9/23 Flashcards
Hydronium
H3O(+)
Hydroxide
OH(-)
Equilibrium
Forwards and reverse reaction are occurring at the same rate (but not necessarily the same amounts)
pH
The concentration of hydronium ions
Superposable
When you superimpose one thing on another and it is exactly the same
Chiral
Superimpose mirror images on each other and they are not the same
Isomer
Same molecular formula but different arrangement of atoms
What are the 2 major types of Isomers?
- constituational: same molecular formula but different connectivity
- stereoisomer: same connectivity but different arrangement of atoms in space
Stereoisomers
- enantiomer: mirror images of each other
- diastereomers: not mirror images of each other
Biological importance of Chirality
The binding specificity of a chiral receptor site for a chiral molecule is usually favorable in one way
Potential energy
Stored energy
Kinetic energy
Energy of motion
What are enzymes?
Organic catalysts- reduces activation energy and can be used over and over again
Activation energy
Energy needed to start the reaction
Models of enzymes
Lock and Key model: the shape of the enzyme never changes and enzyme can only work on one substrate
Induced fit model: the substrate induces enzyme to change shape and upon release the enzyme returns to its original shape
Active site
Where enzyme and substrate meet
Substrate
What the enzyme is working on
Enzyme substrate complex
When the enzyme and substrate are together
Spontaneous reaction
The amount of energy in products is lower than the amount of energy in reactants (released energy= exergonic reaction)
Gibbs Free E
Energy that can be used to do work (products-reactants) normally a negative #
Non spontaneous reaction
Energy of products is greater than the energy of the reactants (Gibbs free E = positive #)
Endergonic reaction
Not spontaneous, needs to be couples with exergonic reaction (energy released from exergonic reaction needs to be greater than energy required for an endergonic reaction)
ATP
Molecule that carries energy
Coupling
Energy from an exergonic reaction is used to help an endergonic reaction occur —> entropy is always increasing
Is there a difference in free E between catalyzed and uncatalyzed reactions?
No! Net energy is always the same, activation energy may be different however
Transition state
State in which substrate has the highest potential E
Mechanisms
- bring substrates into close proximity
- orient substrates into proper direction
- provide suitable environment needed (works better in acidic/basic environment)
Cofactors
Minerals, binds to enzyme and helps configure enzyme into correct shape
Coenzymes
Vitamins
Competitive inhibition
Competes for active site, if inhibitor binds, then substrate cannot bind
Non competitive inhibition
Inhibitor that binds to a site other than the active site (allosteric site)–> changes shape of enzyme —> enzyme is ineffective
-the substrate can still enter the active site but nothing will happen
Allosteric activation
Changing enzyme from inactive to active state
Allosteric inhibition
Changing enzyme from active to inactive state
Suffix of Enzymes
-ase, like peroxidase or sucrase
