Phenylketonuria (PKU) can be defined as a rare metabolic disorder caused by a deficiency in the production of the hepatic (liver) enzyme phenylalanine hydroxylase (PAH). PKU is the most serious form of a class of diseases referred to as hyperphenylalaninemia, all of which involve above normal (elevated) levels of phenylalanine in the blood.
All organisms carry out cellular respiration (except viruses) - it is the basic process which supports life as we know it. Viruses, on the other hand, are not always câ¦onsidered to be living, one of the reasons being that they do NOT carry out cellular respiration.
Cellular respiration, also termed as internal respiration, occurs in living cells. The oxygenated blood is carried to all living cells in the body of an organism through blood circulatory. Cellular respiration involves breakdown of glucose into carbon dioxide and water in presence of oxygen, releasing energy. Oxygen carried by blood is used in cellular respiration and carbon dioxide released combines with hemoglobin in RBCs. Deoxygenated or impure blood is carried by veins to the lungs to be converted into oxygenated blood.