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cell theory

All living things are composed of cells. Cells are the basic units of structure & function in living things. New cells are produced from existing cells.


specialized structure that performs important cellular functions w/in a eukaryotic cell


structure that contains the cell's genetic material (DNA) & controls its activitiesTranslation of mRNA happens here


unicellular organism w/out a nucleus; their genetic material is not in a nucleus


unicellular or multicellular organism whose cells contain nuclei; genetic material is contained in a nucleus

Unicellular / Multicellular

Unicellular- single-celled organismMulticellular-organisms that are made up of many cells

Lipid Bi-Layer

2 layers of lipid (fatty) moleculesfound in cell membrane

Semi-Permeable Membrane

only allows certain or specific items to pass throughcell membrane is semi-permeable

Active Transport

going against the concentration gradientenergy-requiring process that moves material in the opposite direction or across a cell membrane against a concentration differencegoing from a low concentration to a high concentrationrequired energy- ATP used in cellular respiration & sunlight in Photosynthesis

Facilitated Transport

helper molecule required to get through semi-permeable membrane by protein channelsno energy required, it moves w/ the concentration gradientgoing from high concentration to low concentrationEX- salt, sugars, ions, ATP SYNTHASE


diffusion of water across the semi-permeable cell membranewater molecules will move from areas or solutions w/ high concentration to areas w/ lower concentration


process by which molecules tend to move from an area where they are more concentrated to an area where they are less concentrated; once they are equal they are in equilibrium; molecules cont. to move even after equilibrium


collection of living matter enclosed by a barrier that separates the cell from its surroundsbasic unit of all forms of lifesmallest levelspecialized function


made of cellsgroup of cells working together to do a job


group of tissues working together to perform closely related functions

Organ System

group of organs working together to perform a specific function

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