Enzyme subrate reaction

 

 

Lab Report

                                                                                  Biology 101

Prof. Woo

October 02, 2013

 

Reaction time vs. quantity of Substrate

 

By Wilnor Jean

 

 

 

Lab Partners:

Enun Samson

Alejandra Vazquez

Cindy Alvarez

Jonathan OJeesh

 

Introduction

A substrate is a substance that is acted upon by an enzyme and Enzymes are proteins that act as catalysts for biological reactions. In this experiment we will measure the amount of time it takes for the solution to change color if more substrates are used. The question we need to get answer is:  Does the reaction go slower when the amounts of substrates are increased? And our Hypothesis is:  If more substrates are present then the reaction will go slower.                  

Experiment design:

Material used:

   -  5 test tubes,

- A beaker with substrates

-A beaker of 30 ml of water

-A beaker of 30 ml of   enzymes.

 Create of enzymes: We used potato to extract the enzymes.7

1. 75 g of peeled and cubed potato 250 ml water into a blender

2. Blend at high speed for 1-2 minutes

3. Strain the mixture using a funnel and double layer of cheesecloth.

4. put about 30 ml of the potato juice into each of the 50 ml beakers of the classroom groups

Experiment in action:

-          We label four of these tubes 1 through 4; the remaining tube was used; it served as a control.

-            We   added substrates: 30 drops of substrates in tube number one, 20 drops in tube number two, 10 drops in tube number three, 5 drops in tube number four, and the remaining tube (5) ten ; And then half full( approximate 2 cm) with water.

-          The test tubes have been added with 10 drops of enzymes to each and at approximately the same time we shake them and record the amount of time that each of them takes for the solution to change color.

-          The control test tube (# 5) doesn’t have the potato extract enzyme.

Result:

 Test tube # 5, negative to change in color

    Solution in Test tube # 4 changes to yellow color at approximately 2 minutes.

Solution in tube # 3 reaches the same color as tube 4 at approximately 3 minutes.

Solutions in tube 2 were changed slightly yellow   at approximately 4 minutes.

Solutions in tube 1 were changed slightly yellow   at approximately 6 minutes

The solution in tube number 4 has less substrate, and it takes approximately 2 minutes to react.

The control test tube stayed colorless

Table 1.  Represent the test tubes with the amount of solution and the reactions’ time

Test tubes	Enzymes ( drops)	Substrates ( drops)	water	Result ( recorded time in minutes)
1	10	30	2 cm	6
2	10	20	2 cm	4
3	10	10	2 cm	3
4	10	5	2 cm	2
5	10	0	2 cm	No change

 

Graph1. The Y-as represent the approximately time the solution change color compare to the normal concentration of substrates. The x-as represent the amount drops of substrates in each test tube.

As shown by our graph and table, we can conclude that the higher the concentration of the substrate, the higher the reaction time.

 

 

 

Conclusion

The object of this experiment is to measure the amount of time it takes for the solution to change color if more substrates are used. The result does support my hypothesis. It’s showed that when more substrate is present and the amount enzyme stay the same the reaction goes slower. Even though we could not repeat the experiment to double check it, it showed that how more substrate we added, how longer it took to change color. There was no change in the control tube which means that there was no reaction between the enzyme and water. The most challenges we encounter was the time, we were in such hurry we did not have enough time to truly measure the tubes one by one. I believe if I would have to do this experiment against I would spent more time to double check each tube for accuracy. The other issue was the observation between tube 4 (less substrate) and the rest; the color change was lighter because there was less substrate to turn the color in fully yellow. But it was the first test tube which in the solution change color. I hardly could figure out if there were changes between tube one and two, they were slightly yellow and they stayed for like that. There was no big difference in the reaction times maybe next time we should use greater range concentration (50, 60...).As shown by our graph and table, we can conclude that the higher the concentration of the substrate, the higher the reaction time.

References

Laboratory Investigations Third Edition by; Clark M.B and Riddle M.R.

Wikitionary