EnzymesBiology 3 Kawashima

What is a catalyst?

An agent that speeds up a chemical reaction without being consumed by

the reaction.

What is an enzyme?

A catalytic protein that speeds up the construction (anabolism) or

breakdown (catabolism) of molecules

ΔG = -7 kcal/mol

Activation Energy

Energy required for the reaction to proceed.

This energy investment is used to “contort” the reactants into its

transition state

How enzymes lower the energy barrier

• Provides template for proper orientation of substrates for the reactionTemplate

• Alters conformation of substrate towards its transition stateContort

• Provides a more conducive environment (pH) for reaction

Microenvironment

• Active site may bond with substrate to form an intermediate Participate

Each type of enzyme has a specific set of optimum conditions