<span>An insulin receptor is a neurotransmitter that is activated by the presence of insulin. This receptor is usually represented by the abbreviation (IR),</span>
It is necessary for the pancreas to secrete a high pH solution into the intestine in order to neutralize the acidity of the processed food particles [chyme] that are passed into the intestine and to provide a suitable pH for the enzymes in the intestines that will act on the processed food particles.
The endosymbiotic hypothesis concerns the origin of mitochondria and chloroplasts, two organelles contained within various eukaryotic cells. According to this hypothesis, these organelles originated as separate prokaryotic organisms that were taken inside a primordial eukaryotic cell.