CBI Definitions Flashcards
(89 cards)
System
The system is simply the set of (biochemical) reactions and interactions we are interested
in studying within a particular boundary. For example, this might be the reactants and
products in a reaction.
Surroundings
This is simply everything else that is outside the system of interest that is in contact with
the boundary of the system, usually the rest of the universe.
Boundary
This is conceptually where the system and the surroundings meet
Thermodynamic temperature
Absolute measure of energy (Kelvin(K)) inside an object
Heat
The process of reaching equilibrium when two objects of different temperatures meet
Enthalpy
Internal energy of a system + pressure x volume
(kinetic + chemical energy)
Entropy
Measure of the number of ways in which energy is distributed across and within components of a
system - thermodynamic measure of system randomness
(thermal energy not able to do work)
Gibb’s Energy
A rationalisation of the relationship between energy available to do work and unavailable which defines spontaneity
Exergonic
Gibb’s energy decreases over the course of the reaction
Endergonic
Gibb’s energy increases over the course of the reaction
Transition state
This is the species of highest energy along a reaction pathway. Transition states occur at
energy maxima and cannot be isolated. In diagrams, the transition state is
commonly designated with a double-dagger symbol ‡.
Activated complex
The range of configurations that occur as a reaction proceeds that are near the transition
state are collectively known as the activated complex.
Activation energy
This is the energy in excess of that possessed by the reactant(s) that is required for the
reaction to proceed. It is denoted with the symbol Ea.
Addition reactions
A chemical reaction between two (or more) molecular species that results in a single
reaction product that contains all the reactants. Addition reactions occur at multiple
bonds in molecules.
Elimination reactions
The reverse of an addition reaction, whereby two components (atoms or functional
groups) are lost. Elimination reactions result in the formation of multiple bonds in
molecules.
Substitution reactions
A chemical reaction in which one atom or functional group in a molecule is replaced by
another.
Rearrangement reactions
The internal connectivity of the atoms within a molecule is changed.
Redox reactions
A specific type of chemical reaction where electrons are transferred from one reactant to
another.
Oxidation
The loss of electrons or increase in oxidation state
An oxidising agent gains electrons during a redox reaction and is therefore reduced during
Reduction
The gain of electrons or decrease in oxidation state
A reducing agent loses electrons during a redox reaction and is therefore oxidised
Aldose
Carbohydrate chain with C=O on the end
Ketose
Carbohydrate chain with C=O in the middle
Hemiacetal
Cyclisation of aldose
Proteinogenic
This refers to substances or molecules that contribute to the creation or synthesis of proteins. (Typically amino acids)