Amembrane is a thin soft layer of material. A membrane separates two things.
Inbiology a membrane can mean two things: a tissue membrane or the membranes of acell. The membranes of cells are very small, while tissue membranes are larger.
A membrane can mean a thin layer ofcells ortissue. This layer covers the body or an organ, or separates, or lines a bodycavity. An example is themucous membrane that is theskin that lines the inside of your nose and mouth. An epithelial membrane has two parts, one part isepithelial tissue and the other isconnective tissue.
There are many different types of membranes in a cell. Thecell membrane, also called the plasma membrane, covers one cell. Membranes also divide the cell into different spaces calledorganelles. Organelles are special areas of the cell that do different work. For example, thenucleus holds theDNA in a cell. Themitochondria makeenergy for the cell.
Membranes in cells are made oflipids (fats) andprotein. The lipids keep the inside of the cell or the organelle separate from the outside. The proteins do many things. Plasma membranes give the cell messages from outside. They let some things (likeglucose,calcium, andpotassium) go into and out of the cell.
