Exam 2 Flashcards
(63 cards)
Kinetic energy
Energy of motion
Potential energy
Energy that is stored in position or configuration
First law of thermodynamics
Energy cannot be created or destroyed, only transferred and transformed
Exothermic
Change in H is negative (releases heat)
Endothermic
Heat is used, H is positive
Entropy
The disorder of a system
Second law of thermodynamics
Total entropy always increases in a system that includes the surroundings and products of the reaction
Gibbs free energy
Amount of energy available to do work
Exergonic
G is less than zero
Endergonic
G is greater than zero
Energetic coupling
Either the transfer of electrons or the transfer of a phosphate group during exergonic and endergonic reactions
Redox reactions
Reactions that involve the loss or gain of one or more electrons
Oxidation
Loss of electrons
Reduction
Gain of electrons
Substrate
Reactant that interacts with a catalyst (such as an enzyme) in a chemical reaction.
Phosphorylation
Addition of a phosphate group to a substrate
Catalysts
Bring substrates together in a precise orientation that makes reactions more likely
Active site
Substrate bonding site. Enzymes can then help substrates collide in a precise orientation so that old bonds can break and new ones can form to generate products
Transition state
Interaction between substrate and enzyme reaches maximum
Activation energy
Energy required to strain the chemical bonds in substrates so they can achieve the transition state
Competitive inhibition
Molecule competes with the substrate for access to the enzymes active site
Allosteric regulation
Regulatory molecule binds at location other than the active site and changes the shape of the enzyme
Feedback inhibition
Using final product of reaction to inactivate one of the enzymes
Catabolic pathways
Break down molecules for sources of energy and carbon building blocks
