Investigations into the effects of different factors on enzyme activity

How to measure how fast the effect of temperature on the rate of reaction appears equipment?

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What enzyme are you using for this reaction to measure the effect of temperature rate of an enzyme controlled reaction?

Catalase

What does catalase catalyse?

the breakdown of hydrogen peroxide into water and oxygen

IV?

temperature

DV?

volume of oxygen produced

Variables to control?

pH, enzyme concentration and substrate concentration

What do you set up the boiling tubes to contain?

same volume and conc of hydrogen peroxide

What do you do to keep the pH constant?

add equal volumes of buffer solution to each tube

What do you set up to measure the amount of oxygen produced?

delivery tube and upside down measuring cylinder

How do you heat the solution?

put in water bath (40', 30', 20' and 10')

What do you use a pipette to add the same volume and concentration of to each boiling tube?

catalyse

What do you record?

how much oxygen is produced in the first 60 seconds - stopwatch

What do you repeat the experiment at?

each temperature 3 times

What do you use the results to find?

mean volume of oxygen produced at each temperature

How to calculate the mean rate of reaction at each temp?

divide vol of oxygen produced by time taken

What would you do to reaction if you want to investigate the affect of pH?

add a buffer solution with a different pH to each tube (keep temp the same)

What would you do to reaction if you want to investigate the affect of substrate concentration?

boiling tubes with different concentrations of hydrogen peroxide (temp the same)

How else to measure the rate of an enzyme controlled reaction?

the disappearance of the substrate (rather than the appearance of product)

Diagram of apparatus for measuring the disappearance of the substrate?

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Example?

regularly sample the breakdown of starch to maltose by amylase (alter conditions)