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.
What Cellular Respiration is. Cellular Respiration is the process where living organisms gathers the energy in food molecules to make energy. Heterotrophs, organisms that must get energy from food indirectly from sunlight or inorganic substances, go through the process of cellular respiration to get the energy needed. This energy comes from food. Heterotrophs, including humans and other animals, undergo Cellular Respiration, where the energy contained in food is released to make ATP, which provides cells with the energy needed to carry out the processes of life. Cellular Respiration takes place in a living body of a heterotroph.