Chemical Reactions & Enzymes

Chemical Reactions

• Process that changes one set of chemicals into another set

• Reactants - things that go into reaction• Products - things that come out of reaction

Chemical Reactions cont’d

• Always involve breaking bonds and forming new ones

• Example in our body– Carbon dioxide combines with water in the

bloodstream to form carbonic acid so the carbon dioxide can be taken to the lungs

Energy in Reactions

• Energy Changes– Spontaneous reactions release energy– Other reactions must have energy added because

they absorb energy– Energy is released as heat or light

• Activation energy– Amount of energy to start a reaction

Enzymes

• Catalyst - substance that speeds up rate of reaction

• Enzyme - are proteins that act as biological catalysts– Enzymes are very specific, each can catalyze only

one reaction– The enzyme name contains the name of the

reaction it acts on

Reaction pathwaywithout enzyme Activation energy

without enzyme

Activationenergywith enzymeReaction pathway

with enzyme

Reactants

Products