The blood of a person contains too little of a component X. The function of X is to carry oxygen in the body. The mineral Y is necessary for the formation of X. The lesser amount of X in the blood due to the deficiency of mineral Y causes a disease Z. (a)What is the component X? (b)What type of blood cells contain X? (c)Name the mineral Y. (d)Name two food items which contain mineral Y? (e)What is disease Z ? Write one symptom of disease?
Answers
Iron
Iron is a trace mineral that we need small quantities every day. It is slightly water soluble and is a cation that exists in two states, +2 (ferrous) or +3 (ferric). Red blood cells contain the oxygen carrier protein hemoglobin. It is composed of four globular peptides, each containing a heme complex. In the center of each heme, lies iron (Figure 10.4.2). Eighty percent of the body's iron is bound to hemoglobin. In the muscle, iron is part of the oxygen-binding protein, myoglobin. Iron is a key component of hundreds of metabolic enzymes. Many of the proteins of the electron transport chain contain iron–sulfur clusters involved in the transfer of high-energy electrons and ultimately ATP synthesis. Iron is also involved in numerous metabolic reactions that take place mainly in the liver and detoxify harmful substances. Moreover, iron is required for DNA synthesis. The great majority of iron used in the body is that recycled from the continuous breakdown of red blood cells.