Molecules of Life Vocabulary

amino acid
An organic molecule possessing both carboxyl and amino groups. Amino acids serve as the monomers of proteins.
anabolic steroids
A synthetic variant of the male hormone testosterone that mimics some of its effects.
carbohydrate
A sugar (monosaccharide) or one of its dimers (disaccharides) or polymers (polysaccharides).
carbon skeleton
The chain of carbon atoms in organic molecules.
cellulose
A structural polysaccharide of cell walls, consisting of glucose monomers.
dehydration synthesis
A chemical process in which a polymer forms as monomers are linked by the removal of water molecules. One molecule of water is removed for each pair of monomers linked
denaturation
For proteins, a process in which a protein unravels and loses its native conformation, thereby becoming biologically inactive. For DNA, the separation of the two strands of the double helix. Denaturation occurs under extreme conditions of pH, salt concentration, and temperature.
deoxyribonucleic acid
(DNA) A double-stranded, helical nucleic acid molecule capable of replicating and determining the inherited structure of a cell's proteins.
disaccharide
A double sugar, consisting of two monosaccharides joined by dehydration synthesis.
double helix
The form of native DNA, referring to its two adjacent polynucleotide strands wound into a spiral shape.
fat
(triacylglycerol) A biological compound consisting of three fatty acids linked to one glycerol molecule.
functional group
A specific configuration of atoms commonly attached to the carbon skeletons of organic molecules and usually involved in chemical reactions.
glycogen
An extensively branched glucose storage polysaccharide found in the liver and muscle of animals; the animal equivalent of starch.
hydrocarbon
An organic molecule consisting only of carbon and hydrogen.
hydrolysis
A chemical process that lyses, or splits, molecules by the addition of water; an essential process in digestion.
hydrophilic
Having an affinity for water.
hydrophobic
Having an aversion to water; tending to coalesce and form droplets in wate
isomer
One of several organic compounds with the same molecular formula but different structures and therefore different properties.
lipid
One of a family of compounds, including fats, phospholipids, and steroids, that are insoluble in water.
macromolecule
A giant molecule formed by the joining of smaller molecules, usually by a condensation reaction. Polysaccharides, proteins, and nucleic acids are macromolecules.
monomer
The subunit that serves as the building block of a polymer.
monosaccharide
The simplest carbohydrate, active alone or serving as a monomer for disaccharides and polysaccharides. Also known as simple sugars, the molecular formulas of monosaccharides are generally some multiple of CH2O.
nucleic acid
A polymer (polynucleotide) consisting of many nucleotide monomers; serves as a blueprint for proteins and, through the actions of proteins, for all cellular activities. The two types are DNA and RNA
nucleotide
The building block of a nucleic acid, consisting of a five-carbon sugar covalently bonded to a nitrogenous base and a phosphate group.
organic chemistry
The study of carbon compounds.
peptide bond
The covalent bond between two amino acid units, formed by a dehydration reaction.
phospholipid
A molecule that is a constituent of the inner bilayer of biological membranes, having a polar, hydrophilic head and a nonpolar, hydrophobic tail.
polymer
A long molecule consisting of many similar or identical monomers linked together.
polypeptide chain
A polymer (chain) of many amino acids linked together by peptide bonds.
polysaccharide
A polymer of up to over a thousand monosaccharides, formed by dehydration reactions.
primary structure
The level of protein structure referring to the specific sequence of amino acids
protein
A three-dimensional biological polymer constructed from a set of 20 different monomers called amino acids.
ribonucleic acid
(RNA)A type of nucleic acid consisting of nucleotide monomers with a ribose sugar and the nitrogenous bases adenine (A), cytosine (C), guanine (G), and uracil (U); usually single-stranded; functions in protein synthesis and as the genome of some viruses.
saturated
Pertaining to fats and fatty acids whose hydrocarbon chains contain the maximum number of hydrogens and therefore have no double covalent bonds. Saturated fats and fatty acids solidify at room temperature.
starch
A storage polysaccharide in plants consisting entirely of glucose.
steroids
A type of lipid characterized by a carbon skeleton consisting of four rings with various functional groups attached.
unsaturated
Pertaining to fats and fatty acids whose hydrocarbon chains lack the maximum number of hydrogen atoms and therefore have one or more double covalent bonds. Unsaturated fats and fatty acids do not solidify at room temperature.