FOCUS ON: Enzymes and Digestion

Part 1 - Keywords:

1. Amylase

2. Proteases

3. Lipases

4. Digestive Enzymes

5. Carbohydrases

6. Starch

7. Amino Acids

8. Lipids

9. Glycerol

10. Bile

Part 2 - Key Facts:

Digestive Enzymes:

• Enzymes in the digestive system break down food into small, soluble molecules for absorption into the bloodstream.

• Carbohydrases convert carbohydrates into simple sugars.

• Amylase, a carbohydrase, specifically breaks down starch.

• Proteases break down proteins into amino acids.

• Lipases break down lipids (fats) into glycerol and fatty acids.

Products of Digestion:

• The products of digestion are essential for building new carbohydrates, lipids, and proteins.

• Glucose, a product of digestion, is utilised in cellular respiration.

Bile:

• Bile is produced in the liver and stored in the gall bladder.

• It is alkaline to neutralise stomach acid and emulsifies fat, forming small droplets to increase the surface area.

• Alkaline conditions and a large surface area enhance the rate of fat breakdown by lipase.

Part 3 - Quick Quiz:

1. What is the role of amylase in digestion?

   a) Breaks down lipids

   b) Converts starch into simple sugars

   c) Breaks down proteins

   Answer: b) Converts starch into simple sugars

2. What do lipases break down?

   a) Carbohydrates

   b) Proteins

   c) Lipids (fats)

   Answer: c) Lipids (fats)

3. What is the function of bile in digestion?

   a) Increases acidity

   b) Emulsifies fat and neutralises acid

   c) Converts proteins into amino acids

   Answer: b) Emulsifies fat and neutralises acid

Part 4 - Going Further:

Question: Explain how the products of digestion contribute to the building of new molecules and energy production in the body.

Answer: The products of digestion, such as amino acids, glycerol, and simple sugars, are used to synthesise new carbohydrates, lipids, and proteins. Additionally, glucose from digestion is crucial for cellular respiration, providing energy for various cellular activities.

Part 5 - Revision Tips: Focus on understanding the specific roles of amylase, proteases, lipases, and the importance of bile in digestion.

Part 6 - More Help: 

Stay tuned for the next issue, where we'll explore more fascinating topics in GCSE Science.