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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.
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∙ 13y ago
Wiki User
∙ 11y agoacetyl choline
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How do diffusion and osmosis differ from one another?
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.
Why isnt cellular energy required for the passenger molecule to be carried across the cell membrane by the carrier molecule?
Because of facilitated diffusion(, which nutralizes it from a higher to a lower concentration.)
Which of the following required the most ATP to move the molecule across a plasma membrane?
Ion moving against a concentration gradient
Movement across the cell membrane made possible by a protein embedded in the cell membrane?
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.
How do molecules diffuse?
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
What is a shift in the electrical potential across a plasma membrane toward 0mv?
Depolarization
When does diffusion occur across a cell membrane?
Diffusion across a cell membrane occurs when concentrations of a substance are higher either inside or outside the cell.
What motion of particles across a membrane requires energy?
Movement across a membrane that does require energy is called active transport.
What is the process that utilizes a carrier to move materials across the plasma membrane in the direction of the concentration gradient that does not use ATP?
Active Transport
During depolarization does the neurons membrane become negative?
Yes. Positive ions (sodium) move across the membrane.
What is the process that utilizes a carrier to move marerials across the plasma membrane in the direction of the concentration?
Diffusion is what carries materials across the plasma membrane. The diffusion cannot be moved across water.
What drives diffusion?
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.
What is the diffusion of water across the semipermeable?
Diffusion of water across a semipermeable membrane is a type of simple diffusion given the special name of osmosis.
What is the diffusion of water molicules across a membrane?
Osmosis
What is the diffusion of water across a preamble membrane?
OSMOSIS
What is facilitated diffusion across the phospholipid membrane?
Facilitated diffusion is the movement a substance from high concentration to low concentration across a membrane through a transporter protein or channel
Diffusion of solvent particles across a semipermeable membrane?
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.
