Part 8: The Role Of Stomach Acid And Bile

Question 1

Explain the activity of pepsin.

Answer 1

Pepsin thrives in acidic conditions, so it digests meat quicker when with hydrochloric acid than when it (pepsin) is alone.

Question 2

Suggest how scientists ensured the results of this experiment were valid.

Answer 2

The scientists repeated the experiments multiple times.

Question 3

Describe the role of the three tissues found in the stomach: muscular, glandular, and epithelial.

Answer 3

Muscular: contracts to churn food and push food through the digestive tract.
Glandular: produces enzymes and hydrochloric acid.
Epithelial: covers inside and outside of the stomach and mucus to protect the lining from the acid.

Question 4

Name three roles of hydrochloric acid.

Answer 4

Kills bacteria
Provide correct pH for protease to work
Aid in chemical digestion by making it easier to break chemical bonds

Question 5

Describe what happens when oil and vinegar are mixed together.

Answer 5

Small droplets are formed because the oil separates the vinegar into small droplets.

Question 6

What does this tell us about the importance of bile?

Answer 6

This provides a larger surface area for the lipase enzymes to digest the fat droplets, therefore speeding up the digestion of fats.