Short biology/physio question. Please help!?

Question

could anyone write a sentence of two about this?

The Structure of a phospholipid membrane

and

a general description of what happens when a ligand binds to a cell receptor protein?

please help

thanks.

Answer 1

The Structure of a phospholipid membrane

It is fluid phosphlipids are able to move around.   Each phospholipid has a Fatty acid tail which is hydrophobic and a phosphate group which is hydrophilic and able in interact with polar or water loving molecules.

http://www.health.bcu.ac.uk/physiology/p...

a general description of what happens when a ligand binds to a cell receptor protein?

Receptor binds cell protein, the binding causes a confirmational change in the structure of the cell protein, it sends a re-lay signal through secondary signals (ie phosphoyrlation ) which results in a signal cascade the cell transmits usually to the nucleus, which eihter activates or inhibits a process.

Answer 2

The Structure of a phospholipid membrane:

-The phospholipids are arranged in a bilayer because they have a polar heads and non-polar tails. The polar heads are said to be ‘hydrophilic’ (water loving) and so they are exposed to water inside and outside the cell. The non-polar tails are ‘hydrophobic’ (water fearing) and are located on the inside of the membrane so that they are not exposed to the water.  

What happens when a ligand binds to a cell receptor protein?

- The ligand can bind to the receptor protein on the membrane and initiates a reaction or chain of events on the inside of the cell