MEDICAL PHYSIOLOGY

Detailed explanation-1: -To move substances against a concentration or electrochemical gradient, a cell must use energy. Active transport mechanisms do just this, expending energy (often in the form of ATP) to maintain the right concentrations of ions and molecules in living cells.

Detailed explanation-2: -ATP plays a critical role in the transport of macromolecules such as proteins and lipids into and out of the cell. The hydrolysis of ATP provides the required energy for active transport mechanisms to carry such molecules across a concentration gradient.

Detailed explanation-3: -During active transport, a protein pump uses energy, in the form of ATP, to move molecules from an area of low concentration to an area of high concentration. An example of active transport is the sodium-potassium pump, which moves sodium ions to the outside of the cell and potassium ions to the inside of the cell.

Detailed explanation-4: -Molecules of ATP bind to proteins in the cell membrane, causing them to change their shape. The conformational changes of many proteins together change the shape of the cell membrane until a vesicle is created.

Detailed explanation-5: -Active transport is a process that is required to move molecules against a concentration gradient. The process requires energy. Energy for the process is acquired from the breakdown of glucose using oxygen in aerobic respiration. ATP is produced during respiration and releases the energy for active transport.