Aim: How do enzymes affect the rate of chemical reactions?

DO NOW:1. Describe the problem in the first

picture.2. Describe the

second picture.3. Define the term

rate.

Enzymes• Proteins• Enzyme names end is -ase• Act as catalysts & speed up the rate of chemical

reactions, for life processes or life activities• Never used up in a reaction, can be re-used• Very specific (shape & function)• Have active sites, to which substrates, will bind

to• Substrates are “acted upon” or changed in the

reaction (the reactants)

Enzymes

• When enzymes & substrates bind, an enzyme-substrate complex, a temporary union, forms(substrate is changed during this time)

• Reactant (s) becomes a product (s)• All organisms (animals, plants, bacteria & fungi)

depend on enzymes• Work best in specific conditions (pH, temperature) • Amount of enzyme & substrate available & enzyme

shape both affect the rate of the reaction

Lock & Key Model

Enzyme Structure

Enzyme-Substrate Complex

Digestive Enzymes

Synthesis Enzymes

Human Body Enzymes

Use of Enzymes Across Sectors

Enzyme Animation

• http://highered.mheducation.com/sites/0072495855/student_view0/chapter2/animation__how_enzymes_work.html

• http://www.kscience.co.uk/animations/anim_2.htm

Let’s Practice!