Enzymes Practical

Question 1

what is the rate of an enzyme controlled reaction influenced by?

Answer 1

-temperature
-pH
-conc of substrate
-conc of enzyme

Question 2

brief description of method of this practical?

Answer 2

-milk solution heated in test tubes with X on them
-add buffer and enzyme and mix
-put back in water bath
-time how long it takes for colour change and X to not be visible

Question 3

why use buffer solution?

Answer 3

maintain constant pH

Question 4

why leave test tubes in the water bath before you add enzyme?

Answer 4

all reach correct temp

Question 5

why use a water bath at room temp?

Answer 5

temp variation greater in air than water so water bath keeps test tubes at constant temp

Question 6

why three experiments at each temp?

Answer 6

allow calculations of a more reliable mean as anomalous data can be identified

Question 7

how do we make sure temp in water bath is as reliable as possible?

Answer 7

as a minimum, measure temperature at beginning and end of experiment to assess any changes. But ideally measure at regular intervals with a thermometer and buffer any changes.

Question 8

why can’t optimum temperature be concluded?

Answer 8

not every temp was measured

Question 9

what is wrong about determining when X disappeared?

Answer 9

subjective

Question 10

what is a better way of determining colour change?

Answer 10

colorimeter to record time taken to reach constant value of absorbance