Chapter 2 Flashcards
A molecule that releases a proton when dissolved in water; generates hygronium ions, thereby lowering pH.
Acid
Small organic molecule containing both an amino group and a carboxyl group; serves as the building block of proteins.
Amino acid
The smallest particle of an element that still retains distinctive chemical properties; consists of a positively charged nucleus surrounded by a cloud of negatively charged electrons.
Atom
The mass of an atom expressed in daltons, the atomic mass unit that closely approximates the mass of a hydrogen atom.
Atomic mass
Molecule that serves as the principal carrier of energy in cells; composed of adenine, ribose, and three phosphate groups.
ATP
Molecule that accepts a proton when dissolved in water; used to refer to the nitrogen-containing purines or pyrimidines in DNA and RNA.
Base
Mixture of weak acids and bases that maintains the pH solution by releasing and taking up protons.
Buffer
An exchange of electrons that holds two atoms together.
Chemical bond
Combination of atoms, or an amino group, with distinct chemical and physical properties that influences the behavior of the molecule in which it resides.
Chemical group
Chemical reaction in which a covalent bond is formed between two molecules as water is expelled; used to build polymers.
Condensation reaction
Precise, three-dimensional shape of a protein or other macromolecule based on the spatial location of its atoms in relation to one another.
Conformation
Stable chemical link between two atoms produced by sharing one or more pairs of electrons.
Covalent bond
Force that draws together oppositely charged atoms.
Electrostatic attraction
Molecule that consists of a carboxylic acid attached to a long hydrocarbon chain.
Fatty acid
A weak noncovalent interaction between a positively charged hydrogen atom in one molecule and a negatively charged atom.
Hydrogen bond
Chemical reaction that involves cleavage of a covalent bond with the accompanying consumption of water.
Hydrolysis
Molecule or part of a molecule that readily forms hydrogen bonds with water, allowing it to dissolve.
Hydrophillic
Nonpolar, uncharged molecule or part of a molecule that forms few or no hydrogen bonds with water molecules and therefore do not dissolve.
Hydrophobic
Not composed of carbon and hydrogen
Inorganic
An atom carrying an electrical charge, either positive or negative.
Ion
Interaction formed when one atom donates electrons to another, making both atoms become electrically charged.
Ionic bond
Organic molecule that is insoluble in water but dissolves in nonpolar organic solvents.
Lipid
Thin pair of closely juxtaposed sheet, composed mainly of phospholipid molecules, that forms the structural basis for all cell membranes.
Lipid bilayer
Polymer built from covalently linked subunits; includes proteins, nucleic acids, and polysaccharides with a molecular mass greater than a few thousand daltons.
Macromolecule
Sum of the atomic weights of the atoms in a molecule; as a ratio of molecular masses, it is a number without units.
Molecular weight
Group of atoms joined together by covalent bonds.
Molecule
Small molecule that can be linked to others of a similar type to form a larger molecule.
Monomer
Does not involve the sharing of electrons; singly they are weak, but can sum together to produce strong interactions between molecules.
Noncovalent bond
Basic building blocks of the nucleic acids, DNA and RNA.
Nucleotide
Chemical compound that contains carbon and hydrogen.
Organic molecule
Long molecule made by covalently linking multiple or similar subunits.
Polymer
A monomer that forms part of a larger molecule.
Subunit
Weak noncovalent interaction, due to fluctuation electrical charges, that comes into play between two atoms within a short distance of each other.
van der Waals attraction
Molecule containing the functional group -CONH2.
Amide
Molecule containing an amino group-NH2.
Amine
Negatively charged ion.
Anion
Positively charged ion.
Cation
Chemical linkage formed when two atoms share four electrons.
Double bond
Membrane lipid molecule that has a short carbohydrate chain attached to its hydrophillic head.
Glycolipid
A double-ringed, nitrogen-containing compound found in DNA and RNA.
Purine
A nitrogen-containing, six membered ring compound found in DNA and RNA.
Pyrimidine
Any substance that is dissolved in a lipid.
Solute
