Actually the haemoglobin molecule consists of 2 parts, the haem which is a prosthetic group and the other globin which is a protein. So the haemoglobin as is a protein so, is arranged in quaternary structure of protein which contains 4 subunits. The subunits depend upon the organism whose haemoglobin is being talked about. So the normal haemoglobin found in red blood cells contains 2 alpha subunits + 2 beta subunits. At the centre of each subunit there is the haem part attached. To the centre of haem the Fe3+ ion are present which actually attaches to 1 Oxygen molecule. So as 4 subunits are present and each subunit has 1 Fe3+ ion, so total 4 Oxygen molecules can bind to the 1 Hb molecule!!
el niño tendría síndrome de downEl síndrome de Down es causado por un error aleatorio en la división de las células que tiene como resultado la presencia de una copia extra del cromosoma 21.
<span>Which term refers to the process by which individuals that are better adapted to their environment are more likely to survive and reproduce? The correct answer is A. natural selection. </span>
