The answer is Model. Hope this helps!!
Function of an enzyme is to lower reaction's activation energy and to increase speed of a reaction, but to make it happen, enzyme and substrate must fit spatially. The shape of an enzyme is essential to make enzyme-substrate complex - if active site of an enzyme doesn't fit to substrate, there won't be a enzyme-catalised reaction.
James Watson and Francis Crick
RICE is the staple of South Korean diet while CORN is a staple of the US diet.
These preferences for food in these two countries are influenced by historical and social factors.
Most of the food in South Korea are usually prepared from rice while in the US most of the staple food are prepared from corn.
