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Plasma Membrane

The membrane at the boundary of every cell that acts as a selective barrier, thereby regulating the cell's chemical composition.


a jellylike fluid inside the cell in which the organelles are suspended


network of protein filaments within some cells that helps the cell maintain its shape and is involved in many forms of cell movement


Material present in the cytoplasm of all eukaryotic cells, important during cell division; the microtubule-organizing center.


the region of the chromosome that holds the two sister chromatids together during mitosis


short, hair-like structures made of microtubules that enable movement of cells or movement of materials outside a cell


non membrane bounded organelles responsible for protein synthesis

Rough Endoplasmic Reticulum

a region that is recognized by the grainy appearance of the ribosomes on their outer surface, where the cell's proteins are made

Smooth Endoplasmic Reticulum

An endomembrane system where lipids are synthesized, calcium levels are regulated, and toxic substances are broken down.

Golgi complex

a cell organelle that helps make and package materials to be transported out of the cell


cell organelle that converts the chemical energy stored in food into compounds that are more convenient for the cell to use


Powerhouse of the cell, organelle that is the site of ATP (energy) production


a part of the cell containing DNA and RNA and responsible for growth and reproduction

passive transport

movement of substances through a cell membrane without the use of cellular energy; includes diffusion, osmosis, and facilitated diffusion

Active Trasnport

transport of a substance (as a protein or drug) across a cell membrane against the concentration gradient


process by which molecules tend to move from an area where they are more concentrated to an area where they are less concentrated


a transport protein in the plasma membrane of a plant or animal cell that specifically facilitates the diffusion of water across the membrane

Channel-mediated Facilitated Diffusion

a process in which a solute moves down its concentration gradient through a membrane channel (mostly ion channels) which may be gated or not gated; this process is slower tha simple diffusion


diffusion of molecules through a semipermeable membrane from a place of higher concentration to a place of lower concentration until the concentration on both sides is equal

Carrier-mediated Facilitated


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