In order for cells to survive, they require nutrients in the form of glucose and minerals plus oxygen. Additionally, they need to dispose of waste products. Cells also rely on their organelles and diffusion for survival.
Without oxygen, minerals and the removal of waste products, cells do not survive. In animals, blood delivers the necessary nutrients and oxygen as well as carries away waste. These processes rely on a mechanism called diffusion, which allows substances to pass from one side of the cell wall to the other. Diffusion occurs when the concentration of a substance is higher on one side of the cell wall than the other, causing the substance to move to the side with a lower concentration. The cell membrane acts as a barrier that allows certain substances to pass in and out via diffusion while preventing harmful elements from passing through.
As animals need oxygen to drive their cells' metabolic processes, it is central to cell survival. Without oxygen, cells are not able to transform nutrients into a usable form of energy called ATP. Once ATP is present, the cell performs its functions, which may mean producing a hormone, contracting or forming antibodies. Inside each cell are organelles, which govern these processes and ensure the cell stays alive.