Question

An intracellular signaling molecule produced by the binding of a ligand to a membrane-bound receptor is called a __________.

Answer 1

Answer:

The intracellular molecule produced by the receptor ligand complex is called Second messenger.

Explanation:

Receptors are membrane bound proteins which bind to the ligands which are also called first messengers and cause cellular changes. These intracellular changes are mediated by second messengers such as proliferation, differentiation, migration, apoptosis, transcription, contractions etc. They are specific for specific first messengers such as homones and growth factors. They relay the signals between the ligands to their target molecules in the cytosol or nucleus. Most common second messengers are cAMP, cGMP, DAG, IP3.

Signal amplification by second messenger can be explained by the example of IP3 which cayses the release of Calcium ions from the intracellular stores and cause contractions.

Answer 2

Answer:

An intracellular signaling molecule produced by the binding of a ligand to a membrane-bound receptor is called a second messenger .

Explanation:

The ligands bind to the receptors and produce response by different signalling pathways resulting in the activation of the effectors.

As the ligand bind to the membrane bound receptor , intracellular signalling molecule is produced called a second messenger that relay the signals recieved at the receptor site to the target molecules triggering the physiological changes at the cellular levels.

Most common second messengers include :

1) cyclic GMP

2) cAMP (cyclic AMP )

3) DAG (Diacyl glycerol )

4) ROS (Reactive oxygen species )

5) Ca (Calcium)