Final answer:
Active transport is the type of carrier mediated transport that moves substances against a concentration gradient using energy, typically in the form of ATP. Carrier proteins, functioning as pumps, enable this 'uphill' movement, exemplified by the sodium-potassium pump in animal cells.
Step-by-step explanation:
The type of carrier mediated transport that requires energy to move substances against a concentration gradient from an area of lower concentration to an area of higher concentration is known as active transport. This energy-intensive process is necessary when a cell needs to transport molecules 'uphill', in contrast to passive methods like diffusion. The cellular energy currency, ATP (adenosine triphosphate), produced through cellular respiration, is often utilized to power active transport systems such as carrier proteins, which function as pumps.
An example of an active transport mechanism is the sodium-potassium pump, which actively exchanges sodium ions for potassium ions across the plasma membrane of animal cells, despite the steep concentration gradient it must work against. These pumps, or carrier proteins, undergo a change in shape when they bind with ATP. This change allows them to move the ions or molecules across the cell membrane, effectively performing the function necessary for various cellular processes.