Nos.: For Out-patient Concerns â MMC Trunk line: (0632)8888-999 local 7330 / Direct line (0632)893-6064 / Grandstream: local (0632)908-6900 local 1375. For In-patient Concerns â MMC Trunkline (0632)8888-999 local 7331. Hours: 7AM â 7PM Mondays to Fridays, Saturday 7AM â 4PM. (CLOSED DURING SUNDAYS AND HOLIDAYS).
The Heme Group. In hemoglobin, each subunit contains a heme group, which is displayed using the ball-and-stick representation in Figure 2. Each heme group contains an iron atom that is able to bind to one oxygen (O 2) molecule. Therefore, each hemoglobin protein can bind four oxygen molecules. One of the most important classes of chelating agents in nature are the porphyrins.
When oxygen binds to at least one of the heme groups (as happens in the oxygen-rich lungs), all of the heme groups become exposed to the environment and bind oxygen easily. The bond between oxygen and heme is a loose one, however, so that the oxygen can break free in the tissues, where the concentration of oxygen is relatively low, and thereby become available for use in the cells.