The aim of the Assessment Task 1 is to investigate the effect of 1)
on the action of enzyme such as catalase on hydrogen peroxide. Background knowledge:
Enzymes are organic catalysts composed of proteins that assist organisms in facilitating metabolic reactions without undergoing any change themselves. Enzymes are sensitive to their environment and so must remain within a stable range of factors ( pH, temperature , substrate concentration etc) for them to function. Any deviations from this stable state can result in decreased efficiency or even the denaturing (destruction) of the enzyme. What affects enzymes:
Temperature- Enzymes stop working if the temperature rises above 40ºC. Increasing the temperature alters the 3D shape and so the enzyme can no longer fit the substrate. 2)
pH- They work best in neutral conditions neither acidic nor alkaline. 3)
Substrate concentration – Increasing the substrate concentration, increases the activiy of the enzymes till it reaches an optimal point beyond which there is no change in the enzyme acitivity. Catalase Enzyme:
The activity of an enzyme can be demonstrated using liver, which contains the enzyme, catalase. Hydrogen peroxide breaks down slowly to form water and oxygen. One molecule of Catalase can deal with six million molecules of Hydrogen Peroxide in 1 minute. This breakdown happens rapidly in the present of the Catalase and Oxygen gas evolves rapidly and can be tested with a glowing splint or rising bubbles (variable). Changes in the temperature, acidity (pH) and concentration of the hydrogen peroxide will affect the rate of the reaction. The control was to have a test tube of just substrate without any enzymes present. The validity would be to test each variable in isolation without mixing any of the 3 variables namely, the pH, temp and substrate concentration. The amount of catalase and hydrogen peroxide will remain the same in all the test...
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