Glossary Flashcards
Accuracy
The degree to which a result conforms to the correct standard/value.
Precision
The degree to which results align with each other.
Reliability
The degree of certainty that a result is accurate.
Validity
Whether or not an experiment reflects or tests the research question.
Bias
Difference between the average of a large set of measurements and the true value.
Uncertainty
The degree of variation from one value to the next.
Personal error
Result from mistakes or misinterpretations of readings by the experimenter.
Systematic error
Errors in measurement varied by the same proportion from the true value (includes errors inherent to the experiment).
Random error
Errors in measurement that differ in proportion each time the experiment is conducted.
Pressure
The force of the gas on the walls of the vessel, per unit of surface area.
Chemical energy (enthalpy)
The energy contained within the various electric forces within and between species.
Thermal energy
Kinetic energy that manifests in the speed of randomly moving particles.
Activation energy (Ea)
The minimum energy required to commence a reaction.
Endothermic reaction
Has a net absorption of energy by the chemicals.
Exothermic reaction
Has a net release of energy by the reactants.
Fuel
A substance that can be reacted with other substances leading to the release of energy that can be harnessed for a specific purpose.
Greenhouse gasses
Gasses that absorb infra-red radiation, which warms the planet.
Renewable
Can be replenished at a rate quicker than it is consumed.
Viscosity
How resistant to flow a substance is.
Hygroscopic
Attracts water from the atmosphere.
Biogas
Fuel produced by the anaerobic breakdown of organic matter.
Bioethanol
Fuel produced by the fermentation of glucose in organic matter.
Biodiesel
Fuel produced by the esterification of the fats and oils in organic matter.
Complete combustion
Reaction of a substance with oxygen to produce CO2 and H2O.
Incomplete combustion
Partial burning of a substance to produce carbon monoxide (or solid carbon) and water.
Reduction
Gain of electrons.
Oxidation
Loss of electrons.
Conjugate redox pair
Reducing agent and its corresponding oxidizing agent.
Galvanic cell
An electrochemical cell in which chemical energy from spontaneous redox reactions is converted into electrical energy.
Standard half cell
A cell consisting of both members of the conjugate redox pair and an electrode at standard conditions.
Spontaneous reactions
Reactions that occur without an external energy source.
Direct redox reactions
Reactions where the chemical species react in the same vessel.
Indirect redox reactions
Reactions where chemical species react together in separate vessels.
Fractional distillation
The separation of a mixture into its component by heating them to a temperature at which one or more fractions of the mixture will vaporize.
Fuel cell
Electrochemical cell that continuously converts chemical energy into electrical energy by a redox reaction.
Porous electrode
A feature of fuel cells which maximises the ability for gaseous reactants to come into contact with the electrolyte.
Collision theory
For a chemical reaction to occur, the reactant particles must collide with sufficient energy and with the correct orientation.
Catalyst
A substance which increases the reaction rate without being consumed.
Heterogenous catalyst
A catalyst whose physical state differs from the phase of the reactants.
Homogenous catalyst
Catalyst whose physical state is the same as the phase of the reactants.
Transition state
The state corresponding to the highest energy point o an energy profile diagram during which bond breaking and forming is occurring.
Dynamic equilibrium
System in which the forwards and backwards reactions are occurring at the same rate.
Electrolytic reaction
Non-spontaneous redox reaction which requires energy to proceed.
Overpotential
The difference between the calculated potential required and actual potential required to facilitate an electrolytic reaction.
Primary cells
Non-rechargeable electrochemical cells.
Secondary cells
Rechargeable electrochemical cells.
Recharge
Conversion of electrical energy into chemical energy with the application of electricity.
Discharge
Conversion of chemical energy into electrical energy with the spontaneous release of electricity.
Batteries
Devices consisting of cells which convert chemical energy to electrical energy.
Saturated hydrocarbons
Molecules that have only single carbon-carbon bonds.
Unsaturated hydrocarbons
Molecules that have at least one double or triple carbon-carbon bond.
Substituents
Single atoms or groups of atoms which are attached to the parent carbon chain.
Chiral compounds
Compounds which cannot be superimposed on their mirror image.
Chiral centre
An atom with four different substituent groups.
Flash point
Lowest temperature at which an organic compound gives off sufficient vapor to ignite in air.
Volatility
Tendency to be vaporized.
Addition reaction
Reaction where one molecule combines with another to form a larger molecule with no other products.
Condensation reaction
Reaction where two molecules combine to form a larger organic molecule and a smaller molecule (usually water).
Equivalence point
Where neither reactant is in excess.
