Transcript Ch. 6 Vocabulary

Advanced Biology
 Atoms – the building blocks of matter
 Nucleus – the center of the atom; the location of





neutrons and protons
Protons – positively charged particles (p+)
Neutrons – particles that have no charge (n0)
Electrons – negatively charged particles that are
located outside the nucleus (e-)
Element – a pure substance that cannot be broken
down into other substances by physical or chemical
means
Isotopes – atoms of the same element that have
different numbers of neutrons
 Compound – a pure substance formed when two or more





different elements combine
Covalent Bond – the chemical bond that forms when
electrons are shared
Molecule – a compound in which the atoms are held
together by covalent bonds
Ion – an atom that has lost or gained one or more electrons
Ionic Bond – an electrical attraction between two
oppositely charged atoms or groups of atoms called ions
Van der Waals Forces – when molecules come close
together, the attractive forces between these positive and
negative regions pull on the molecules and hold them
together
 Chemical Reaction – the process by which atoms or





groups of atoms in substances are reorganized into
different substances
Reactants – the starting substances in a reaction
Products – the substances formed during a reaction
Activation Energy – the minimum amount of energy
needed for reactants to form products in a chemical
reaction
Catalyst – a substance that lowers the activation
energy needed to start a chemical reaction
Enzymes – a protein and biological catalysts that
speed up the rate of chemical reactions in biological
processes
 Substrates – the reactants that bind to the enzymes
 Active Site – the specific location where a substrate




binds on an enzyme
Polar Molecules – molecules that have an unequal
distribution of charges
Hydrogen Bond – a weak interaction involving a
hydrogen atom and a fluorine, oxygen, or nitrogen
atom
Mixture – a combination of two or more substances in
which each substance retains its individual
characteristics and properties
Solution – a mixture that has a uniform composition
throughout; also called homogeneous
 Solvent – a substance in which another substance is






dissolved in
Solute – the substance that is dissolved in the solvent
Acids – substances that release hydrogen ions (H+)
when dissolved in water
Bases – substances that release hydroxide ions (OH-)
when dissolved in water
pH – the measure of concentration of H+ in a solution
Buffers – mixtures that can react with acids or bases to
keep the pH within a particular range
Macromolecules – large molecules that are formed by
joining smaller organic molecules together
 Polymers – molecules made from repeating units of




identical or nearly identical compounds called
monomers that are linked together by a series of
covalent bonds
Carbohydrates – Compounds composed of carbon,
hydrogen, and oxygen in a ratio of one oxygen and two
hydrogen atoms for each carbon atom
Lipids – molecules made mostly of carbon and
hydrogen that make up the fats, oils, and waxes
Protein – a compound made of small carbon
compounds called amino acids
Amino Acids – small compounds that are made of
carbon, nitrogen, oxygen, hydrogen, and sometimes
sulfur
 Nucleic Acids – complex macromolecules that store
and transmit genetic information
 Nucleotides – smaller repeating subunits composed of
carbon, nitrogen, oxygen, phosphorus, and hydrogen
atoms that make up nucleic acids