what is the functionality of the main topic in discussion?
The most prominent roles of mitochondria are to produce the energy currency of the cell, through respiration, and to regulate cellular metabolism.
Mitochondrion
The most prominent roles of mitochondria are to produce the energy currency of the cell, ATP (i.e., phosphorylation of ADP), through respiration, and to regulate cellular metabolism. 
where is the mitochondria located in an animal cell UNANSWERABLE what is the main topic in discussion? Mitochondrion. what is it's structural composition? They contains outer and inner membranes composed of phospholipid bilayers and proteins, that have different properties. Because of this double-membraned organization, there are five distinct parts to a mitochondrion. what does the first membrane mentioned consist of? It contains large numbers of integral membrane proteins called porins. and what does the other membrane consist? It contains more than 151 different polypeptides, and has a very high protein-to-phospholipid ratio.
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Mitochondrion [SEP] Function
The most prominent roles of mitochondria are to produce the energy currency of the cell, ATP (i.e., phosphorylation of ADP), through respiration, and to regulate cellular metabolism. The central set of reactions involved in ATP production are collectively known as the citric acid cycle, or the Krebs cycle. However, the mitochondrion has many other functions in addition to the production of ATP.