Biomolecules+Enzyme+Action+pH

Aim: To investigate the effect of pH on enzyme action.

Hypothesis: When the pH is slightly acidic or neutral the enzyme would work well. This is because the enzymes that we have in our bodies are acids (e.g. Hydrochloric acid in our stomach).

Results:
 * Part A ||
 * Test Tube |||| Colour of Iodine solution ||
 * || 0 mins || After 10 minutes ||
 * W || Blue black || Brown ||
 * X || Blue black || Brown ||
 * Y || Blue black || Brown ||
 * Z || Blue black || Blue black ||

Interpreting the results (Data Analysis): Tube W, X and Y had shown that starch digestion has occurred. All tubes had the same amount of starch and all tubes except for Z had the same amount of amylase. Hydrochloric acid was added to W, distilled water was added to X and ammonium hydroxide was added to Y. Z was the control with no amylase and just distilled water. Iodine turns blue-black when in contact with starch so the tubes that remained brown were the ones that went through starch digestion. Tubes W, X and Y remained brown when tested with iodine, meaning that starch digestion had taken place. Tube Z became blue black meaning that no starch digestion took place.

Conclusion: This means that acidic (hydrochloric acid), alkali (ammonium hydroxide) and neutral (distilled water) conditions are suitable for enzyme activity.