(a) State the role played by the following in the process of digestion.
(i) Enzyme trypsin
(ii) Enzyme lipase
(b) List two functions of finger like projections present in the small intestine.
(a) State the role played by the following in the process of digestion.
(i) Enzyme trypsin
(ii) Enzyme lipase
(b) List two functions of finger like projections present in the small intestine.
Official answer
(a) Role of digestive enzymes:
(i) Enzyme Trypsin: It is secreted by the pancreas (as part of pancreatic juice) into the small intestine, where it digests proteins into simpler peptides/amino acids.
(ii) Enzyme Lipase: It is also secreted by the pancreas and is responsible for breaking down emulsified fats into fatty acids and glycerol.
(b) Two functions of finger-like projections (villi) present in the small intestine:
- Increase Surface Area: They vastly increase the inner surface area of the small intestine to maximize the absorption of digested food.
- Transport of Nutrients: They are richly supplied with blood vessels that carry the absorbed food to each and every cell of the body for energy, tissue building, and repair.
Marking scheme
- 1.State the role of trypsin (digests proteins) (1 mark)
- 2.State the role of lipase (breaks down emulsified fats) (1 mark)
- 3.List two functions of villi (increasing surface area for absorption and rich blood supply to transport nutrients) (1 mark)
Hint
Think about the pancreatic enzymes that act in the small intestine on proteins and fats, and how the structure of the small intestine is modified to absorb the digested nutrients.
Quick oral answer
Trypsin digests proteins, while lipase breaks down emulsified fats. Villi increase the surface area for absorption of digested food and transport it to the blood vessels.
Common mistakes
- 1.Confusing trypsin with pepsin (pepsin acts in the acidic medium of the stomach, whereas trypsin acts in the alkaline medium of the small intestine).
- 2.Forgetting to mention that lipase acts specifically on 'emulsified' fats rather than large fat globules.
Analysis and explanation
According to the NCERT text, digestion of complex food molecules is facilitated by biological catalysts called enzymes. In the small intestine, pancreatic juice containing trypsin and lipase acts on proteins and emulsified fats respectively. Once digested, the food is absorbed by the inner lining of the small intestine. This lining is adapted with finger-like folds called villi to increase the surface area for absorption and directly transfer nutrients into the bloodstream.
Interesting facts
The surface area of the human small intestine, thanks to the extensive folding of the villi and microvilli, is roughly equivalent to the size of a standard tennis court!
Question details
Q19 of 30 questions
- Board
- CBSE
- Class
- Class 10
- Subject
- Science
- Year
- 2020
- Section
- Section B
- Marks
- 3
- Type
- Short Answer
- Chapter
- Life Processes
- Topic
- Nutrition in Human Beings
- Bloom's level
- Remembering
- Syllabus topic
- Alimentary canal; digestive glands and enzymes; absorption in the small intestine.
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Frequently asked questions
How many marks does this question carry in CBSE Class 10 Science 2020?
This question carries 3 marks in the CBSE Class 10 Science 2020 examination.
Which chapter does this question come from in Science?
This question is from the chapter "Life Processes" in the CBSE Class 10 Science syllabus.
What topic does this question cover in Science?
This question covers the topic "Nutrition in Human Beings" from CBSE Class 10 Science.
What type of question is this in the CBSE Class 10 Science 2020 paper?
This is a Short Answer question from Section B in the CBSE Class 10 Science 2020 paper.