Active Transport
this paragraph is about active transport and all of its specified categories. the movement of ions or molecules across a cell membrane into a region of higher concentration, assisted by enzymes and requiring energy. An example would be someone pushing a large boulder up a hill. this requires energy because of the force needed to push it up the hill. there are two different types of active transport they are endocytosis and exocytosis. Endocytosis is a form of active transport that transports molecules into the cell. A good way to remember this is endo and how the word closely sounds like the word into. it would be like into the cell or "endo" the cell. Exocytosis transports molecules outside of the cell. you can remember this because it sounds like exit. like exit the cell or "exo" the cell. In 1848, the German physiologist Emil Heinrich du Bois Reymond suggested the possibility of active transport of substances across membranes. then, Rosenberg in 1948 formulated the concept of active transport based on energetic considerations,[3] but later it would be redefined. the specialized transmembrane proteins recognize the substance and allow it to move across the membrane when it otherwise would not, either because the phospholipid bilayer of the membrane is impermeable to the substance moved or because the substance is moved against the direction of its concentration gradient.