Through a systematic flow of potassium,calcium and sodium ions. Ie. slower acting gates alow timed flow of these ions while a contraction of these cells pushes out ions to restart the resting membrane potiential.
acetyl choline
Diffusion and osmosis differ because diffusion is the process by which molecules spread out, or move from areas with high concentration to low concentration, and osmosis is the diffusion of water. Osmosis is a type of diffusion relating to water. It is usually used to describe the diffusion of water across a membrane (such as the cell membrane). Osmosis is also defined as the flow of solvent from a region of higher pressure toward a region of low pressure.
Because of facilitated diffusion(, which nutralizes it from a higher to a lower concentration.)
Ion moving against a concentration gradient
It is a selectively permeable membrane that allows certain substances in and out, but keeps harmful substances from entering the cell. It could be compared to the security guard at the door of an airport that makes sure that nobody dangerous gets in or out.
Movement of solutes across a lipid bilayer plasma membrane can occur in many ways:1. Osmosis: diffusion of water across membranes to balance solute concentrations.- No energy req- Water passes through membrane via aquaporins, pores in the membrane permeable only to water.2. Simple diffusion: diffusion of only small, hydrophobic (nonpolar) molecules across a membrane down their concentration gradient.- No energy req- Only moves small nonpolar molecules down their concentration gradient3. Facilitated diffusion (passive transport): uses transmembrane protein transporters (channels and carriers) to move polar molecules (ions) across a membrane- No energy required- Channel proteins: Allow for rapid diffusion of specific ions down their concentration gradient- Can be activated by:- Voltage- Ligand- Mechanical force- Carrier proteins: Allow for selective diffusion of specific ions down their concentration gradient.- Uniport carriers: only transport one specific ion down its concentration gradient- Symport carriers: move two different types of ions in the same direction.- Antiport carriers: moves two different ions in opposite directions-Can use the energy created moving one molecule down its concentration gradient to move an ion against its concentration gradient- Carrier proteins exhibit saturation, competition, and specificity.4. Active transport: transport of solutes across a membrane against their concentration gradient.- ATP req- Uses carrier proteins- Leads to creation of potential energy stored in electrochemical gradients
Depolarization
Diffusion across a cell membrane occurs when concentrations of a substance are higher either inside or outside the cell.
Movement across a membrane that does require energy is called active transport.
Active Transport
Yes. Positive ions (sodium) move across the membrane.
Diffusion is what carries materials across the plasma membrane. The diffusion cannot be moved across water.
Diffusion is the movement of ions and other micro molecules across a barrier or membrane. Diffusion is caused by gradients on either side of the membrane.
Diffusion of water across a semipermeable membrane is a type of simple diffusion given the special name of osmosis.
Osmosis
OSMOSIS
Facilitated diffusion is the movement a substance from high concentration to low concentration across a membrane through a transporter protein or channel
Osmosis is the diffusion of water through a semi-permeable membrane, such as that surrounding a cell. Semipermeable indicates that the membrane will allow certain thing to pass through it while preventing others.