Question

The marker enzyme of lysosome is-
A) Lysozyme (muramidase)
B) Beta galactosidase
C) Acid phosphatase
D) None of the above

Answer 1

Hint:Lysosomes contain hydrolases enzymes which have digestive properties. Acid phosphatase has a digestive function and is present in lysosomes.

Complete answer:
Lysosomes are cell organelles present as vesicles. They are surrounded by a single membrane and contain hydrolysing enzymes. They are produced by Golgi apparatus and encircle around 60 types of acid hydrolases like nucleases, proteases, lipases, phosphatases, etc. which are used for digestion of various materials. Enzymes that are not ubiquitous but confined to a specific type of organelle or a subcomponent of a cell is called Marker enzymes. They are used for isolation of the target cellular component as their presence confirms the presence of the target. Succinate dehydrogenase is a marker enzyme for mitochondria whereas the acid phosphatase, a component of lysosome and is considered as a marker enzyme of lysosomes along with glucuronidase and N-acetyl-d-hexosaminidase, etc. Acid phosphatase, present as acid glycerophosphate, phosphomonoesterase, phosphomonoesterase, acid monophosphatase, acid phosphohydrolase, acid phosphomonoester hydrolase, acid nucleoside diphosphate phosphatase, orthophosphoric-monoester phosphohydrolase, is a type of enzyme which releases the free attached phosphoryl groups from molecules during digestion. Example- phosphomonoesterase, an acid phosphatase, fuse with endosomes and acidifies it to maintain an acid pH optimum. It is present in many animal as well as plant species.
Acid phosphatase in general, catalyzes the following reaction at an optimal acidic pH (below 7):
$Orthophosphoric Monoester + {H_2}O \to Alcohol + {H_3}P{O_4}$

Thus, the correct answer is option C. Acid phosphatase.

Note:Use of phosphatase enzymes by soil microorganisms is observed in order to access organically bound phosphate nutrients. Rates of activity assay of acid phosphatases can be used for ascertaining biological demand for phosphates in the soil.