Oxygen–hemoglobin dissociation curve the fluid that surrounds it. Hemoglobin (Hb) is the primary vehicle for transporting oxygen in the blood. Oxygen is also carried dissolved in the blood's plasma, but to a much lesser degree. Hemoglobin is contained in red blood cells. Under certain conditions, oxygen bound to the hemoglobin is released into the blood's plasma and absorbed into the tissues. Each hemoglobin molecule has the capacity to carry four oxygen molecules. These molecules of oxygen bind to the iron of the Heme group. The binding of the first oxygen molecule induces a conformational change of hemoglobin that increases the affinity for the
Composition of the human body organisms. Composition of the human body Body composition may be analyzed in terms of molecular type e.g., water, protein, connective tissue, fats (or lipids), hydroxylapatite (in bones), carbohydrates (such as glycogen and glucose) and DNA. In terms of tissue type, the body may be analyzed into water, fat, muscle, bone, etc. In terms of cell type, the body contains hundreds of different types of cells, but notably, the largest "number" of cells contained in a human body (though not the largest mass of cells) are not human cells, but bacteria residing in the normal human gastrointestinal tract. Almost 99% of