Recall the basic properties of enzymes

Enzymes are biological catalysts, usually proteins, that:

• are highly specific in their action,
• possess a well-defined active site where the substrate binds,
• function best under mild conditions of temperature and pH,
• can be poisoned/inhibited by certain chemicals,
• are generally considered homogeneous catalysts in the biological medium, not heterogeneous catalysts.

Evaluate each option

Option A

"Enzymes are specific biological catalysts that can normally function at very high temperature $(T \sim 1000\,K)$"

This is incorrect. Enzymes are proteinaceous in nature and usually get denatured at high temperatures. They do not function at extremely high temperatures like $1000\,K$.

Option B

"Enzymes are specific biological catalysts that possess well-defined active sites"

This is correct. The active site is the specific region of the enzyme where the substrate binds and the reaction occurs.

Option C

"Enzymes are specific biological catalysts that can not be poisoned"

This is incorrect. Enzymes can be poisoned or inhibited by substances such as heavy metal ions, cyanide, etc.

Option D

"Enzymes are normally heterogeneous catalysts that are very specific in their action"

This is incorrect. Although enzymes are very specific, they are not normally heterogeneous catalysts. In biological systems they generally act in solution, so they are treated as homogeneous catalysts.

Conclusion

The only correct statement is: $\boxed{\text{B}}$

Comparison with stored correct answer

Stored correct answer: B

My derived answer: B

Hence, the derived answer agrees with the stored correct answer.