2.13: Understand How Enzyme Function can be Affected by Changes in pH altering the Active Site

ENZYMES: Protein molecule that acts as a biological catalyst by speeding up the rate of specific reaction without being used up or affected
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• Enzymes are biological catalyst in metabolic reactions (digestion) as they allow substrates to bind onto their active site, breaking them down into products

EFFECT OF pH ON ENZYME ACTIVITY

Diagram showing the Effect of pH on Enzyme Activity

EXPLANATION: As the pH increases towards optimum, the rate of enzyme activity increases This is because as pH increases, the shape and structure of the active site, and the charge of substrate molecule will both be optimal to allow the substrate to bind to the active site of enzyme This allows more frequent successful enzyme-substrate collisions to occur, increasing the rate in which substrates are broken down, hence increasing enzyme activity However, as pH exceeds optimum, enzymes will denature This is because the increase/decrease from optimum pH causes the shape and structure of active site to change, additionally changing the charge fo substrates, therefore diminishing the ability of substrate to bind to active site of enzymes Therefore, enzymes denature and metabolic reactions cannot take place