Question

How do proteins contribute to the function of the cell membrane?

Answer 1

The cell membrane is a biological membrane that provides structure to the cell by bounding the cell organelle and cytoplasm and separates the interior of all cells from the outside environment which protects the cell from its environment. The cell membrane consists of a lipid bilayer, and also cholesterols that sit between phospholipids to maintain their fluidity at various temperatures.

Complete answer:
The plasma membrane is a semi permeable boundary that separates living cells from surroundings and is made up of lipids and proteins.

The Six major functions of membrane proteins are following:
- Attachment to the cytoskeleton and extracellular matrix.
- Intercellular joining-Proteins on adjacent cells bind together briefly so that cells can interact.
- Signal transduction-Transmission of molecular signals from a cell's exterior to its interior
- Enzymatic activity-When a protein is built into the membrane it may be an enzyme with its active site which are exposed to substances in the adjacent solution.
- Cell-cell recognition-Cell's ability to distinguish one type of cell from another.When some glycoproteins (proteins bonded to short chains of sugars) serve as identification tags that are specifically recognized by other cells.
- Transport-Transport proteins are used in various ways to move substances inside and outside the cell membrane.

Note: The most abundant lipids in plasma membrane contain hydrophilic and hydrophobic regions - phospholipid bilayer.Phospholipids are able to move within the bilayer Membrane. proteins are dispersed and separately inserted into the phospholipid bilayer.