Chapter 1 Flashcards
a form of an element that differs in its numbers of neutrons
isotope
a radioactive isotope of an element
radioisotope
a region of space that is occupied by electrons located around the nucleus of an atom
orbital
an electron in the outermost energy level or shell of an atom
valence electron
a bond that results from the attraction between two oppositely charged atoms or molecules
ionic bond
an ion that has a positive charge
cation
an ion that has a negative charge
anion
the measure of an atom’s attraction to shared electrons
electronegativity
a bond between two atoms, made up of unequally shared electrons
polar covalent bond
partial positive or negative charge at the ends of a molecule
polarity
the force of attraction between two molecules
intermolecular force
very weak attractions between two molecules, or parts of molecules, when they are close together
van der Waals forces
the attractive force between two molecules, or parts of molecules, when they are close together
hydrogen bond
a chemical reaction in which subunits of a larger molecule are joined by the removal of water
dehydration reaction or condensation reaction
a chemical reaction in which water is used as a reactant to split a larger molecule into smaller subunits
hydrolysis
a reaction in which an acid and a base combine to create a salt and water
neutralization reaction
an electron transfer reaction
redox reaction
a reaction in which a molecule loses electrons
oxidation
a reaction in which a molecule gains electrons
reduction
the amount of thermal energy required to raise the temperature of a given quantity of a substance by 1 degree C
specific heat
water molecules form hydrogen bonds with each other
cohesion
water molecules form hydrogen bonds with other polar molecules
adhesion
hydrogen bonding causes water to absorb large amounts of thermal engery as its temperature increases, or lose large amounts of thermal energy as its temperature decreases
high specific heat capacity
hydrogen bonding causes liquid water to absorb large amounts of thermal energy and become a vapour
high specific heat of vaporization
high surface tension
cohesion
capillary action and solubility of polar compounds
adhesion
temperature moderation
high specific heat capacity
evaporation and cooling
high specific heat of vaporization
ice floats on water
solid water is less dense than liquid water
polar or charged molecules that are strongly attracted to water
hydrophilic molecules
non-polar molecules that are not strongly attracted to water
hydrophobic molecules
the process in which a molecule spontaneously dissociates into ions
autoionization
a chemical that compensates for pH changes in a solution by accepting or donating H+ ions
buffer
a group of atoms that affects the function of a molecule by participating in chemical reactions
functional group
a biomolecule that consists of carbon, oxygen, and hydrogen
carbohydrate
the simplest form of carbohydrate, consisting of single sugar unit; building block for more complex carbohydrates
monosaccharide
a molecule that has the same composition as another, but a different arrangement of atoms
isomer
a carbohydrate molecule that is made from two monosaccharide units
disaccharide
a bond between two monosaccharides
glycosidic bond
a molecule that is composed of hundreds to thousands of monosaccharides linked together; an essential part of nutrition and a valuable energy source
complex carbohydrate
a molecule that contains many linked monosaccharides
polysaccharide molecule
a process in which small subunits are linked to form a large molecule
polymerization
a small molecule that can bind chemically to other molecules
monomer
a large molecule that is formed when monomers link together chemically in a chain
polymer
a molecule that consists of a carboxyl group and a hydrocarbon chain
fatty acid
a fat; three fatty acid chains linked to a glycerol molecule
triglyceride
a lipid that is composed of saturated fatty acids with single bonds in their hydrocarbon chain
saturated fat
a lipid that is composed of unsaturated fatty acids with double bonds in their hydrocarbon chain
unsaturated fat
a lipid that consists of two fatty acids and a phosphate group bound to glycerol
phospholipid
a lipid that is composed of four carbon rings
steroid
a lipid that is formed when long fatty chains are joined to alcohols or carbon rings
wax
a large molecule that consists of many amino acid subunits that are joined together by peptide bonds folded into a specific three-dimensional shape
protein
a blueprint for proteins that are synthesized in cells; stores hereditary information
nucleic acid
a molecule that contains a carboxyl group and an amino group; serves as the monomer subunit of proteins
amino acid
a covalent bond that links to amino acids
peptide bond
a chain of amino acid subunits that are connected by peptide bonds
peptide
a peptide with more than 50 amino acids
polypeptide
the loss of both the structure and function of a protein
denaturation
the building block of nucleic acids; consists of 5-carbon sugar, a nitrogenous base, and one to three phosphate groups
nucleotide
a link that is formed between nucleotides by a phosphate bridge
phosphodiester bond
oriented in opposite directions
antiparallel
a biological catalyst, usually a protein, that speeds up a chemical reaction
enzyme
a substance that is recognized by and binds to an enzyme
substrate
a pocket or groove in an enzyme that binds its substrate
active site
a model of enzyme activity that describes how an enzyme changes shape to better accommodate a subsrate
induced-fit model
a non-protein group that binds to an enzyme and is essential for catalytic activity
cofactor
an organic molecule that acts as a cofactor of an enzyme
coenzyme
a situation in which a competitor substance binds to a normal substrate binding site to block enzyme activity
competitive inhibition
a situation in which molecules bind to an enzyme at a site that is not the active site, thus blocking enzyme activity
noncompetitive inhibition
a binding site on an enzyme that binds regulatory molecules
allosteric site
the regulation of one site of a protein by binding to another site on the same protein
allosteric regulation
the regulation of a pathway by one of the products of this pathway
feedback inhibition
