Many of today's crew-cab pickups have the same legroom as a luxury sedan, and even shoppers who don't go for a crew cab will find that many extended-cab trucks have more passenger room than you'd need under usual circumstances.
n. The protein in the red blood cells of vertebrates that carries oxygen from the lungs to tissues and that consists of four polypeptide subunits, each of which is bound to an iron-containing heme molecule.[Ultimately short for. : hematin + globulin .].. The protein in the red blood cells of vertebrates that carries oxygen from the lungs to tissues and that consists of four polypeptide subunits, each of which is bound to an iron-containing heme molecule. [Ultimately short for.
In vertebrates, these molecules are the proteins myoglobin and hemoglobin. Red blood cells (above) contain hemoglobin. Blood is bright red (left), due the presence of oxy-hemoglobin. Hemoglobin (or haemoglobin, frequently abbreviated as Hb), which is contained in red blood cells, serves as the oxygen carrier in blood.he iron atom in heme binds to the 4 nitrogen atoms in the centre of the porphyrin ring, but this leaves two free bonding sites for the iron, one on either side of the heme plane. The heme group is located in a crevice in the myoglobin molecule, surrounded by non-polar residues except for two polar histidines.