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... Only allows certain molecules to pass through the "membrane." Think of the membrane as a one way gate. For example some selectively permeable membranes only allow H2O to pass through the wall in one direction and block other molecules.
Wiki User
∙ 14y ago
Wiki User
∙ 14y agothis means that cell membrane allows only selected substances to enter the cell.
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What is a membrane protein that allows specific charged molecules to pass through from one side of the membrane to another?
A membrane protein that permits the passage of specific substances is selectively permeable. They allow the solvent as specific solutes to pass through.
How is the function of epithelium reflected in its structure?
Since epithelium needs to serve as both a barrier and selectively permeable membrane, the cells need to be tightly junctioned to one another (thus prohibiting paracellular transport) and need to express channels, transporters or exchangers to allow for movement of selected ions/molecules across the epithelial barrier
Why is cell membrane differentially permeable?
Selective (or differential) permeability allows the cell to regulate its internal environment and maintain internal homeostasis. This is also the basis by which a neuron (nerve cell) can 'fire' and send a message along its axon - it selectively allows one electrolyte then a different electrolyte to flow across its cell membrane and change the electrochemical gradient.
What is a selectively permeable membrane and how does it function?
It is a membrane in cells that only allows certain things in. For example a long time ago large and small cats had an epidemic of acquired immune deficiency syndrome (aids). a few cats had cells with selectively permeable membranes that for some reason wouldn't let the aids virus in. Those cats survived and now most cats are resistant to aids.IN ADDITION:Imagine 3 sheets of paper. The first sheet had holes about the size of a golf ball. The second had holes the size of a grape. The third had holes the size of a needle in it. You stack the three together with a space between the three so that these particles can move around a little bit. Now, mash up a whole orange and pour this material on the three membranes. The orange peel can go only as far as the holes will allow it and will stop at the first and may make it to the 2nd sheet. The seeds and pulp will go through the first and second layer but will get stopped by the third. The juice will pass through all three. Another good example is your skin, It allows carbon dioxide and sweat to exit the body but keeps the blood in. It selects what can and cannot pass through its membrane. Some membranes work in one direction only, others allow passage either way. exaclty yay we did it lolAnswerplasma membrane
What will a chamber separated by a semi-permeable membrane with one side containing a mixture of molecules in water and the other side containing only water contain after an extended period of time?
The molecules in the one chamber will diffuse into the other through the semi-permeable membrane so that eventually, both sides will be identical in composition.
What substance can diffuse through a differentially permeable membrane?
Diffusion across a membrane in biology is referred to as 'osmosis' & osmosis is the process by which solvent molecules move from a region of high conc. to low concentration and this can therefore occur only in one direction at a time for a perticular solution. this is a really smart answer im surprised
What is a membrane protein that allows specific charged molecules to pass through from one side of the membrane to another?
A membrane protein that permits the passage of specific substances is selectively permeable. They allow the solvent as specific solutes to pass through.
What types of membrane allow solvent molecules to pass through but do not allow solute molecules to pass through?
A membrane that does not allow substances through is impermeable. One that allows some substances, but not others, is semipermeable or selectively permeable.
What is the diffusion of water molecule through a selectively permeable membrane?
It's called osmosis. A selectively permeable membrane will only allow certain molecules to pass trough. To illustrate: If you have a high concentration of sugar molecules on one side of the membrane, no sugar on the other side, and the sugar molecules are too big to pass trough the membrane. If this is the case, then water molecules will diffuse over to the side of the membrane with a high sugar concentration. This happens because the molecules try to distribute themselves evenly in the solution. The water molecules move because the sugar molecules can't.
On which side of a selectively permeable membrane does osmosis exert pressure?
A selectively permeable membrane (also known as a differentially permeable membrane or a semi-permeable membrane) is permeable to the solvent but not to solutes.In cells, the solvent is always water.All cell membranes (such as plasma membranes and vacuole membranes) are selectively permeable.This means that water can cross these membranes by osmosis. This will happen when the total concentration of solutes on one side of the membrane is different from that on the other side.The process is passive (requiring no energy input) and you can think of it as being an attempt by nature to "even up" the difference. Water passes into the stronger solution, i.e. the one with the higher concentration of solutes. If equilibrium is reached, the process will stop.One example of the importance of osmosis: mature plant cells contain a central vacuole, holding an aqueous solution of various chemical compounds. These solutes create an osmotic pressurethat attracts water, swelling the vacuole and giving the cells turgor. The turgor of cells in well-watered plants holds up soft parts like leaves. If a plant lacks water, the vacuoles shrink and the leaves wilt.
What process is the diffusion of water through a selectively permeable membrane?
This is the process of osmosis. The membrane allows a solvent (usually water) to move from an area with lower solute concentration to one with greater concentration.
Definition of impermeable membrane?
im·per·me·a·ble   [im-pur-mee-uh-buhl] Show IPA adjective1.not permeable; impassable.2.Chemistry, Geology . (of porous substances, rocks, etc.) notpermitting the passage of a fluid through the pores,interstices, etc.
How is the function of epithelium reflected in its structure?
Since epithelium needs to serve as both a barrier and selectively permeable membrane, the cells need to be tightly junctioned to one another (thus prohibiting paracellular transport) and need to express channels, transporters or exchangers to allow for movement of selected ions/molecules across the epithelial barrier
State one possible reason a certain substance can not pass across a cell membrane?
The cell membrane is selectively permeable. Some substances like molecules are too big to pass through the membrane. The membrane allows passive transport of moleculesÊ by filtration, diffusion, or osmosis.
What is diffusion and osmosis?
Diffusion is the tendency of particles in a gas or liquid to become evenly distributed by moving from areas of greater concentration to areas of lesser concentration. Diffusion is driven by the kinetic energy of particles that is a consequence of temperature. It is an inherently random process and particles continue to spread out until they are evenly distributed within the enclosed area.Biologically, diffusion is the cause of random movement or net movement of particles from an area of high concentration towards an area of low concentration. Osmosis refers to the flow of particles across a membrane. When active transport is absent, diffusion provides the driving force for osmosis across a fully permeable or partially permeable membrane.Fully permeable: all particles can move through.Partially permeable: only certain particles an move through.Active transport: biochemical processes expend energy to move particles.Note: Reverse osmosis is basically filtering. Pressure is greater on one side of a partially permeable membrane pushing particles through it.
Does water flow in or out in osmosis?
Osmosis is the movement of water from a high concentration to a low concentration through a selectively permeable membrane until it is evenly spread. Depending on the concentration of the two solutions, water could flow in either direction, going from the one with MORE water to the one with LESS water.
Why is cell membrane differentially permeable?
Selective (or differential) permeability allows the cell to regulate its internal environment and maintain internal homeostasis. This is also the basis by which a neuron (nerve cell) can 'fire' and send a message along its axon - it selectively allows one electrolyte then a different electrolyte to flow across its cell membrane and change the electrochemical gradient.
