Summary; section 5.5

Summary

• weaken chemical bonds for chemical reaction
• to do this, molecules need to absorb energy
• ex) add heat, weaken bonds
• heating = unnecessary reactions
• rely on catalysts
• catalyst = compounds speeding chemical reactions
• enzymes = example of catalyst
• enzymes - reaction at cell's normal temp
• lowers energy required for chemical reactions
• enzyme catalyze different reactions
• enzyme fits shape of specific reactant molecules
• specific reactant acted upon by enzyme = substrate
• substrate fit into the active site
• shapes change to fit substrate
• enzyme lower activation energy = "accepting two reactant molecules" (pg104)
• accepting into "adjacent sites"(pg104)
• holding reactant - react more easily
• enzyme also sensitive to heat or ph change

Concept Check
1. Activation energy is the amount of energy that is needed so that a chemical reaction can begin and take affect. The enyzme however, lowers the activation energy so that cells can react at normal or regular temperature
2. The substrate is fitted into the active site, or particular sites on the enzyme and the substrate lets the enzyme do it's job. By doing this, the enzyme lowers the activation energy for the chemical reaction.