L-carnitine. Coloured scanning electron micrograph (SEM) of L-carnitine. This biochemical is responsible for the transport of fatty acids from a cell's cytoplasm into mitochondria, where they are oxidised to produce energy. It can be synthesised in the body from the amino acids lysine and methionine and is also found in many foods including red meat, green vegetables and cereals. Magnification: x230 when printed 10 centimetres wide.