A heme group is a prosthetic group composed of a protoporphyrin ring and an iron (Fe) atom that binds to oxygen (O2) in hemoglobin and myoglobin. Hemoglobin (Hb) is a protein in red blood cells (erythrocytes) that carries oxygen from the lungs to the tissues, which is composed of four polypeptide chains, each with a heme group. Moreover, myoglobin is a monomeric protein located mainly in the muscles, which contains one heme group, being thus similar to hemoglobin monomers. The proximal and distal are evolutionarily conserved amino acid (histidine) residues whose names (proximal and distal) refer to their position with the iron (Fe) atom in the heme group. The proximal histidine connects the heme group with the proteins (either in monomeric myoglobin or in one subunit of Hb), whereas distal histidine contributes to stabilize these proteins while carrying O2.
A white blood cell engulfing foreign materials is more likely to carry out Endocytosis.
Explanation:
Endocytosis is the process by which a cell takes up a macromolecule into is cytoplasm by forming a vessicle.
In the question two cases are given, both the cases involve the formation of membrane bound vessicle but in different ways.
The excretion of hormones involves the movement of molecule outside the cytoplasm. This process is exocytosis.
The engulfment of an antigen by WBC involves taking up of molecule within the cell so that it can be killed and digested. Thus in this case Endocytosis is more likely to occur..
They are made of protein and one molecule of deoxyribonucleic acid (DNA). As the genetic material passes from parents to child, the chromosomes are responsible for containing the instructions that make the offspring unique while still carrying traits from the parent.
