Enzymes 1 Flashcards
In order for a reaction to proceed spontaneously delta G must be?
Negative
What does not indicate the speed of a reaction?
Magnitude of delta G
Most spontaneous reactions are?
Slow
What us a catalyst?
Substance that speeds up chemical reaction without being used up.
What is a biological catalyst?
Enzyme - protein
What is activation energy?
Energy barrier prevents reactants becoming products instantaneously.
What are transition state species?
Energy input needed to convert reactants into usable molecular forms
How do you get reactants to overcome Activation energy barrier?
Add more energy to reactants.
How do you add more energy to reactants?
Heat - speeds all reactions, including the breakdown of structures such as mem and proteins.
How do enzymes work?
They alter the nature of transition state species - activation energy to form the transition state is much lower
How do enzymes reduce activation energy?
Reduction comes from the release of energy when enzyme binds to substrate.
free energy released when multiple weak bonds and interactions form between enzyme and substrate.
What effects binding of enzyme to a substrate?
Weak interactions
non complimentary active sites
exclusion of water
Enzymes are grouped into 6 categories, what are these?
Oxidoreductases Tranferases Hydrolases Lyases Isomerases Ligases
What do Oxidoreductases do?
Catalyse the transfer of electrons from a donor to an acceptor.
What do Tranferases do?
Catalyse the transfer of function al groups such as phosphate from one molecule to another.
