Membranes

What do phospholipids make up in a cell?

The cell membrane.

What are the components of a phospholipid?

Each phospholipid consists of a phosphate head linked to 2 fatty acid chains.

What is the relationship between the phosphate head of a phospholipid and water?

They interact because the phosphate head is hydrophilic

Describe the nature of the fatty acid tails in phospholipids.

The tails are hydrophobic.

What do phospholipids create?

Two layers which make the cell’s double membrane

What structure do phospholipids form in water?

A continuous sheet-like bilayer in water.

Where are phospholipids synthesized in the cell?

Phospholipids are synthesized by the smooth endoplasmic reticulum (smooth ER).

How are phospholipids transported to the cell membrane?

Phospholipids are transported as vesicles to the cell membrane.

What is the permeability of membranes?

Low.

What benefit does low permeability provide to cells?

It allows for the maintenance of a concentration gradient.

What substances are held inside the cell due to low permeability?

Useful substances are held inside, and harmful substances are prevented from entering.

What properties allow phospholipid bilayers to carry out life's processes?

The properties include low permeability and fluidity.