What is the enzyme lock and key mechanism?

Enzymes are proteins and they have specific shapes.Do you know what active site is? Region where the chemical reaction happen, this is a different shape on different enzymesDo you know what substrate is? Substance which enzyme acts onLock and key mechanism- this is the theory of how enzymes are specific to their substrates (specific shape of active site only fits a certain substrate) Enzymes only catalyse one reaction!DRAW ENZYME WITH SUBSTRATE WITH COMPLEMENTARY SHAPE AND ONE WITH WRONG SHAPESUBSTRATE WITH COMPLEMENTARY SHAPE FITS INTO ACTIVE SITE AND CAN BE BROKEN DOWN BY ENZYMEThis specific fit is like a LOCK AND KEY, hence the name and this is a good way to remember it.DRAW SUBSTRATE BROKEN DOWN AND PRODUCTS RELEASED FROM ACTIVE SITE NOTICE ENZYME IS UNCHANGED, AND CAN BE USED AGAINExtra question: What is enzyme substrate complex?