Answer to Question #61099 in Chemistry for Amit Sharma

Question

What are the various constituents of cell membrane? Describe the modes by which cell membrane
controls the transport of ingoing and outgoing molecules.

Answer 1

Cell membrane is a biological membrane which separates the interior of cells from the outside environment. They contain a variety of biological molecules, mainly lipids and proteins.
There are several ways of transport through membrane:
- Passive osmosis and diffusion: small molecules, ions, carbon dioxide and oxygen can move across plasma membrane by diffusion which is a passive transport process;
- Nutrients (sugars, amino acids) are being transported through membrane by transmembrane protein channels and transporters;
- Another cells are transported by endocytosis – the process in which cells absorb molecules by engulphing them;
- A process in which membrane of a vesicle can be fused with the plasma membrane extruding its components to the surrounding medium is called exocytosis.