Glossary

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Glossary Entries

Word(s)	Definition	Image	Caption	Link	Source
organic chemistry	study of the chemistry of the carbon compounds
organic molecule	Compound that contains carbon and hydrogen
molecular formula	shows the type and number of atoms in a molecule
structural formula	shows all atoms and the bonds attaching them
Lewis Structure	shows all atoms and electrons (bonding and nonbonding) attaching them
Condensed structural formulas	an abbreviated formula that shows all the atoms in a molecule, without showing all of the bonds
Skeletal Structures (or line-angle structures)	shows all the bonds between carbon atoms, but omits some atom labels
hydrocarbons	Organic molecules containing only carbon and hydrogen atoms
alkane	hydrocarbons with only C–C and C–H single bonds.
saturated	maximum number of H atoms
conformers	different rotational forms of a molecule
Structural (or constitutional) isomers	molecules with the same molecular formula but a different connectivity.
cycloalkane	Three or more carbon atoms arranged in a ring with only C-C and C-H bonds
substituents	groups that replace at least one H in order to branch from the alkane chain.
alkenes	Molecules that contain a carbon-carbon double bond (C=C) and general molecular formula: CnH2n
parent chain	longest continuous chain of carbon atoms
diene	molecule that contains two C=C
polyene	molecule that contains  more than two C=C
cycloalkene	cyclic molecule that contains a C=C
alkyl halide	organic molecules where a halogen (F, Cl, Br, or I) has replaced a hydrogen
geometric (cis-trans) isomers	molecues that have different arrangements because of restricted rotation around a  carbon-carbon double bond (or ring)
alkynes	Molecules that contain a carbon-carbon triple bond (C≡C) and general molecular formula: CnH2n-2
aromatic	class of cyclic compounds that contain a benzene ring				Cacycle, Benzene Structure, CC BY-SA 3.0, via WikiMedia Commons
functional group	atoms bonded in a specific way that represents a specific class of organic compounds
alcohols	molecules that contain the hydroxyl (–OH) functional group
primary (1^o) alcohol	alcohols that have one alkyl group attached to the carbon where the functional group is bonded
secondary (2^o) alcohol	alcohols that have two alkyl groups attached to the carbon where the functional group is bonded
tertiary (3^o) alcohol	alcohols that have three alkyl groups attached to the carbon where the functional group is bonded
diol	molecules that contain two hydroxyl (–OH) functional groups
triol	molecules that contain three hydroxyl (–OH) functional groups
polyol	molecules that contain many hydroxyl (–OH) functional groups
phenol	molecules that contain the hydroxyl (–OH) functional group directly attached to a benzene ring
thiol	molecules that contain the sulfhydryl (–SH) functional group
ether	molecules contain the R–O–R’ functional group
amine	Molecules derived from ammonia (NH3), where one or more hydrogen is replaced with a carbon
primary (1^o) amine	amine that has one alkyl group attached to the nitrogen of the functional group
secondary (2^o) amine	amine that has two alkyl groups attached to the nitrogen of the functional group
tertiary (3^o) amine	amine that has three alkyl groups attached to the nitrogen of the functional group
carbonyl group	represents a carbon-oxygen double bond (C=O)
aldehyde	molecules that contain a hydrogen directly bonded to the carbon of a carbonyl group; condensed notation: R–CHO
ketone	molecules that contain two carbon groups directly bonded to the carbon of the carbonyl group; condensed notation: R–CO–R'
carboxylic acid	molecules that contain a hydroxyl (–OH) directly bonded to the carbon of a carbonyl group; condensed notation: R–COOH
esters	molecules that are derivatives of carboxylic acids, formed by replacing the H of the carboxyl group with an alkyl (carbon) group; condensed notation: R–COOR'
amide	molecules that are derivatives of carboxylic acids, formed by replacing the OH of the carboxyl group with ammonia or an amine; condensed notation: R–CONH2'
Redox (oxidation-reduction) reaction	reactions involving a transfer of electrons
oxidation	loss of electrons; or in organic compounds, involves an increase in oxygen and/or decrease in hydrogen
reduction	gain of electrons; or in organic compounds, involves an decrease in oxygen and/or increase in hydrogen
reducing agent	undergoes oxidation; responsible for something else getting reduced
oxidizing agent	undergoes reduction; responsible for something else getting oxidized
addition reaction	reaction in which an atom or molecule is added to an unsaturated molecule, making a single product
hydrogenation reaction	addition of H2 to an alkene in the presence of a metal catalyst to produce an alkane
halogenation reaction	addition of a halogen to an alkene to produce a di-substituted alkyl halide
hydrohalogenation reaction	addition of a hydrogen halide to an alkene to produce a mono-substituted alkyl halide
hydration reaction	addition of water to an alkene in the presence of an acid catalyst to produce an alcohol
elimination reaction	reaction that involves the removal of adjacent atoms from a molecule to form an alkene
dehydration reaction	elimination reaction where water is removed from the molecule to form an alkene
dehydrogenation reaction	elimination reaction where molecular hydrogen is removed from the molecule to form an alkene
dehalogenation reaction	elimination reaction where a halogen is removed from the molecule to form an alkene
polymer	large molecule formed of repeating smaller units that are covalently bonded to one another in a repeating pattern
monomer	smaller units that make up a polymer
condensation reaction	reaction that involves two molecules combining to form one larger organic molecule and water.
