An enzyme mixture in a food-processing tank is warmed from 12 °C to 22 °C. Both temperatures are below the enzymes' optimum, and the enzymes are not denatured.
Why is the reaction rate expected to rise as the mixture is warmed?
Warming changes the active-site shapes, allowing substrates to bind more easily
Collision frequency stays constant, but each collision transfers more energy to the enzyme
Warming increases the number of enzyme molecules, so more active sites are available
Warming gives the particles more kinetic energy, increasing the frequency of collisions
78 exam-style questions on Edexcel GCSE Biology 7.3 Homeostasis and thermoregulation, covering 7.3.1 Importance of a constant internal environment, 7.3.2 Importance of homeostasis, 7.3.3a Thermoregulation via the skin and hypothalamus, and 7.3.3b Vasoconstriction and vasodilation in thermoregulation. Each one has a worked solution and a mark scheme showing where the marks go.