Chapter 2 Flashcards
Define acid
compound that releases hydrogen ions (H+) in solution
Define activation energy
amount of energy greater than the energy contained in the reactants, which must be overcome for a reaction to proceed
Define adenosine triphosphate (ATP)
energy carrying molecule found in cells of all living things. Captures chemical energy obtained from breakdown of food molecules and releases it to fuel other cellular process
Define amino acids
building blocks of proteins; characterized by an amino and carboxyl functional groups and a variable side-chain
Define anion
atom with a negative charge
Define atom
smallest unit of an element that retains the unique properties off that element
Define atomic number
number of protons in the nucleus of an atom
Define base
compound that releases hydroxyl ions (OH-) or compound that accepts hydrogen ions (H+) in solution
Define bond
electrical force linking atoms
Define buffer
solution containing a weak acid or a weak base that prevents wide fluctuations in the pH of body fluids
Define carbbohydrates
class of organic compounds built from sugars, molecules containing carbon, hydrogen, and oxygen in a 1-2-1 ratio
Define catalyst
substance that increases the rate of a chemical reaction without itself being changed in the process
Define cation
atom with a positive charge
Define chemical enegry
the form of potential energy stored within atoms and molecules. observed when a chemical reaction occurs or matter changes forms
Define colloid
liquid mixture in which the solute particles consist of clumps of molecules large enough to scatter light (homogenous)
Define compound
substance composed of two or more different elements joined by chemical bonds
Define concentration
number of particles within a given space
Define covalent bond
chemical bond in which two atoms share electrons, thereby completing their valance shells
Define decomposition reaction
type of catabolic reaction in which one or more bonds within a large molecule are broken, resulting in the release of smaller molecules or atoms
Define denaturation
change in the structure of a molecule through physical or chemical means
Define deoxyribonucleic acid (DNA)
deoxyribose-containing nucleotide that stores genetic information
Define disaccharide
pair of carbohydrate monomer bonded by dehydration synthesis via a glycosidic bond
Define disulfide bond
covalent bond formed within a polypeptide between sulfide groups of sulfur-containing amino acids, for example, cysteine
Define electron
subatomic particle having a negative charge and nearly no mass; found orbiting the atom’s nucleus
Define electron shell
area of space a given distance from an atom’s nucleus in which electrons are grouped
Define element
substance that cannot be created or broken down by ordinary chemical means
Define enzyme
protein or RNA that catalyzes chemical reactions
Define exchange reaction
type of chemical reaction in which bonds are both formed and broken , resulting in the transfer of components
Define functional group
group of atoms linked by strong covalent bonds that tends to behave as a distinct unit in chemical reactions with other atoms
Define hydrogen bond
A weak bond between two molecules resulting from an electrostatic attraction between a proton in one molecule and electronegative atom in the other
Define inorganic compound
substance that does not contain both carbon and hydrogen
Define ion
atom with an overall positive or negative charge
Define ionic bond
attraction between an anion and a cation
Define isotopes
One of two or more species of atoms of a chemical element that contain equal numbers of protons but different number of neutrons in nuclei
Define kinetic energy
energy that matter posses because of its motion
Define lipid
Class of organic compounds that are fatty acids or their solvents
Define macromolecule
large molecule formed by covalent bonding
Define mass number
sum of the number of protons and neutrons in the nucleus of an atom
Define matter
physical substance; that which occupies space and has mass
Define molecule
two or more atoms covalently bonded together
Define monosaccharide
monomer of carbohydrates; also known as a simple sugar
Define neutron
heavy subatomic particle having no electrical chargge and found in the atom’s nucleus
Define nucleotide
class of organic compounds composed of one or more phosphate groups, a pentose sugar, and a base
Define organic compound
substance that contains both carbon and hydrogen
Define peptide bond
covalent bond formed by dehydration synthesis between two amino acids
Define periodic table of elements
arrangement of the elements in a table according to their atomic number; elements having similar properties because of their electron arrangements compose columns in the table, while elements having the same number of valence shells compose rows in the table
Define pH
negative logarithm of the hydrogen ion (H+) concentration of a solution
Define phospholipids
a lipid compound in which a phosphate group is combined with a diglyceride
Define phosphorylation
addition of one of more phosphate groups to an organic compound
Define polar molecule
chemical species in which the distribution of electrons between covalently bonded atoms is not even
Define polysaccharide
compound consisting of more than two carbohydrate monomers bonded by dehydration synthesis via glycosidic bonds
Define potential energy
energy stored in an object due to its position relative to some zero position
Define product
one or more substances produced by a chemical reaction
Define prostaglandin
Group of lipids made at sites of tissue damage or infection that are involved in dealing with injury and illness. They control processes such as inflammation, blood flow, the formation of blood clots and induction of labor
Define protein
class of organic compounds that as composed of many amino acids linked together by peptide bonds
Define proton
heavy subatomic particle having a positive charge and found in the atom’s nucleus
Define purine
nitrogen-containing base with a double ring structure; adenine and guanine
Define pyrimidine
nitrogen-containing base with a single ring structure; cytosine, thiamine, and uracil
Define radioactive isotope
unstable, heavy isotope that gives off subatomic particles, or electromagnetic energy, as it decays; also called radioisotopes
Define reactant
one or more substances that enter into the reaction
Define ribonucleic acid (RNA)
ribose-containing nucleotide that helps manifest the genetic code as protein
Define solution
homogeneous liquid mixture in which a solute is dissolved into molecules within a solvent
Define steroid
Large class of organic compounds with a characteristic molecular structure containing four rings of carbon atoms (hormones, alkaloids, vitamins)
Define substrate
reactant in an enzymatic reaction
Define suspension
liquid mixture in which particles distributed i the liquid settle out over time
Define synthesis reaction
type of anabolic reaction in which two or more reactants combine to form a single product
Define triglyceride
lipid compound composed of a glycerol molecule bonded with three fatty acid chains
Define valence shell
outermost electron shell of an atom
