Biology 120: Exam 1 Questions And Answers Rated A+

active transport - transport of a substance (as a protein or drug) across a cell membrane against the concentration gradient, using energy adhesion - an attraction between molecules of different substances; water attracts polar molecules amino acid - organic compounds containing an amino group (-NH2) and a carboxylic acid group (- COOH), compose proteins Biology - the study of living organisms and their associated phenomena capillary action - the attraction of the surface of a liquid to the surface of a solid, which causes the liquid to rise or fall carrier proteins - carry molecules that cannot pass through the cell membrane because they are too large or insoluble catalyst - a substance that initiates or accelerates a chemical reaction without itself being affected cell surface markers - identify the cell type, i.e. glycoproteins and glycolipids cell theory - idea that all living things are composed of cells, cells are the basic units of structure and function in living things, and new cells are produced from existing cells cell-surface markers - a membrane protein that identifies the cell type; include glycoproteins and glycolipids channel proteins - proteins that provide passageways through the membrane for certain hydrophilic (water-soluble) substances such as polar and charged moleculesCHNOPS - The most common elements in living organisms: Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, Sulfur cohesion - Attraction between molecules of the same substance; water attracts itself, i.e. plant transpiration, evaporation control - a standard against which other conditions can be compared in a scientific experiment covalent bond - a chemical bond that involves sharing a pair of electrons between atoms in a molecule, share electrons and form true molecules, relatively strong