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CHCS 7th Ch 4A
CHCS Life Science Chapter 4 (p50-54)
Question | Answer |
---|---|
cell membrane | a thin covering that forms the outer boundary of a cell |
selectively permeable | an important characteristic of membranes; certain molecules are allowed to pass through the membrane, while others are not |
passive transport | the movement of substances through a membrane without the use of the cell's own energy; diffusion and osmosis are types of passive transport |
2 types of passive transport | diffusion and osmosis |
diffusion | the movement of molecules from an area of high concentration to an area of low concentration |
osmosis | the movement of water through a membrane from an area of high concentration to an area of low concentration |
Anton von Leeuwnhoek | invented the compound microcope; looked at pondwater; called the moving organisms he saw "wee-beasties" or "animalcules" |
active transport | requires the cell to use its own energy to move substances through a membrane |