do membrane channels require energy?
160261
Channel proteins are simply that: channels. Like a straw, or the drain on a tub, they simply allow water and ions to pass through them. While they can be gated or non-gated, they do not need energy to operate, but neither do uniporters nor other carrier proteins.
1239288
Leak channels, also called passive channels, are always open, allowing the passage of sodium ions (Na ) and potassium ions (K ) across the membrane to maintain the resting membrane potential of –70 millivolts. Voltage-gated ion channels open and close in response to specific changes in the membrane potential.
114781
Every time a pair of high-energy electrons moves down the Electron Transport Chain, the energy is used to move Hydrogen Ions across the Membrane. These Ions then rush back across the Membrane with enough force to spin the ATP Synthase and generate enormous amounts of ATP.
672153
Ligand-Gated Ion Channels. ... Whereas the voltage-gated ion channels underlying the action potential typically allow only one type of ion to permeate, channels activated by extracellular ligands are usually less selective, allowing two or more types of ions to pass through the channel pore.
716164
A. Simple diffusion does not require energy: facilitated diffusion requires a source of ATP. Simple diffusion can only move material in the direction of a concentration gradient; facilitated diffusion moves materials with and against a concentration gradient.
1292368
In the mitochondrion, there are inner foldings called Mitochondrial cristae which help to greatly increase the surface area and lead to a faster production of ATP because there are more places to perform the processes and produce more ATP. Thus more energy will be released.
808919
Although smooth muscle contraction relies on the presence of Ca++ ions, smooth muscle fibers have a much smaller diameter than skeletal muscle cells. T-tubules are not required to reach the interior of the cell and therefore not necessary to transmit an action potential deep into the fiber.
751330
Known as the “powerhouses of the cell,” mitochondria produce the energy necessary for the cell's survival and functioning. Through a series of chemical reactions, mitochondria break down glucose into an energy molecule known as adenosine triphosphate (ATP), which is used to fuel various other cellular processes.
161732
ATP provides the energy for both energy-consuming endergonic reactions and energy-releasing exergonic reactions, which require a small input of activation energy. When the chemical bonds within ATP are broken, energy is released and can be harnessed for cellular work.
1462194
What is the difference between Active Transport and Passive Transport? Active transport requires energy; passive transport does not. The cell membrane is semi-permeable.
312761
What characteristic do simple diffusion and facilitated diffusion share? Both require cellular energy for the transport of substances. Both move water across a semipermeable membrane. substances across the membrane.
1030911
Unlike sodium channels, which primarily initiate action potentials, Ca2+ channels have diverse roles in cells because they both contribute to electrical events during action potential generation and conduction at the cell surface and conduct Ca2+ into the cell to serve as a chemical messenger and initiate many ...
1426602
No. The cell membrane is permeable to hydrophobic molecules. ATP is very hydrophilic. Channels in the cell membrane allow charged particles like Na and K ions to cross.
1248434
In the open state, voltage-gated sodium channels form a pore in the cytoplasmic membrane that allows sodium ions to flow into the cell, depolarizing the cell and generating the upstroke of the action potential; however, most sodium channels rapidly transit into the “inactivated” state at depolarized potentials.
214525
ATP is able to power cellular processes by transferring a phosphate group to another molecule (a process called phosphorylation). This transfer is carried out by special enzymes that couple the release of energy from ATP to cellular activities that require energy.
282504
ATP supplies the energy for muscle contraction to take place. In addition to its direct role in the cross-bridge cycle, ATP also provides the energy for the active-transport Ca++ pumps in the SR. Muscle contraction does not occur without sufficient amounts of ATP.
432966
The electron transport chain is a cluster of proteins that transfer electrons through a membrane within mitochondria to form a gradient of protons that drives the creation of adenosine triphosphate (ATP). ATP is used by the cell as the energy for metabolic processes for cellular functions.