At low temperature, the rate of enzyme reaction is low as the temperature increases, the rate of enzyme increases. This is because at high temperature, the enzyme and substrate molecules move faster, increasing the rate of collision and reaction occur more frequently. At low temperature(below 40'C), a rise of 10'C will double the rate of reaction. The optimum temperature for an enzyme is 37'C. At high temperature( above 40), enzymes become denatured rapidly due to changes in shape of the enzyme molecules. The substrate molecule cannot attach itself to the newly-shaped active site of the enzyme molecule once denatured Enzymes are denatured by changes in the pH level of the reaction medium.Enzymes work best at optimum pH of 7.Enzymes will be inactive when it reaction medium becomes too acidic or alkaline. A change in pH results in a change in the concentration of hydroxyl ions and hydrogen ions. The excess hydrogen ions or hydroxyl ions destabilise the enzyme by changing the shape of the active site and the enzyme.
at low temp: enzymes are inactive as temp increases: enzymes become more active and reach optimum temp where the enzyme activity is at its peak beyond optimum temp: the enzyme starts to denature and so enzyme activity decreases enzyme works at one optimum ph and below or beyond optimum ph, enzymes denature