What is artificial life?

Artificial life, also known as synthetic life, is life that is created from scratch. In order for it to be considered life, it should have a membrane which is capable of self-assembly and able to form compartments. It should also be able to maintain an ionic gradient across this membrane, which will help protect the cell from its environment. In order to be considered true life however, it must be able to capture and use energy, usually in the form of ATP. Along with this come the necessity to be able to transfer smaller molecules to provide the substrates needed to produce ATP. It should also be able to polymerise these smaller molecules into macromolecules, such as proteins and carbohydrates, that can act as an energy store and be broken down when needed. Artificial life would need to use enzymes to catalyse these biological reactions, since without them the rate of reaction would be too slow and unable to support life. The final key part is the ability to encode its genetic information, which as the cell grows and divides it is then passed on to subsequent generations. With this, there needs to be the potential for occasional mutations so that it can evolve through natural selection. These are considered properties that would of been necessary for the first form of life to emerge, and so should be considered essential criteria in whether considering if something that is synthesised is in fact life.Artificial life can be created in two approaches - the "bottom up" and the "top down" approach. The top down approach involves using techniques like genetic engineering to manipulate already existing cells. Current approaches have focused on creating very small artificial genomes and implanting them into bacteria to assess which genes are essential for life. The bottom up approach involves creating all of these cellular components from scratch. This is a difficult task since it requires understanding of not only the molecular biology of the cell, but has to be pieced together in the correct way in order to properly function. Researches have been able to create cellular components separately, but creation of a purely artificial cell has not yet been achieved.