Final answer:
Active transport is the process where molecules are moved against the concentration gradient utilizing energy, often from ATP, through membrane proteins like the sodium-potassium pump.
Step-by-step explanation:
The transport process that involves the movement of molecules against the concentration gradient is known as active transport. This process requires energy because substances are being moved from an area of low concentration to an area of high concentration, which is contrary to their natural diffusion path. The most common source of energy for active transport is ATP, which helps power the transport mechanisms, such as the well-known sodium-potassium pump.
Active transport is critical for maintaining homeostasis within a cell by controlling the internal composition regardless of the external conditions. It employs membrane proteins to move substances like ions and molecules effectively against their concentration gradients. For example, this process is utilized to pump sodium out of the cells and potassium into the cells in our body.