The process that requires energy provided by ATP is active transport.

Active transport is a process in which molecules or ions move against their concentration gradient, from an area of lower concentration to an area of higher concentration. This movement of substances across the cell membrane requires energy, which is provided by ATP (adenosine triphosphate) through the breakdown of its high-energy phosphate bond.

Explanation:

1. Active transport and ATP:
Active transport is a process that requires the expenditure of energy to move substances across the cell membrane. This energy is provided by ATP, which is often referred to as the "energy currency" of cells. ATP is a molecule that stores and releases energy as needed by cells.

2. ATP breakdown:
When ATP is utilized for active transport, it undergoes hydrolysis, where one of its phosphate groups is cleaved off, resulting in the formation of ADP (adenosine diphosphate) and an inorganic phosphate (Pi). This release of a phosphate group releases energy that can be used by the cell for various cellular processes.

3. Sodium-potassium pump:
One example of active transport is the sodium-potassium pump, which is essential for maintaining the proper balance of ions inside and outside of cells. The sodium-potassium pump actively transports three sodium ions out of the cell and two potassium ions into the cell against their respective concentration gradients. This process requires the hydrolysis of ATP to provide the energy needed to pump these ions across the cell membrane.

4. Other examples of active transport:
In addition to the sodium-potassium pump, there are several other examples of active transport in cells. These include the calcium pump, which actively transports calcium ions against its concentration gradient, and the proton pump, which transports protons across membranes.

5. Importance of active transport:
Active transport is crucial for many physiological processes in living organisms. It allows cells to maintain proper ion concentrations, enables nutrient uptake, facilitates waste removal, and plays a key role in nerve cell signaling. Without active transport, cells would not be able to maintain their internal environment and carry out essential functions.

In summary, active transport is a process that requires energy provided by ATP. ATP is broken down to release energy, which is then used to transport substances across the cell membrane against their concentration gradients. Without ATP and active transport, cells would not be able to maintain proper ion concentrations and carry out essential functions.