Assignment

Question 1

Title

Answer 1

Enzyme activity

Question 2

Aim

Answer 2

To investigate what effect increasing substrate concentration has on enzyme activity

Question 3

Underlying biology

Answer 3

Metabolic pathways are enzyme catalysed reactions that occur within a cell. They are integrated and controlled.

In metabolic pathways, reactions can be described as anabolic and catabolic.
An anabolic reaction is the build up of smaller molecules to produce a larger molecule. This reaction requires energy. A catabolic reaction is the break down of larger molecules to produce smaller molecules. This reaction releases energy.

Metabolic pathways can be controlled by the absence or presence of a particular enzyme and by the rate of this enzyme’s reaction rate.

An enzyme has an active site which is specific to a substrate molecule. This substrate molecule has a high affinity for its active site therefore it is attracted to it. Induced fit is a process which occurs after the substrate binds, this is where the active site changes to fit the substrate molecule better.

Enzyme activity can be increased by increasing its substrates concentration, until the enzyme reaches its threshold - when all available active sites are already reacting with substrate molecules.

Question 4

Brief description

Answer 4

To carry out our experiment we added the hydrogen peroxide concentration into our boiling tubes and then added our catalase - ensuring to measure each volume with a measuring cylinder.

We then set a timer and allowed the reaction to occur for one minute. After the allocated time we measured the height of foam produced using a ruler.

We completed the experiment again for each hydrogen peroxide concentration. We repeated the experiment at each concentration three times.

Question 5

Analysis

Answer 5

In my experiment, I had a range of hydrogen peroxide concentrations from 0%- 15%, the average height of foam produced for these concentrations increased from 0mm at 0% to 11mm at 15%. The increase in height of foam produced indicates an increase in enzyme activity.

The data collected from the internet source had a similar set of results however their hydrogen peroxide concentrations were measured in mm and ranges from 0mm to 10mm.

Their height of foam produced also increased as the hydrogen peroxide concentration increased from 0mm - 9.5mm. The increase in height of foam in this experiment means that the enzyme activity increased as hydrogen peroxide increased

Question 6

Analysis 2

Answer 6

My results show that as the hydrogen peroxide concentration increase from 0% to 15 %, the average height of foam produced for these concentrations increased by 1100%

11/0 x 100 = 1100

This means that enzyme activity is increased as the substrate concentration increases

Question 7

Conclusion

Answer 7

In conclusion, an increase in substrate concentration will cause enzyme activity to increase, as shown by the height of foam produced - presented in graph one

Question 8

Evaluation

Answer 8

In order to increase the validity of my results i could of ensured the temperature remained the same at each concentration- as temperature can also affect enzyme activity. I could of done this by completing my experiment in a water bath to ensure the temp was the same each time.

I could of also increased the accuracy of my results by using a pipette rather than a measuring cylinder. A pipette would of measured the volumes of liquid more precisely.

My internet source’s resukys were reliable as they repeated the experiment at each concentration. I know this because in their graph the clearly state that their data is an average.