Page 112 - Biology - XII

Conclusion
The starch in saucer C gets converted into sugar by the enzyme—amylase, which was extracted from the
pea cotyledons.
Starch is digested by enzyme amylase.

Precautions
1. Take enough quantity of germinating seeds for extraction of enzyme.
2. Add less quantity of iodine solution.

VIVA VOCE

Q1. What are enzymes?
Ans. Enzymes are biocatalysts that regulate the biochemical reactions in the living beings or outside
the living beings.
Q2. Why did you use germinating seeds instead of dry seeds?
Ans. Because the germinating seeds have active enzymes.

Q3. Which enzyme you extracted/which enzyme was present in the cotyledon extract?
Ans. Amylase
Q4. Name the substrate on which this enzyme acts and what is the end product?
Ans. Substrate is starch and the end product is sugar—maltose.

Q5. What is the role of iodine solution?
Ans. Iodine solution is used as an external indicator to detect the presence of starch in the medium.

COMPETENCY BASED QUESTIONS

Multiple Choice Questions

Q1. Cyanide acts as an enzyme inhibitor even at very small quantities, such as
(a) 1 m (b) 0.01 m (c) 0.001 m (d) 0.0001 m

Q2. Which one of these is not a proteolytic enzyme?
(a) Cellulase (b) Maltase (c) Myrosinase (d) All of these

Q3. Zymase the fi rst known of all the enzymes is
(a) oxidoreductase (b) ligase (c) both (a) and (b) (d) none of these
Q4. Amylase is an example of

(a) hydrolase (b) carbohydrase (c) lyases (d) both (a) and (b)
Q5. Enzymes have high molecular weights. Urease enzyme has the molecular weight of
(a) 10,000 (b) 20,000 (c) 4,000,000 (d) 10,000,000

Answer key

1. (d), 2. (d), 3. (a), 4. (d), 5. (c)

111