Biological complexity: red cell enzyme activity (Introduction)

by David Turell , Monday, May 23, 2016, 15:48 (3106 days ago) @ David Turell

Red cells have no nucleus but have the task of carrying oxygen to the tissues of the body as fuel, and then hauling out CO2 as waste product. The transfer of the gases must be instantaneous, and of course, there is the appropriate enzyme in place:- http://phys.org/news/2016-05-captures-ultrafast-motion-proteins.html-"A new study by an international team of researchers, affiliated with Ulsan National Institute of Science and Technology (UNIST) has announced that they have succeeded for the first time in observing the structural changes in carbonic anhydrase.-*** -"Carbonic anhydrase, which is found within red blood cells, is a crucial enzyme that stabilizes carbon dioxide (CO2 ) concentrations. This enzyme catalyzes a reaction converting CO2 and water into carbonic acid, which associates into protons and bicarbonate ions.-"Moreover, it is also known that carbonic anhydrase is able to catalyze at a rate of 106 reactions per second. In the absence of this catalyst, the conversion from CO2 to bicarbonate, and vice versa, would be extremely slow and difficult.-"One of the important functions of the enzyme in humans is to adjust the acidity of the chemical environment to prevent damage to the body, as well as to help transport carbon dioxide out from tissue cells to the lungs. -***-"Prof. Kim, the lead researcher of the study states, "The reaction rate of carbonic anhydrase is one of the fastest of all enzymes." He continues, "Due to the rapid movement of proteins, direct observation for such movement has been extremely difficult to obtain, protein scientists say.'"-Comment: a movie diagram at the link gives a sense of the speed of the reaction. Usual question: enzymes are huge molecules. How did evolution search for it and get it just right?