Semipermeable membrane.
Semi-permeable. Permeable means things can pass through, so semi-permeable means only some things can pass through.
A semi-permeable membrane is a membrane that allows certain substances to pass through while preventing others from crossing. It selectively permits the passage of molecules based on size and charge. This property is crucial in biological processes such as osmosis and filtration.
The cell membrane will only allow certain molecules access. For example, glucose molecules are too large to pass through the cell membrane without undergoing endocytosis, but water molecules can easily pass through the cell membrane.
Also small molecules.Basically because the cell membrane is amphipathic; a polar head and non-polar tails make up the double layered membrane with non-polar tails sticking inward and polar heads outward. This means that the non-polar middle, the lipid part, does not allow hydrophyllic substances to pass easily through the membrane while non-polar substances can pass through easily. Having to do with charge and solubility.
When substances are too large to pass through the cell membrane directly (they'd leave a gaping hole), they are enclosed in a lipid sac that is similar in composition to the cell membrane. Instead of punching through the membrane, the sac merges with it allowing the large substance to exit the cell without damaging the membrane.
Semi-permeable. Permeable means things can pass through, so semi-permeable means only some things can pass through.
A semi-permeable membrane is a membrane that allows certain substances to pass through while preventing others from crossing. It selectively permits the passage of molecules based on size and charge. This property is crucial in biological processes such as osmosis and filtration.
Selectively permeable means that only certain substances are able pass through the cell membrane.A selectively permeable membrane is a membrane that only can be permeated by selective things, in other words a surface that lets some molecules in but not others. Like a cell membrane will let water diffuse into it :)
The cell membrane is considered to be semipermeable. This means that it will let some substances through (either in or out), but others it won't. The cell membrane is considered to be 3 layers (lipid, protein, lipid) Certain proteins will help substances into the cell, but some they won't let in. Generally, smaller molecules (oxygen, water, CO2, etc.) will pass through easier than larger molecules (glucose, other sugars). Basically, the cell membrane determines what substances are allowed to pass it/out of the cell.
The cell membrane will only allow certain molecules access. For example, glucose molecules are too large to pass through the cell membrane without undergoing endocytosis, but water molecules can easily pass through the cell membrane.
Also small molecules.Basically because the cell membrane is amphipathic; a polar head and non-polar tails make up the double layered membrane with non-polar tails sticking inward and polar heads outward. This means that the non-polar middle, the lipid part, does not allow hydrophyllic substances to pass easily through the membrane while non-polar substances can pass through easily. Having to do with charge and solubility.
A cell membrane is found on both plant and animal cells it selectively chooses what substances may enter or leave the cell. Hence the term selectively permeable. For a more advanced explanation I recommend you research protein icebergs and the different types of transport a membrane can take part in. Example active transport
When substances are too large to pass through the cell membrane directly (they'd leave a gaping hole), they are enclosed in a lipid sac that is similar in composition to the cell membrane. Instead of punching through the membrane, the sac merges with it allowing the large substance to exit the cell without damaging the membrane.
A selectively permeable membrane means that it lets some molecules through but others can't get in.
It is very selective about what it allows to pass through.
Cell membranes are selective barriers because they only let certain substances pass through and therefore ensures the cells survival.
it is permeable to some molecules and not permeable to others.