moves from high concentrations (of water) to low concentrations.
Active transport requires energy and usually moves substances from low concentrations to high concentrations against the concentration gradient. In endocytosis, a form of active transport, the cell engulfs material. In exocytosis, the cell expells material.
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