Neco 2023 Biology Question 42

Practice objective / multiple choice question 42 from the 2023 Neco Biology examination.

Neco 2023 Biology Objective / Multiple Choice Hard Difficulty
Question 42 NECO • 2023 • BIOLOGY • objective

An experiment measured the rate of an enzyme‑catalysed reaction at different temperatures: 20 °C → 2.0 mmol·min⁻¹, 30 °C → 4.5 mmol·min⁻¹, 40 °C → 7.8 mmol·min⁻¹, 50 °C → 7.0 mmol·min⁻¹, 60 °C → 3.5 mmol·min⁻¹. (a) At which temperature is the enzyme activity maximal? (b) What is the percentage decrease in activity at 60 °C relative to the optimum? (c) Briefly explain why activity falls beyond the optimum temperature.

Answer Options

A. 60 °C; 70 % decrease; thermal inactivation of the enzyme at extreme temperature
Correct Answer B. 40 °C; 55 % decrease; denaturation of the enzyme at high temperature
C. 30 °C; 45 % decrease; substrate inhibition at higher temperatures
D. 50 °C; 65 % decrease; loss of enzyme activity due to pH shift
Correct Answer
B
Correct Option:
40 °C; 55 % decrease; denaturation of the enzyme at high temperature

About This Question

This is Neco 2023 Biology Question 42. It is one of the objective questions from the 2023 Neco Biology examination.

Difficulty level: Hard .

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