Notes

adenosine triphosphate the high energy chemical compound with three phosphate groups that provides energy for all other cell activities; (ATP)
cellular respiration chemical reactions in plants and animals that break down food molecules into energy (ATP)
diffusion movement of particles or molecules from higher concentration to lower concentration
endocytosis when cells engulf or ingest substances
exocytosis when cells expel or get rid of substances from within
homeostasis the relatively constant state in the internal environment of an organism
hypertonic a solution that has a higher salt concentration than the salt concentration inside the cells
hypotonic a solution that has a lower salt concentration than the salt concentration inside the cells
isotonic a solution with the same salt concentration as the salt concentration inside the cells
osmosis the diffusion of water across a semipermeable membrane
phagocytosis when cells eat other cells or large substances
phospholipid a molecule with polar and nonpolar ends that, along with protein, makes up the plasma membrane
pinocytosis when cells eat small or dissolved substances
polar molecule a molecule that has partial positive and negative charges at each end
protein a large, complex organic molecule consisting of a large number of amino acids linked together by peptide bonds