11/4/2014 Current event- moved to Thursday There will be 3 current events… PPP on review chemical reactions including enzyme’s role. Presentations on “effects of different environmental conditions on enzymes” Exit slip on enzymes. HW: Enzyme graphing worksheet next class Unit test 11/11/2014- review power points on- line NOW AND go online and fill in the google form about group work!

Chemical Reactions A Review

Chemical Energy Potential energy Energy stored in the bonds Can be converted into kinetic energy (heat, light, sound, movement etc.)

Heat Energy Is how much the atoms/molecules are moving More heat/temperature = more movement

All reactions require an initial input of energy to get reaction started Called the activation energy i.e. lighting the fuse on a bomb

Why? It takes energy to get bonds to break More energy = moving faster = molecules can break apart

I.e. It takes energy to split lactose and water Energy is released when new bonds are formed Energy Energy

Exothermic vs. Endothermic Exothermic Net effect is energy released from reactants The products have less energy than the reactants Energy/heat is released I.e. TNT

Endothermic vs. Exothermic Endothermic Net effect is energy into the products The products have MORE potential energy than the reactants These reactions absorb energy/heat i.e. a ice pack

Potential Energy Diagram with enzyme catalyzed reaction

Let’s review! 1. what is a way to break a bond? ▫Heat 2. What does it really mean to heat something? ▫Make the molecules move around faster. ▫Demo! ▫NOTE: energy goes in to BREAK a bond 3. After a bond breaks…then what? ▫Bonds form between molecules to make stable. Mostly new products. ▫NOTE: Energy is released when new bonds form.