Enzyme Activity at Optimum pH — NEET Biology
✅ Asked in NEET 2024Enzymes generally function in a narrow range of temperature and pH. Each enzyme shows its highest activity at a particular temperature and pH called the optimum temperature and optimum pH. Activity declines both below and above the optimum value. Low temperature preserves the enzyme in a temporarily inactive state whereas high temperature destroys enzymatic activity because proteins are denatured by heat.
NTA tests whether students understand that enzymes have a specific optimum pH where they show maximum activity, and that activity decreases on either side of this value. A common mistake is confusing optimum pH across different enzymes—pepsin works best at acidic pH (~2), while trypsin prefers alkaline pH (~8). Students often assume all enzymes have the same optimum pH. Remember: changes in pH denature the enzyme or alter its active site charge, reducing substrate binding. When a NEET question shows an enzyme activity graph, identify the peak as optimum pH, not just any point where activity exists.
This paragraph was tested 2 times in NEET.
Which of the following graphs correctly represents the effect of pH on enzyme activity?
Given below are two statements:Statement I: Low temperature preserves the enzyme in a temporarily inactive state whereas high temperature destroys enzymatic activity because proteins are denatured by heat. Statement II: When the inhibitor closely resembles the substrate in its molecular structure and inhibits the activity of enzyme, it is known as competitive inhibitor.
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