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The cell membrane is made up of a _____ bilayer.

Cell membranes are also described as lipid bilayers. There are two layers of phospholipids with proteins embedded in the layers. The membrane is able to move as needed by the cell.

Cell membranes are firm and rigid structures made with cellulose.

Cell walls are the rigid structures that surround most plant cells. Cell membranes are fluid and able to stretch and move as needed by the cell.

Cell membranes can wrap around large food molecules in a process called

Endocytosis is the process of cell eating. Exocytosis is when a cell sends something out of the cell. Pinocytosis is the process of a cell bringing in liquids like water.

All eukaryotic cells are surrounded by a cell membrane.

Eukaryotic cells have an organized nucleus and cell organelles. All of these cells have a membrane. Plant cells have a cell membrane and cell walls.

Osmosis is a process where _____ crosses the membrane.

Osmosis is a process where water can pass across the cell membrane. The pressure of water on a cell is also called the osmotic pressure of the solution.

Some molecules can pass through a cell membrane without help

Some molecules can pass through the cellular membrane by a process called diffusion. Other molecules are too large to pass through the membrane and must be helped across the lipid bilayer

The heads of the lipids in the cell membrane are

The head end of a phospholipid molecule is hydrophilic. The heads like to be near water and arrange themselves so that tails meet tails and the heads face the cellular fluids and exterior of the cell.

The lipids in the bilayer have tails that are

The tail end of a phospholipid molecule is hydrophobic. The tails do not like to be near water and arrange themselves so that tails meet tails and the heads face the cellular fluids and exterior of the cell.

You will also find proteins in the lipid bilayer

There are proteins embedded in the cell membrane. Some of the proteins pass through the membrane and others are only attached to the surface. The proteins serve several functions

All proteins that are a part of the bilayer cross the cell membrane.

While there are many proteins along the cell membrane, not all of them pass through the membrane. Some cross the membrane (integral) and others just sit on the inner or outer surface (peripheral).