Tag: Norepinephrine
-
Ferrochelatase catalyses the eighth and terminal step in the biosynthesis of heme, converting protoporphyrin IX into heme B
Protoporphyrin ferrochelatase (EC 4.98.1.1, formerly EC 4.99.1.1, or ferrochelatase; systematic name protoheme ferro-lyase (protoporphyrin-forming)) is an enzyme encoded by the FECH gene in humans. Ferrochelatase catalyses the eighth and terminal step in the biosynthesis of heme, converting protoporphyrin IX into heme B. It catalyses the reaction: protoheme + 2 H+ = protoporphyrin + Fe2+ Function Ferrochelatase catalyzes the insertion of ferrous iron into protoporphyrin IX in the heme biosynthesis…
-
Enkephalins
An enkephalin is a pentapeptide involved in regulating nociception (pain sensation) in the body. The enkephalins are termed endogenous ligands, as they are internally derived and bind to the body’s opioid receptors. Discovered in 1975, two forms of enkephalin have been found, one containing leucine (“leu”), and the other containing methionine (“met”). Both are products of the proenkephalin gene. Endogenous opioid peptides There are three well-characterized families of opioid…
-
Chromaffin cells aka pheochromocytes
Chromaffin cells, also called pheochromocytes (or phaeochromocytes), are neuroendocrine cells found mostly in the medulla of the adrenal glands in mammals. These cells serve a variety of functions such as serving as a response to stress, monitoring carbon dioxide and oxygen concentrations in the body, maintenance of respiration and the regulation of blood pressure. They are in close proximity to pre-synaptic sympathetic ganglia of the sympathetic nervous system,…
-
Pterion and Pteron Notes
The pterion is the region where the frontal, parietal, temporal, and sphenoid bones join. It is located on the side of the skull, just behind the temple. Structure The pterion is located in the temporal fossa, approximately 2.6 cm behind and 1.3 cm above the posterolateral margin of the frontozygomatic suture. It is the junction between four bones: These bones are typically joined by five cranial sutures: Clinical significance Haematoma…