mechanism of enzyme action

Question 1

explain the lock and key model of enzyme action

Answer 1

• suggests that active site has a rigid shape determined by tertiary structure so is only complementary to 1 substrate, formation of ESC’s therefore lowers activation energy
• bonds in EPC are weak, so product desorb

Question 1

explain the induced fit model of enzyme action

Answer 1

• shape of active site is not directly complementary to substrate and is flexible
• conformational change enables ESC’s to form when substrate absorbs
• this puts strain on substrate bonds, lowering activation energy, bonds in enzyme product complex are weak, so product desorbs