Search results
Results From The WOW.Com Content Network
Because energy is required in this process, it is known as 'active' transport. Examples of active transport include the transportation of sodium out of the cell and potassium into the cell by the sodium-potassium pump. Active transport often takes place in the internal lining of the small intestine.
There are two types of active transport, primary active transport and secondary active transport. [citation needed] Primary active transport uses adenosine triphosphate (ATP) to move specific molecules and solutes against its concentration gradient. Examples of molecules that follow this process are potassium K +, sodium Na +, and calcium Ca 2+.
The sodium–potassium pump (a type of P-type ATPase) is found in many cell (plasma) membranes and is an example of primary active transport.Powered by ATP, the pump moves sodium and potassium ions in opposite directions, each against its concentration gradient.
Passive diffusion across a cell membrane.. Passive transport is a type of membrane transport that does not require energy to move substances across cell membranes. [1] [2] Instead of using cellular energy, like active transport, [3] passive transport relies on the second law of thermodynamics to drive the movement of substances across cell membranes.
As an active transport mechanism, exocytosis requires the use of energy to transport material. Exocytosis and its counterpart, endocytosis, are used by all cells because most chemical substances important to them are large polar molecules that cannot pass through the hydrophobic portion of the cell membrane by passive means. Exocytosis is the ...
A comparison of transport proteins [1]. An antiporter (also called exchanger or counter-transporter) is an integral membrane protein that uses secondary active transport to move two or more molecules in opposite directions across a phospholipid membrane.
The two main pathways are passive transport and active transport. Passive transport is more direct and does not require the use of the cell's energy. It relies on an area that maintains a high-to-low concentration gradient. Active transport uses adenosine triphosphate (ATP) to transport a substance that moves against its concentration gradient.
Diffusion vs. Transport. In biology, an ion transporter is a transmembrane protein that moves ions (or other small molecules) across a biological membrane to accomplish many different biological functions, including cellular communication, maintaining homeostasis, energy production, etc. [1] There are different types of transporters including pumps, uniporters, antiporters, and symporters.