Biology Vocab - Chapter 6

acid

substance that releases hydrogen ions (H+) when dissolved in water, an acidic solution has a pH less than 7

activation energy

minimum amount of energy needed for reactants to form products in a chemical reaction

active site

specific place where a substrate binds on an enzyme

amino acid

carbon compound joined by peptide bonds; building block of proteins

atom

building block of matter ; contains subatomic particles - neutrons, protons, and electron

base

substance that releases hydroxide ions (OH-) when dissolved in water; a basic solution has a pH greater than 7

buffer

mixture that can react w/ an acid or a base to maintain the pH within a specific range

carbohydrate

organic compound containing carbon, hydrogen, and oxygen in a ration of one oxygen and 2 hydrogen atoms for each carbon atom

catalyst

substance that speeds up a chemical reaction by reducing the activation energy

chemical reaction

energy-requiring process by which atom or group of atoms in substances are changed into different substances

compound

pure substance with unique properties; formed when two or more different elements combine

covalent bond

type of chemical bond formed when atoms share electrons

electron

negatively charged particle that occupies space around an atoms nucleus

element

pure substance composed of only one type of atom; cannot be broken down into another substance by physical or chemical means

enzyme

protein that speeds up a biological reaction by lowering the activation energy needed to start the reaction

hydrogen bond

weak electrostatic bond formed by the attraction of opposite charges between a hydrogen atom and an oxygen, fluorine, or nitrogen atom

ion

atom that is negatively or positively charged because it has lost or gained one or more electrons.

ionic bond

electrical attraction between two oppositely charged atoms or groups of atoms

isotope

two or more atoms of the same element having different numbers of neutrons

lipid

hydrophobic biological molecule composed mostly of carbon and hydrogen; hats, oils and waxes are ______.

macromolecule

large molecule formed by joining a smaller organic molecules together

mixture

combination of 2 or more different substances in which each substance keeps its individual characteristics; can have a uniform composition (homogeneous) or have distinct areas of substances (heterogeneous)

molecule

compound whose atoms are held together by covalent bonds

neutron

particle without a change in an atoms nucleus

nucleic acid

complex macromolecule that stores and communicate genetic information

nucleotide

a subunit of nucleic acid formed from a simple sugar, a phosphate group, and a nitrogenous base

nucleus

center of an atom; contains neutrons and protons. in eukaryotic cells, the central membrane-bound organelle that manages cellular functions and contains DNA

pH

measure of the concentration of hydrogen ions (H+) in a solution

polar molecule

molecule with oppositely charged regions

polymer

large molecule formed from smaller repeating units of identical or nearly identical, compounds linked by covalent bonds

product

substance formed by a chemical reaction; located on the right side of the arrow in a chemical equation

protein

organic compound made of amino acids joined by peptide bond; primary building block of organisms

proton

positively charged particle in an atoms nucleus

reactant

substance that exists before a chemical reaction starts; located on the left side of the arrow in a chemical equation

solute

substance dissolved in a solvent

solution

another name for a homogeneous mixture

solvent

substance in which another substance is dissolved

substrate

reactant to which an enzyme binds

van cler waals force

attractive forces between molecules