Lactase & the Mechanism of Lactose Intolerance

The video explains lactose, a disaccharide found in milk, and its metabolism in infants through the enzyme lactase. It discusses how lactase breaks down lactose into glucose and galactose, which are used for energy and biosynthesis. The video also covers lactose intolerance, a condition where lactase levels drop, leading to lactose accumulation in the intestines. This can cause symptoms like flatulence and diarrhea due to bacterial fermentation and osmotic imbalance.

What are the two sugars that make up lactose?

• Fructose and sucrose

• Galactose and sucrose

• Glucose and galactose

• Glucose and fructose

What is the primary function of the enzyme lactase?

• To convert lactose into glucose and galactose

• To convert glucose into energy

• To convert galactose into glucose

• To convert lactose into fructose

What percentage of adults are estimated to be lactose intolerant?

• 25%

• 80%

• 50%

• 65%

In lactose-intolerant individuals, what happens to lactose in the intestines?

• It is fully absorbed

• It is converted into glucose and galactose

• It is excreted unchanged

• It accumulates and is metabolized by bacteria

What is one of the gases produced by bacterial metabolism of lactose?

• Helium

• Oxygen

• Nitrogen

• Carbon dioxide

What symptom is caused by the increased osmolarity in the intestines due to lactose accumulation?

• Headache

• Nausea

• Diarrhea

• Constipation

What is a common symptom of lactose intolerance due to bacterial gas production?

• Rash

• Dizziness

• Flatulence

• Vomiting