The Characteristics of Cell Membranes for Kids

The Barrier to Keep Bad Things Out

• The cell membrane can be thought of as a clear plastic bag with tiny holes in it. While it holds together the cell's parts, or organelles, it also works to keep bad things on the outside of the cell from entering in. The membrane is made up of proteins and phospholipids and it's the phospholipids that make up the wall barrier of the cell that blocks bad organisms from getting into the cell and harming the cell's organelles.

The Barrier to Keep Good Things In

• While the cell's membrane works as a wall barrier to keep bad organisms out of the cell, it also works as a wall barrier to keep the good organelles inside of the cell. Because each working part of the cell is necessary in order for the cell to function properly, if one organelle fell out of the cell then the entire cell could die. The phospholipids of the membrane hold all of the organelles in place so the cell can function.

Tiny Holes

• The cell membrane has been described as resembling a plastic bag with tiny holes in it. The tiny holes in the membrane are used for transportation. While the cell membrane does keep good parts inside the cell and bad parts out, it is also necessary for the cell to transport molecules and ions through the membrane in order to keep a balance of ions and molecules inside and outside the cell. The proteins in the membrane are used to transport ions and molecules inside and outside the cell.

Cell Eating and Drinking

• The cell membrane is also used when the cell needs to eat or drink. A cell eating is called phagocytosis and a cell drinking is called pinocytosis. The whole cell works together to eat and drink and the membrane's job is to wrap itself around a liquid or solid and then pinch a piece off into the cell. From there, the rest of the cell works to break down the liquid or solid, absorb nutrients and digest.