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chapter 2-bio vocab
Term | Definition |
---|---|
atom | the smallest unit of an element that maintains the chemical properties of that element |
element | a substance that cannot be separated, or broken down into simpler substances by chemical means; all atoms of an element have the same atomic number |
compound | a substance made up of atoms of two or more different elements joined by chemical bonds |
ion | an atom, radical, or molecule that has gained or lost one or two electrons and has a negative positive charge |
ionic bond | the attractive force between oppositely charged ions, which form when electrons are transferred from one atom to another. |
covalent bond | a bond formed when atoms share one or more pairs of electrons |
molecule | a group of atoms that are held together by chemical forces; a molecule is the smallest form of matter that cam exist by itself and retain all of a substance's chemical properties |
hydrogen bond | the inter molecular force occurring when a hydrogen atom that is bonded to a highly electronegative atom of one molecle is attracted to two unshared electrons of another molecule |
cohesion | the force that holds molecules of a single material together |
adhesion | the attractive force between two bodies of different substances that are in contact with each other |
solution | a homogeneous mixture throughout which two or more substances are uniformly dispersed |
solvent | in a solution, the substance in which the solute dissolves |
solute | in a solution, the substance that dissolves in the solvent |
acid | any compound that increases the number of hydronium ions when dissolved in water; acids turn blue litmus paper red and react with bases and some metals to form salts |
base | any compound that increases the number of hydroxide ions when dissolved in water; bases turn red litmus paper blue and react with acids to form salts |
pH | measurement of acidity; related to free hydrogen ion concentration in solution |
monomer | molecular subunit of a polymer |
polymer | a large molecule that is formed by more than 5 monomers, or samll units |
carbohydrate | a class of molecules that include sugar, starches, and fibers; contains carbon, hydrogen, and oxygen |
lipid | a fat molecule or a molecule that has similar properties; examples include oils, waxes, and steroids |
fatty acid | hydrocarbon chain often bonded to glycerol in a lipid |
protein | an organic compound that is made of one or more chains of amino acids and that is a principal component in all cells |
amino acid | a compound of a class of simple organic compounds that contain a carboxylic group and an amino group and that combine to form proteins |
nucleic acid | an organic compound named either RNA or DNA, whose molecules are made up of one or two chains of nucleotide and contain genetic information |
chemical reaction | process by which substances change into different substances through the breaking and forming of chemical bonds |
reactant | a substance or molecule that participates in a chemical reaction |
product | a substance that forms in a chemical reaction |
bond energy | amount of energy needed to break a bond between two particular atoms; of the amount of energy released when a bond forms between two particular atoms |
equilibrium | in biology, the state that exists when the concentration of a substance is the same throughout the space |
activation energy | the minimum amount of energy needed to start a chemical reaction |
exothermic | a chemical reaction that yields a net release of energy in the form of heat |
endothermic | chemical reaction that requires a net input of energy |
catalyse | substance that decreases activation energy and increases reaction rate in a chemical reaction |
enzyme | a molecule, either protein or RNA, that acts as a catalyst in biochemical reactions |
substrate | a part, substance, or element that lies beneath and supports another part , substance, or element; the reactant in reactions that catalyst by enzymes |