Biological catalysts are protein molecules which 1. speed up a chemi

Biological catalysts are protein molecules which

  • 1. speed up a chemical reaction
  • 2. remain unchanged after reaction
  • 3. function optimally at 37 °C
  • 4. do not have an enzymatic activity

Select the correct answer using the code given below.

1 only
1, 2 and 3
2 and 3 only
1, 3 and 4
This question was previously asked in
UPSC CDS-2 – 2016
Biological catalysts (enzymes) are protein molecules that speed up chemical reactions, remain unchanged after the reaction, and function optimally at around 37 °C (in the human body).
– Biological catalysts are enzymes, which are indeed protein molecules (with a few exceptions like catalytic RNA).
– Statement 1 is correct: Enzymes are catalysts, meaning they increase the rate of a chemical reaction without being consumed in the process.
– Statement 2 is correct: Like all catalysts, enzymes are not permanently altered or used up during the reaction and can be reused.
– Statement 3 is generally correct in the context of human enzymes: Many enzymes in the human body function optimally at physiological temperature, which is around 37 °C. However, the optimal temperature varies greatly among enzymes from different organisms (e.g., enzymes from thermophilic bacteria function at much higher temperatures). Assuming the question refers to typical biological contexts like the human body, this statement is considered correct.
– Statement 4 is incorrect: Biological catalysts *are* enzymes, and their activity *is* enzymatic activity. This statement directly contradicts the definition.
– Based on the statements, 1 and 2 are universally true for catalysts. Statement 3 is true for a common subset of biological catalysts (human enzymes). Statement 4 is false. The option including 1, 2, and 3 is the most fitting choice.
Enzymes are highly specific for the substrates they act upon and the reactions they catalyze. Their activity is influenced by factors such as temperature, pH, and the presence of inhibitors or activators.