Question

What macromolecules make up the cell membrane?

Answer 1

Hint: A macromolecule, such as a protein, is a very large molecule. They are made up of thousands of atoms that are covalently bonded. Many macromolecules are made up of smaller molecules called monomers that have been polymerized.

Complete answer:
The key ingredients of a cell membrane are phospholipids, proteins, and carbohydrate groups which help to form the cell membrane. Membranes are represented as a fluid lipid bilayer with floating proteins and carbohydrates in the Fluid Mosaic Model.

Lipids (phospholipids and cholesterol), fats, and carbohydrate groups bound to each of the lipids and proteins are the main components of the plasma membrane.

Glycerol, two fatty acid tails, and a phosphate-linked head group make up a phospholipid. A phospholipid bilayer is made up of two layers of phospholipids with their tails pointed inward, as is common in biological membranes. Cholesterol, a lipid with four bonded carbon loops, is present in the membrane's nucleus alongside phospholipids.

Membrane proteins may stretch partially through the plasma membrane, cross the membrane completely, or be loosely attached to the inside or outside face of the membrane.

Carbohydrate groups are only located on the plasma membrane's outer surface and are bound to proteins or lipids to form glycoproteins or glycolipids. Carbohydrates serve as cell adhesion and anchor loci.

Different kinds of cells have different concentrations of proteins, lipids, and carbohydrates in their plasma membranes. Proteins make up about half of a normal human cell's bulk, lipids (of all kinds) make up about 40%, and carbohydrates make up the remaining 10%.

Note:
- The fluid mosaic model, which is now the accepted model for the configuration of the plasma membrane, was first suggested in 1972.
- While this model has changed over time, it still offers a clear general explanation of membrane structure and action in many cells.
- In general, increasing the temperature increases the permeability of the membrane. Since the phospholipids in the membrane don't have any energy at temperatures below 0 oC, they can't shift far, resulting in a tightly packed membrane.