Question

1. Maltose is a disaccharide of glucose. Why is maltose not used to illustrate the specificity of salivary amylase in the practical laboratory activity?

Select one:

a. Because salivary amylase breaks down the bond between the two glucose molecules.

b. Because maltose is too small

c. Because maltose is similar to starch

d. Because maltose is a reducing sugar

2. Why is salivary amylase not able to break down starch when incubated with the HCl solution?

Select one:

a. Because the enzyme was at its optimal pH for digestion of starch

b. Because the enzyme was denatured

c. Because the solution was buffered

d. Because of the enzyme specificity of amylase

3. When the raw starch is incubated at pH 7 in presence of salivary amylase results being positive for both Iodine test and DNS tests indicates that

Select one:

a. The test are only working at pH 9

b. Only cooked starch can be digested by salivary amylase

c. No reducing sugars have been released from the starch molecule

d. The raw starch is only partially digested

Answer 1

Answer-1 Option(b) because maltose is too small . Salivary amylase can only act on the middle glycosidic bond not on glycosidic bond present at the end of the chain . Maltose being a disaccharide , has only one glycosidic bond which is considered as end glycosidic bond by the enzyme. Answer-2 Option( b) the pH of atomach is very acidic hence the enzyme gets denatured and not able to perform its activity. Answer-3 Option( d) Raw sugar is partially digested. Because the digested sugar is giving positive DNS test and undigested sugar is giving positive starch test