esterification	condensation reaction that occurs when a carboxylic acid and alcohol combine to form an ester and water				" Condensation Reactions" by LibreTexts is licensed under CC BY-NC .
amidation	condensation reaction that occurs when a carboxylic acid and amine (or ammonia) combine to form an amide and water				" Condensation Reactions" by LibreTexts is licensed under CC BY-NC .
hydrolysis reaction	reaction that involves water reacting with an organic molecule to  break it down to form two or more smaller organic molecules; opposite of condensation				FrozenMan, CC BY-SA 4.0, via Wikimedia Commons
saponification	alkaline hydrolysis of an ester resulting in an alcohol and fatty acid salt (ionic compound of the conjugate base)				The original uploader was Rhadamante at French Wikipedia., CC BY-SA 3.0, via Wikimedia Commons
carbohydrates	Sugars composed of carbon, hydrogen and oxygen that provide energy when consumed.
monosaccharides	simplest carbohydrates that cannot be broken down to smaller carbohydrates; general formula: Cn(H2O)n
disaccharides	carbohydrate consisting of two monosaccharide units chemical combined through a condensation reaction
oligosaccharide	carbohydrate consisting of 3-9 monosaccharide units chemical combined through a condensation reaction
polysaccharide	carbohydrate consisting of 10 or more monosaccharide units chemical combined through a condensation reaction
chiral	objects/molecules that have nonsuperimposable (not identical) mirror images
chiral center	tetrahedral carbon bonded to four different atoms or group of atoms.
achiral	objects/molecules have superimposable (identical) mirror images
stereoisomers	molecules that have the same molecular formula and same connectivity/bonding between the atoms.
enantiomers	stereoisomers with nonsuperimposable mirror images.				FlyScienceGuy, CC BY-SA 4.0, via Wikimedia Commons
diastereomers	stereoisomers that are not enantiomers (not exact mirror images)				FlyScienceGuy, CC BY-SA 4.0, via Wikimedia Commons
aldose	monosaccharide that contains an aldehyde group
ketose	monosaccharide that contains a ketone group
sugar acid	product of the oxidation of a monosaccharide
sugar alcohol	product of the reduction  of a monosaccharide
pyranose	six-membered ring (five carbon atoms and an oxygen) formed from aldoses
furanose	five-membered ring (four carbon atoms and an oxygen) formed from ketoses
epimers	diastereomers that differ only at one chiral carbon
anomeric carbon	carbon of the carbonyl group
anomers	diastereomers that differ only at the anomeric carbon
glycosidic bond	connects two molecules to one another through a condensation reaction
lipid	class of biomolecules defined by low solubility in water and high solubility in nonpolar, organic solvents
fatty acids	long-chained carboxylic acids with properties similar to alkanes.
