Active Transport definition: movement of materials across a membrane that requires an input of energy from a cell.
Active transport of ions across the nerve cell membrane maintains a cell's resting potential. Even at rest, nerve cell membranes have an electrical potential-that is, the interior of a nerve cell has a negative electrical charge relative to the cell's external environment, which is positive.
The electrical potential that exists in a nerve cell membrane when it is at rest is called a resting potential. That resting potential is maintained by an active transport mechanism called the sodium-potassium pump. The sodium-potassium pump is a series of proteins embedded in the cell's membrane. It uses the energy of ATP to move sodium ions -NaK- out of the cell and potassium ions -KK- into the cell.
When a flash of energy is required to move materials through a cell membrane, it is called active transport. The cell membrane helps an organism respond to its environment. Cell membranes are key structures that help organisms maintain homeostasis.
Active transport helps a nerve cell maintain its resting potential through depolarization of cell membrane.
An action potential, according to physiology, takes place when the membrane potential of cell situation abruptly falls and rises. This causes depolarization which then results in depolarization to the adjacent cells. Action potential occur in many cells of animal cells which involve endocrine cells, muscle cells, and glomus cells.
It is accelerated by the special kinds of voltage-gated ion channels which are present within the plasma membrane of the cell. These channels slam when the potential is close to the negative resting potential of the cell, however, they immediately start to activate if the membrane potential rise to a closely defined threshold voltage. This causes depolarization of the transmembrane potential.
When these channels open, they permit the sodium ions to flow inside and cause a change in the electrochemical gradient that in turn generates an elevation in the membrane potential. This then results in more channels to open and thereby, generating a higher electric current through the cell membrane. The movement of sodium ions inside the cell causes a change in membrane polarity and also inactivates the channels. As these channels close, the sodium ions do not transfer inside the neuron.
Action potentials, in the neuron, play an essential function in cell communication by supplying for or with respect to the saltatory conduction. Action potentials are known as nerve impulses in neurons and are generated by a spike train. A neuron which releases the action potential is known as fire.
1.Learn more about cellular respiration
2.Learn more about diffusion
3.Learn more about phospholipid bilayer
Grade: High School
Chapter: Membrane Potentials
Action potential, ions, sodium ions, potassium ions, hyperpolarization, depolarization, neurons, nerve impulse, spike train.