3.2 membranes 7th grade
What is something that is semi-permeable?
Cell membrane: Allowing passage of certain, especially small, molecules or ions but acting as a barrier to others.
endocytosis
Cellular uptake of biological molecules and particulate matter via formation of new vesicles from the plasma membrane.
How are diffusion and osmosis different?
Diffusion allows small molecules to move across the cell membrane and osmosis is the diffusion of water molecules through a selectively permeable membrane
active transport
Energy-requiring process that moves material across a cell membrane against a concentration difference
What does selectively permeable (semi-permeable) mean?
It is a property of cell membranes that allows some substances to pass through, while others cannot.
What is equilibrium?
Molecules will continue to move from high to low until they are equal on both sides on the membrane
What is diffusion?
Movement of molecules from an area of higher concentration to an area of lower concentration.
Diffusion movement
Particles move from high concentration to low concentration.
Does osmosis require energy?
Passive transport like osmosis do not require energy.
Diffusion and osmosis are what kind of transport?
Passive, The movement across a concentration gradient does not require energy.
exocytosis
Process of exporting proteins from a cell by a vesicle fusing with the cell membrane
passive transport
Requires NO energy, Movement of molecules from high to low concentration, Moves with the concentration gradient
What is osmosis
The diffusion of water through a selectively permeable membrane.
Does diffusion require energy?
The movement from particles of higher to lower concentration does not require energy.
Example of diffusion?
The smell of popcorn popping diffuses throughout a house and is noticed in an adjacent room. Oxygen from air diffuses into lung alveoli.
osmosis
Water moves from low concentration of minerals to high concentration
How are diffusion and osmosis similar?
they move molecules from a high concentration area to a low concentration area