ENZYME ACTIVITY & COLLISION THEORY

Thursday, June 11, 15

WHAT IS REACTION RATE?

Rate of Reaction - speed of a chemical reaction

Rusting Baking Explosion

Slow Fast Very fast

(how quickly a reactant is consumed as it converts into a product)

Thursday, June 11, 15

WHY DO REACTIONS OCCUR?

Particles are constantly moving - collide with each other

Hit with enough energy and in right orientation - form larger molecules/compounds

Thursday, June 11, 15

COLLISION MODELCollision Model - the more collisions, the more likely that particles have enough kinetic energy and will be oriented properly for a reaction to occur

Activation Energy - minimum energy required for a reaction to occur

Energy Needed to Start Reaction

Thursday, June 11, 15

As the number of substrate molecules increase, so does the chance of a successful reaction (collision theory)Enzyme molecules are saturated with substrate (all enzyme molecules are occupied at any given time)

⓵

⓶

⓵

⓶

EFFECT OF SUBSTRATE CONCENTRATION

Thursday, June 11, 15

⓵ ⓶

⓶

⓵ As temperature increases so does molecular motion. This increases probability of a successful reaction (collision theory)High temperature denatures the enzymes. They will no longer catalyze the reaction

EFFECT OF TEMPERATURE

Thursday, June 11, 15

Effect of pH

⓶

⓵ Pepsin functions within pH range 0.4-4. Pepsin’s optimal pH is 1.8

⓵

Trypsin functions within pH range 6-10. Trypsin’s optimal pH is 8.2

⓶

Outside of these pH ranges the enzymes will denature!

EFFECT OF PH

Thursday, June 11, 15