What is the basic mechanism of active transport in cells?

Active transport in cells involves the movement of molecules across a cell membrane from a lower to a higher concentration using energy.

Active transport is a crucial process that allows cells to maintain their internal environment, different from the external one. This process is carried out by specific proteins embedded in the cell membrane, known as transport proteins or pumps. These proteins use energy, typically derived from ATP (adenosine triphosphate), to move molecules or ions against their concentration gradient, i.e., from an area of lower concentration to an area of higher concentration.

There are two types of active transport: primary and secondary. Primary active transport directly uses energy to transport molecules across a membrane, while secondary active transport involves the use of an electrochemical gradient. In primary active transport, the energy is used to change the shape of the transport protein, which allows the molecule to be moved across the membrane. An example of this is the sodium-potassium pump, which is vital for nerve function.

Secondary active transport, on the other hand, uses the energy stored in the form of an electrochemical gradient, created by primary active transport. This gradient drives the movement of other molecules against their own concentration gradients. An example of this is the glucose transporter found in the intestines and kidneys.

In summary, active transport is a vital cellular process that uses energy to move molecules against their concentration gradient. This process is facilitated by transport proteins and is essential for maintaining the cell's internal environment.