The cell is the minimum unit of all living organisms. Each single cell contains all of the information that defines the species, and has the ability to reproduce itself. It requires its selective barrier, the plasma membrane, to not only protect cells from the environment but also concentrate nutrients, which are used to synthesise molecules for the cell function. Eukaryotic cells contain membrane-enclosed compartments, called organelles, each of which has its own specialised function. The nucleus contains the genome and is the primary site of both DNA and RNA synthesis; the endoplasmic reticulum (ER) is a factory that synthesises proteins and lipids, and the mitochondrion produces ATP, the energy currency utilised in many chemical reactions inside the cell.¹  In addition to mitochondria, the chloroplast in the plant cell also produces ATP; other important functions of the chloroplast are the production of O₂ and the assimilation of carbon atoms to sugars, which serve as food, biomass, and fossil fuels.²  The activity of the cell could affect the cellular temperature, as cellular function is supported by numerous chemical reactions, which are either exothermic or endothermic.