1a. Osmosis: Osmosis is the diffusion of water across a selectively permeable membrane. Cell membranes have pores that are where molecules pass through the membrane. These pores are too small for some molecules like sugar to pass through, but are large enough for water molecules. These water molecules move across the membrane from areas of low concentrations of solute to high concentrations of solute. The different concentrations affect the water level. However, when a solution is dilute, the solutes do not affect the water concentration (level). This process is passive meaning it does not require any energy.
1b. Osmosis: In animal cells, osmosis is needed to keep the cell in normal condition where it is isotonic. To maintain this, water …show more content…
Facilitated Diffusion: Facilitated diffusion is a type of passive transport aided by proteins embedded within the membrane. Transport proteins speed the passive movement of molecules across the plasma membrane. Channel proteins, in facilitated diffusion, provide corridors that allow specific molecules or ions to cross the membrane. Carrier proteins undergo a subtle change in shape that translocates the solute binding site across the membrane allowing the specific molecules to cross the membrane. These substances move from high to low concentrations or down their concentration …show more content…
Endocytosis and Exocytosis: Small molecules and water can pass through the cell through the lipid bilayer or through transport proteins. Large molecules like polysaccharides and proteins, cross the membrane with the help of vesicles. Endocytosis is when the cell takes in macromolecules by forming vesicles from the plasma membrane. There are three types of endocytosis: phagocytosis (cellular eating), pinocytosis (cellular drinking), and receptor-mediated. Endocytosis has to do with large substances coming into the cell. Exocytosis is when transport vesicles migrate to the membrane and then fuse with it and release their contents. Many secretory cells, like those found in the pancreas use exocytosis to export their products. Exocytosis has to do with large molecules leaving the cell. The vesicles in this process, can rejuvenate and remodel the plasma membrane. This process is powered by
1b. Osmosis: In animal cells, osmosis is needed to keep the cell in normal condition where it is isotonic. To maintain this, water …show more content…
Facilitated Diffusion: Facilitated diffusion is a type of passive transport aided by proteins embedded within the membrane. Transport proteins speed the passive movement of molecules across the plasma membrane. Channel proteins, in facilitated diffusion, provide corridors that allow specific molecules or ions to cross the membrane. Carrier proteins undergo a subtle change in shape that translocates the solute binding site across the membrane allowing the specific molecules to cross the membrane. These substances move from high to low concentrations or down their concentration …show more content…
Endocytosis and Exocytosis: Small molecules and water can pass through the cell through the lipid bilayer or through transport proteins. Large molecules like polysaccharides and proteins, cross the membrane with the help of vesicles. Endocytosis is when the cell takes in macromolecules by forming vesicles from the plasma membrane. There are three types of endocytosis: phagocytosis (cellular eating), pinocytosis (cellular drinking), and receptor-mediated. Endocytosis has to do with large substances coming into the cell. Exocytosis is when transport vesicles migrate to the membrane and then fuse with it and release their contents. Many secretory cells, like those found in the pancreas use exocytosis to export their products. Exocytosis has to do with large molecules leaving the cell. The vesicles in this process, can rejuvenate and remodel the plasma membrane. This process is powered by