amphipathetic	contain both polar and nonpolar parts
monounsaturated fatty acid	fatty acids that contain only one carbon–carbon double bond
polyunsaturated fatty acid	fatty acids that contain more than one carbon–carbon double bond
saturated fatty acid	fatty acids that contain only carbon–carbon single bonds
triacylglycerol (triglyceride)	fats or oils; produced by the esterification of the hydroxyl groups of glycerol and the carboxyl groups of three fatty acids				Hbf878, CC0, via Wikimedia Commons
wax	lipid produced by the esterification of one fatty acid and a long-chain alcohol each containing 14 to 30 carbons
glycerophospholipids (or phospholipids)	lipids that have a glycerol backbone with two fatty acids linked to it through an ester bond and a third group which forms a phosphoester bond with an amino alcohol.				Clbt88 at English Wikibooks, Public domain, via Wikimedia Commons
sphingolipid	phospholipids that contain an 18-carbon unsaturated amino alcohol called sphingosine, instead of glycerol.				Karol Langner at en.wikipedia, Public domain, via Wikimedia Commons
sphingosine	an amino alcohol found in all sphingolipids				Ed (Edgar181), Public domain, via Wikimedia Commons
glycolipids	lipids that  contain a carbohydrate.
cerebrosides	glycolipids with a monosaccharide.				Epithelyann, CC BY-SA 4.0, via Wikimedia Commons
steroids	lipids that do not contain fatty acids; contain a steroid nucleus with four fused rings
fat	consist of triglycerides made up of mostly saturated fatty acids; exist as a solid or semisolid at room temperature.
oil	consist of triglycerides made up of mostly unsaturated fatty acids; exist as a liquid at room temperature
osmosis	occurs when water travels across the cell membrane (from a lower to a higher solution concentration) to equalize solute concentrations inside and outside of a cell
isotonic solutions	solute concentration inside and outside of the cell are equal
hypotonic solutions	solute concentration outside of the cell is lower than that inside of the cell
hemolysis (or lysis)	swelling; water flows into the cell to dilute the concentration until they are equalized
hypertonic solution	solute concentration outside of the cell is higher than that inside of the cell
crenation	shrinking/shriveling; water flows out of the cell to dilute the concentration until they are equalize
diffusion	movement of solute molecules from an area of high solute concentration to a low concentration
passive (or simple) diffusion	small molecules and nonpolar molecules use this process to move across the semipermeable membrane; no energy required
semipermeable	meaning that some things can enter, and some things cannot
facilitated transport	occurs when small polar molecules and ions pass through a channel formed by integral membrane proteins; no energy required
active transport	occurs when ions and small polar molecules move across the membrane in the opposite direction of diffusion (from low to high concentration); energy is required
essential amino acids	must be consumed because the body cannot make them.
amino acids	protein building blocks that contain an amino and carboxylic acid group				Benjah-bmm27, Public domain, via Wikimedia Commons
zwitterion	form of an amino acid that contains the protonated amine and carboxylat e; typically occurs at neutral pH
protein	biologically active polypeptide containing 50 or more amino acids
peptide	compound containing amino acids joined by a peptide bond
denaturation	process that disrupts the stabilizing attractive forces in the secondary, tertiary, and quaternary structures
dipeptide	peptide containing only two amino acids
polypeptide	peptide containing many amino acids
enzyme	biological catalyst;biologically active globular proteins that accelerate chemical reactions.
substrate	reactant in a chemical reaction (typically refers to enzyme-catalyzed reactions)
cofactor	inorganic substances that serve as non-protein helpers
conenzyme	organic substances , derived from vitamins, that serve as non-protein helper
enzyme–substrate (ES) complex	interaction of the enzyme with the substrate; intermediate of an enzyme-catalyzed reaction
lock-and-key model	active site that has a rigid, inflexible shape that is an exact complement to the substrate
induced-fit model	active site that is flexible and undergoes a conformational change, adjusting to the shape of the substrate when the substrate interacts with the enzyme.
