Lab3: Enzymatic activity Pre lab questions: 1) What is the reaction catalyzed by

Question

Lab3: Enzymatic activity

Pre lab questions:

1) What is the reaction catalyzed by the enzyme that we are testing in this lab?

2) How are we measuring the activity of the enzyme in this lab?

3) Considering the data that you will acquire, what units would you use to express the rate of cellobiase activity?

4) What characteristic of the stop solution is necessary to make the reaction visible?

5) What type of mushroom do you expect to have the highest cellobiase activity and why? (hint: think about the environment where they grow).

Enzymatic reactions: how to make biofuel

GOALS

- illustrate the concept of enzymatic reactions

- illustrate the concept of enzymatic kinetics

- quantify enzymatic activity from natural sources

- introduce the concept of industrial use of biological reactions in biofuel production.

INTRODUCTION

In this lab we are going to measure rates of enzymatic reactions. Enzymes are catalysts that speed up chemical reactions transforming substrates into products. The enzyme that we will investigate is cellobiase, which transforms cellobiose into glucose. This step is a critical reaction in the production of glucose from vegetal material during the production of ethanol in the biofuel industry.

Your lab experiment will take advantage of a colorimetric analysis of the production of glucose by the enzyme -glucosidase, which acts as a cellobiase. This will allow you to:

1) Determine the rate of the enzymatic reaction.

2) Compare the rates of reaction in function of the amount of enzyme.

3) Determine the rate of reaction from a natural extract and therefore quantify the amount of enzyme in that extract.

The lab is organized in three parts:

Part A: Establish a standard curve of product (p-nitrophenol) for quantitation of enzymatic activity.

Part B: Determine the rate of enzymatic activity for different amounts of enzymes

Part C: Determine the rate of cellobiase activity and the amount of enzyme in fungi.

Explanation / Answer

1. The enzyme we are studying in the lab is cellobiase. The reaction it catalyzes is the reaction where it transforms cellobiose into glucose. This step is crucial for the production of ethanol in biofuel industry.

2. Usually enzyme assays are used to identify the activity of enzyme in lab but here we employ colorimetric analysis.

3. The unit that can be given for measuring activity can be U or micromol/min.

4. The main problem with cellobiose and glucose is that they are colourless annd difficult to quantify. So if use a basic solution as a stop solution we can develop the colour of p-nitrophenol to yeelow and can stop the reaction.

5. Shiitake mushrooms are the best source of cellobiase and have high p-nitrophenol.

Related Questions

Navigate

• Browse (All)
• Browse L
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.