Phospholipids

Phospholipids are a class of lipids that are major components of all cell membranes. They are amphipathic molecules, meaning they have both hydrophilic (water-attracting) and hydrophobic (water-repelling) regions.

Structure of Phospholipids:

A typical phospholipid molecule consists of a hydrophilic head and two hydrophobic tails. The head is composed of a phosphate group and a glycerol molecule, while the tails are usually two fatty acid chains.

Function of Phospholipids:

Phospholipids play a crucial role in the structure and function of cell membranes. They form a lipid bilayer, with the hydrophilic heads facing the aqueous environment and the hydrophobic tails facing inward, creating a barrier that separates the inside of the cell from the outside.

Phospholipid Bilayer:

The arrangement of phospholipids in a bilayer is vital for the selective permeability of cell membranes. This allows the cell to control the passage of substances in and out of the cell.

Study Guide:

1. Describe the structure of a phospholipid molecule.
2. Explain the amphipathic nature of phospholipids.
3. Discuss the role of phospholipids in cell membranes.
4. Explain the significance of the phospholipid bilayer in cell membrane structure and function.
5. Compare and contrast the functions of the hydrophilic head and the hydrophobic tails of phospholipids.