Final answer:
Cell transport across the cell membrane is an example of maintaining homeostasis. Active transport is a mechanism used to maintain homeostasis by regulating the concentration of molecules or ions inside the cell.
Step-by-step explanation:
Cell transport across the cell membrane is an example of maintaining homeostasis. Homeostasis is the process of maintaining a stable internal environment within the cell. The cell membrane controls the movement of substances in and out of the cell, allowing the cell to maintain the balance of molecules and ions that is necessary for its proper functioning.
One mechanism used to maintain homeostasis is active transport, which requires energy. Active transport is the movement of substances against their concentration gradient, from an area of lower concentration to an area of higher concentration. This process allows the cell to regulate the concentration of certain molecules or ions inside the cell, even when the concentration outside the cell is different.
For example, sodium-potassium pumps in the cell membrane use active transport to maintain the proper balance of sodium and potassium ions inside and outside the cell. The pump transports three sodium ions out of the cell for every two potassium ions it brings into the cell, against their concentration gradients. This helps to maintain the electrical charge and osmotic balance of the cell, which are vital for its functioning and overall homeostasis.