Chemical Reactions and Enzymes

I. What are enzymes? Your body has lots of reactions! Enzymes: special protein catalysts that speed up specific reactions End in ASE Ex. Lactase digest lactose

The energy needed to get a reaction started Activation Energy: The energy needed to get a reaction started

III. Lower the Activation Energy Activation energy is the “start up” energy of a reaction They do not raise the temp! Increase the frequency that the reactants come together to react!

Enzymes Without Enzyme With Enzyme Free Energy Progress of the reaction Reactants Products Free energy of activation

IV. Enzymes are Specific The shape of each enzyme fits the shape of what its acting on SUBSTRATE: the reactant that connects with enzyme ACTIVE SITE: area where the substrate and enzyme meet up

V. Lock and key model Lock is the enzyme Key is the substrate The lock hole is the active site

Enzymes can only catalyze 1 reaction because they only allow substrates with one particular shape to bond oes not fit!

Factors that Affect the Enzyme Performance Temperature pH Salinity Concentration of enzyme or substrate

Temperature Enzymes are PROTEIN Heat too high they can denature

pH Enzymes work best at an ‘optimal’ pH Proteins they can denature Trypsin

Salinity Too much salt will cause the enzyme (protein) to denature, changing its shape so it will not function

Other factors Concentration of enzyme and concentration of substrate will affect how many reactions can occur. Reactions depend on the limiting factor!

Enzymes are Reusable Enzymes will speed the reaction for a substrate It will release the product and will work on another substrate

Examples Life is not possible without enzymes! !!!!!!! Lipase Protease Lactase Sucrase Amylase Life is not possible without enzymes! !!!!!!!