Questions
1. what is the difference between lactose tolerance and lactose intolerance? be specific.

The difference between lactose intolerance and it's opposite, 'lactose persistence' is the simply the ability and inability to consume lactose as an adult.

Lactose is found in dairy products. Many people develop an intolerance towards lactose as they become adults. The level is intolerance varies from person to person.

People develop lactose intolerance when the lactase enzyme is very low or not present at all in their body. The enzyme is present in small intestine and it breaks down lactose into digestible form. People with lactose intolerance view symptoms such as bloating or stomach pain.

On the other hand, many people have shown lactase persistence and are able to ingest and digest dairy products containing lactose easily. They do not have any symptoms or other problems. Lactase persistence was first seen in people who domesticated mammals such as cows, goat, buffaloes etc.

answer: substrate concentration. enzymes work best when there is a high enough substrate concentration for the reaction they catalyse.