inhibitor	Molecules that cause enzymes to lose activity by preventing the active site from interacting with substrate to form the ES complex
reversible inhibition	occurs when the inhibitor causes a temporary loss of activity
competitive inhibitors	reversible inhibitors that have structures similar to that of the substrate that compete with a substrate for the active site
noncompetitive inhibitors	reversible inhibitors that do no have structures similar to that of the substrate and do not compete with a substrate for the active site
irreversible inhibition	occurs when the inhibitor causes a permanent loss of activity; forms a covalent bond with an amino acid side chain in the enzyme’s active site
nucleic acids	biomolecules composed of nucleotides
nucleoside	sugar/base combination between a pentose and a nitrogen containing purine or pyrimidine base
nucleotide	combination between a pentose, a nitrogen containing purine or pyrimidine base, and phosphate; building blocks of nucleic acids
transcription	a segment of DNA is used to produce RNA; first step of making a protein from DNA is to make a copy of the gene from the DNA
messenger RNA (mRNA)	codes for proteins
ribosomal RNA (rRNA)	component of ribosomes
transfer RNA (tRNA)	adapter molecule that brings the amino acid to the ribosome
replication	process of making new copies of DNA
template strand	DNA sequence that is transcribed to make RNA
translation	process in which information in RNA is translated into a protein sequence
codon	triplets sequence of nucleotides in mRNA;  transcribed from DNA contains a sequence of bases specifying the protein to be made				Thomas Splettstoesser  (www.scistyle.com), CC BY-SA 4.0, via Wikimedia Commons
genetic code	assigns all 20 amino acids to codons of mRNA				Sarah Greenwood, CC BY-SA 4.0, via Wikimedia Commons
mutation	change in a DNA nucleotide sequence
substitution (mutation)	a different nucleotide is  substituted				Hullo97, CC BY-SA 4.0, via Wikimedia Commons
insertion (mutation)	a different nucleotide is  substituted				Hullo97, CC BY-SA 4.0, via Wikimedia Commons
substitution (mutation)	the addition of a new nucloetide				Hullo97, CC BY-SA 4.0, via Wikimedia Commons
deletion (mutation)	the loss/removal of a nucloetide				Hullo97, CC BY-SA 4.0, via Wikimedia Commons
mutagen	chemical or physical agents that cause mutations
metabolism	chemical reactions occurring in the body during the break down or building up of molecules
metabolic pathway	series of steps in the chemical reactions in biological systems
catabolic pathway	chemical reactions that convert larger molecules into smaller molecules;energy is released				CNX OpenStax, CC BY 4.0, via Wikimedia Commons
anabolic pathway	chemical reactions that convert smaller molecules into larrger molecules;energy is absorbed				CNX OpenStax, CC BY 4.0, via Wikimedia Commons
cellular respiration	biochemical process in which energy is transferred from carbohydrates and fats (high potential energy molecules) to ATP
adenoside triphosphate (ATP)	energy currency of the cell; nucleotide; undergoes hydrolysis to ADP (low energy) during which energy is released.				NEUROtiker, Public domain, via Wikimedia Commons
digestion	stage I of catabolism where food molecules are broken down by hydrolysis reactions into the individual monomer units; occurs in the mouth, stomach, and small intestine
glycolysis	catabolic process in which glucose is converted into pyruvate via ten enzymatic steps				Thomas Shafee, CC BY-SA 4.0, via Wikimedia Commons
aerobic conditions	with oxygen
anaerobic	without oxygen
citric acid cycle (or  Krebs cycle or the tricarboxylic acid cycle)	series of reactions that degrade the two-carbon acetyl groups from acetyl CoA into carbon dioxide while generating the high-energy molecules NADH and FADH2.				Narayanese, WikiUserPedia, YassineMrabet, TotoBaggins, CC BY-SA 3.0, via Wikimedia Commons
beta-oxidation (ß-oxidation)	stage II of catabolism where fatty acids are converted to acetyl CoA
reducing sugar	carbohydrate that can act as a reducing agent
Benedict's test	qualitative test to determine whether a carbohydrate is a reducing sugar
pyruvate	result of the breakdown of glucose during glycolysis				Pyruvic-acid-2D-skeletal.png: Benjah-bmm27derivative work: Kpengboy (talk)further derivative work GKFXtalk, Public domain, via Wikimedia Commons

 

 

This glossary content and images were created by Tanesha Osborne (except where noted otherwise). This work is licensed under a Creative Commons Attribution 4.0 International License (except where noted otherwise).