During Active and Passive transport is ATP required?

ATP is required during active transport but is not required during passive transport.

During active transport, ATP is indeed required. Active transport is a process by which molecules or ions are moved across a cell membrane against their concentration gradient, from an area of lower concentration to an area of higher concentration. This process requires energy input, typically in the form of ATP (adenosine triphosphate).

To understand why ATP is necessary for active transport, let's look at the mechanism involved.

1. The transport protein: Active transport relies on specific transport proteins embedded in the cell membrane. These proteins act as pumps, responsible for moving molecules or ions across the membrane.

2. ATP binding: Before any movement can occur, ATP must bind to the transport protein. This binding allows ATP to be hydrolyzed, meaning it is broken down into ADP (adenosine diphosphate) and an inorganic phosphate molecule (Pi). This step itself requires energy.

3. Conformational change: The hydrolysis of ATP induces a conformational change in the transport protein. This change in shape is crucial for its function. It enables the transport protein to grab hold of the molecule or ion to be transported.

4. Transport of solute: The transport protein uses the energy from ATP hydrolysis to move the solute against its concentration gradient. As a result, the transported molecule or ion is pushed from an area of lower concentration to an area of higher concentration.

5. Releasing ADP and Pi: Once the solute has been transported, the transport protein releases ADP and Pi. This allows the transport protein to return to its original shape and be ready for another round of active transport.

Overall, ATP provides the energy necessary to power the active transport process. Without ATP, active transport across the cell membrane would not be possible, and molecules or ions would not be able to move against their concentration gradient.