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Chapter 4

Basic Unit of Life

ATP Adenosine triphosphate; a molecule in all living cells that acts as fuel
hormone a chemical signal used to control body function
microscope an instrument used to magnify things
cell theory a theory that all living things are made of cells, that cells are the basic units of structure, and that cells only come from already present cells
homeostasis the ability of organisms to maintain their internal conditions
transport to move molecules from one side of a membrane to the other
concentration a measurement of the amount of dissolved substance in a fixed amount of solvent
diffusion the movement of molecules from an area of high concentration to an area of low concentration
selectively permeable membrane a membrane that allows some molecules to pass but blocks other molecules from coming through
concentration gradient a difference in the concentration of a substance across a distance
osmosis the movement of water through a cell membrane
hypotonic a solution whose solute concentration is lower than the solute concentration another solution
solute a dissolved substance
hypertonic a solution whose solute concentration is higher than the solute concentration of another solution
isotonic a solution whose solute concentration is equal to the solute concentration of another solution
equilibrium a state where concentration are equal in all parts of an area
prokaryote a cell with only one outside membrane and no nucleus or other internal structures
binary fission reproduction in which a bacterial cell divides into two sells that look the same as the original cell
eukaryote a cell with several internal structures, including the nucleus, that are surrounded by membranes
organelle a tiny membrane-bound structure inside a cell
tissue a group of cells that are similar and work together
epithelial cell a skin cell
nervous tissue nerves made from collections of nerve cells
organ a group of different tissues that work together to perform specific connected tasks
organ system a group of organs that work together to perform specific connected tasks
circulatory system a collection of organs, including the heart, which moves blood and gases throughout the body
Created by: mrspuffisphat21