Warm-Up Write a short paragraph in your notes using as many of the following words as possible Monomer -Variety Polymer -Macromolecules Organic Chemistry -Large Carbon -Protein

Chemical Reactions and Enzymes

Chemical Reactions A process that changes one set of chemicals into another

Chemical Reactions A process that changes one set of chemicals into another Some occur slowly (rust on a bicycle)

Chemical Reactions A process that changes one set of chemicals into another Some occur quickly (atomic bomb)

Chemical Reactions H2O + CO2 C6H12O6 + O2 Reactants – go into the chemical reaction Products – made by the chemical reaction

Chemical Reactions Always involve BREAKING BONDS in reactants and FORMING NEW bonds in products So they also involve changes in ENERGY

ENERGY in REACTIONS Chemical reactions that release energy occur SPONTANEOUSLY Chemical reactions that absorb energy need an ENERGY SOURCE

Feeling HOT, HOT, HOT? The cellulose in your paper releases energy (burns) in the presence of oxygen. Will it light on fire now?? Only if we give it enough energy to get started…this is called the ACTIVATION ENERGY

Activation Energy The energy needed to get a reaction started.

Lowering Activation Energy Catalyst – substance that speeds up the rate of a reaction ENZYMES – proteins that act as catalysts Speed up chemical reactions that take place in cells Lower the activation energy needed to start a reaction

Lowering Activation Energy

Demonstration

How Enzymes Work Enzymes are very specific Each enzyme binds to a specific substrate (the reactant of a reaction) Enzymes are named for the substrate they bind to with –ase added to the end Amylase is the enzyme for starch called amylose Sucrase acts on the sugar sucrose Peroxidase breaks down peroxide in the body

Anabolic – Make ‘em

Catalytic – Break ‘em

Factors affecting Enzymes Anything that would affect a normal chemical reaction pH Temperature Most enzymes work best at a temperature of 37°C. Why?