Another method by which a cell can uptake material from the extracellular environment is via a process known as endocytosis. Now, endocytosis requires energy and it's the process by which the cell membrane invaginates and engulfs the material found outside that cell. Now, there are three different processes of endocytosis. We have pinocytosis, thygocytosis and receptor mediated endocytosis. Let's begin with the most common type of endocytotic process known as pinocytosis. Now, Pinocytosis takes place virtually in every single cell and it's the process by which our cell membrane invaginates and engulfs a relatively small quantity of the extracellular fluid.