Esterification
Reaction which produces an ester.
Hydrolysis
Reaction where water is used to break the bonds of a substance.
Substitution reaction
Reaction where an atom, or group of atoms, is replaced by another atom or group of atoms.
Base peak
Peak formed from ion fragments with the greatest relative intensity.
Molecular ion peak
Peak formed from the un-fragmented form of a molecule (the parent ion).
Spin state
Orientation of a nucleus when being placed in an external magnetic field.
Stationary phase
Solid to which the components of a sample adsorb.
Mobile phase
Solution which flows through the stationary phase carrying components of a sample with it.
Adsorbtion
Where a component adheres to the stationary phase.
Desorption
When a component is released from the stationary phase.
Eluent
Combination of the mobile phase AND sample that moves through the HPLC column.
Standard solution (titrant)
Solution of accurately known concentration.
Primary standard
Substance used to make a primary standard solution.
Analyte
Substance being analyzed in a titration reaction.
Titre
Volume of the solution delivered from the burette to reach the endpoint.
Aliquot
Portion of the analyte solution which is to be analyzed.
Concordant titres
Volume of three or more titres that fall within approximately 0.1mL of each other.
Endpoint
The point at which a colour change occurs during a titration.
Essential amino acids
Amio acids that cannot be synthesized by the human body and therefore must be included in the diet.(9).
Primary structure
The sequence of amino acids which make up a polypeptide.
Secondary structure
The alpha-helix or beta-pleating caused by hydrogen bonding between C=O and N-H groups within the peptide link of different sections of the chain.
Tertiary structure
Three-dimensional shape of the protein caused by further hydrogen bonding, dipole-dipole interactions, ionic interactions, covalent crosslinks, and dispersion forces.
Quaternary structure
Multiple polypeptide chains with cross-linking to fit a specific shape/purpose.
Dipeptide
Product of a condensation reaction between 2+ amino acids.
Polypeptide
Product of a condensation reaction between multiple amino acids.
Metabolism
Breakdown of food and its transformation into energy.
Denaturation
Process where proteins lose their quaternary, tertiary and/or secondary structure due to factors such as pH and temperature change.
Active site
Region of an enzyme where the substrate molecule binds to the enzyme and undergoes a chemical reaction.
Substrate
Molecule which an enzyme acts upon.
Protonation
Gain of a proton.
Deprotonation
Loss of a proton.
Coenzyme
Organic molecule that attaches to the active site of an enzyme and changes the surface shape to enable that substrate to bind.
Essential vitamins
Vitamins that cannot be produced by the human body and therefore must be consumed (13).
Monosaccharide
Smallest building block of carbohydrates consisting of only one sugar molecule.
Disaccharide
Carbohydrate formed from a condensation reaction between two monosaccharides and joined by a glycosidic linkage.
Polysaccharide
Complex carbohydrates formed from the condensation of multiple monosaccharides that are joined by glycosidic links.
Aspartame
Powerful artificial sweetener 200 times sweeter than sucrose.
Starch
Polysaccharides made up of multiple a-glucose monosaccharides.
Amylopectin
A highly branched form of starch.
Amylose
Tightly coiled, unbranched form of starch.
Cellulose
Polysaccharide composed of b-glucose that is indigestible to humans.
Glycogen
Highly branched polysaccharide made up of glucose monosaccharides that is used by animals for energy storage.
Amylase
Enzyme that catalyzes the hydrolysis of starch.
Essential fatty acids
Fatty acids that cannot be produced by the human body and therefore must be included in the diet. (2).
Fats
Lipid molecules that are solid at room temperature.
Oils
Lipid molecules which are liquid at room temperature.
Lipids
Fats and oils.
Fatty acid
Carboxylic acid with a long hydrocarbon chain.
Omega carbon
Carbon atom of the methyl group at the end of the carbon chain (opposite end to the carboxyl group) in a fatty acid.
Omega-3 fatty acid
Fatty acid with a carbon-carbon double bond on the third carbon from the omega end.
Omega-6 fatty acid
Fatty acid with a carbon-carbon double bond on the sixth carbon from the omega end.
Monounsaturated fatty acid
Fatty acid which contains only one carbon-carbon double bond.
Polyunsaturated fatty acid
Fatty acid which contains more than one carbon-carbon double bond.
Saturated fatty acid
Fatty acid which contains only carbon-carbon single bonds.
Oxidative rancidity
The breakdown of unsaturated fatty acids into aldehydes and ketones in the presence of oxygen.
Antioxidant
Oxidized in preference to another substance, preventing it from going rancid.
