Iron cannot be transported around the body's circulation system as free iron, since it would be susceptible to chelation by siderophores, or may precipitate as iron(III) oxide, or may form iron(II). Therefore, a specific transport protein is required, called transferrin. (In fact, a whole class of transferrin-like proteins is involved in iron transport.) Transferrin is a medium-sized protein with a relative molecular mass of about 80 000.
Important: Do not reset your ice maker more than one time in a twenty-four hour period. in the ice tray over filling. If the ice tray over fills, water will pour directly into the ice bucket and freeze. the ice bucket is frozen you will not be able to dispense ice.
If the ice cubes are hollow, it indicates there is not enough water entering the ice maker. In this case, the water level adjustment knob should be turned to the left. The knob should only be turned 1/4 of a turn each time so as to not over-adjust. If turning the knob 1/4 of a turn is not enough, try turning the knob another 1/4 of a turn. The maximum adjustment is one full turn in either direction. Additional rotation could damage the ice maker.