1. Cell Structure

The Plasma Membrane

Both prokaryotic and eukaryotic cells have a plasma membrane in the figure a phospholipid bilayer with embedded proteins that separates the internal contents of the cell from its surrounding environment. A phospholipid is a lipid molecule with two fatty acid chains and a phosphate-containing group.

The plasma membrane controls the passage of organic molecules, ions, water, and oxygen into and out of the cell. Wastes (such as carbon dioxide and ammonia) also leave the cell by passing through the plasma membrane.  The plasma membrane are semi-permeable and allow small and/or non-polar molecules to pass through. Water, being small, can pass through the membrane and will move from an area of low solute concentration to an area of high solute concentration by the process of osmosis.

A plasma membrane with phospholipid bilayer, proteins, and cytoskeleton labeled.
The eukaryotic plasma membrane is a phospholipid bilayer with proteins and cholesterol embedded in it.

Leave a Reply

Your email address will not be published. Required fields are marked *