Question

What is fermentation? What are the two types of fermentation? What is the metabolic purpose of fermentation? At the molecular level, what happens during this process?

What is Lactaid? How did the addition of Lactaid affect fermentation? Why?

Answer 1

Metabolism of carbohydrates in the absence of oxygen in yeast cell, muscle or liver called fermentation.

Types of fermentation: two types,

Lactic acid and alcoholic fermentation.

The purpose of fermentation is to regenerate NAD+ from NADH, which is produced from glycolysis.

When the cell lack oxygen, such as muscle cell during excercise, produce lactate as the end product of pyruvate to regenerate NAD+ which is then used for glycolysis again. Yeast cell use Pyruvate decarboxylase and alcohol dehydrogenase to produce ethanol and NAD+.

Lactaid: Is a table contain the enzyme lactase.

Addition of Lactaid i.e lactase degraded lactose to Glucose and galactose. Which is easily absorbed by intestine of any lactose intolerance people. Otherwise such type of intestine ferment the lactose sugar. Thus Lactid reduces the fermentation rate in intestine.

In case of yeast which can't produce lactase. Addition of Lactid degrade lactose as glucose and galactose which is easily ferment by the yeast cell. In this case lactase help in fermentation or enhance it.