Question

Radioisotopes are frequently used in the study of cells. Assume a culture of E. coli is grown in a culture medium containing radioactive sulphur. At the end of 48 hours, it is expected to find the radioactive label located in
A.DNA
B. enzymes
C. RNA
D. all of these

Answer 1

Hola mate !! ✌️✌️

here's your answer...⬇️⬇️

Sulphur is a constituent of proteins. Enzymes are proteinaceous in nature .

So radioactive sulphur will be found in enzymes .

Correct option is ...$\boxed {B. enzymes.}$

hope it helps !! ❤️❤️

Answer 2

The radioactive label in a culture of E. coli is found in (B) Enzymes.

• A material takes up the radioactive element only if it has the element in it. Sulphur is an element present in proteins. Since enzymes are proteinaceous substances, they contain sulphur in them due to which they receive the radioactive sulphur label in them. Usually, Sulphur - 35 is added to radioactively label the protein or enzyme material.
• DNA contains a phosphorous element in it so it can be radioactively labeled when radioactive phosphor is added to it.
• Similarly, RNA and DNA have similar structures with few differences. Both have phosphorous elements in them. Even RNA can be radioactively labeled with the help of Radioactive phosphorous.  Usually, Phosphor - 32 is added to radioactively label the DNA or RNA material.
• Therefore enzymes or proteins have a radioactive label in them due to the addition of radioactive sulphur.

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