Biology PAG 4.1 Enzyme Reaction Quiz

Questions and Answers

What is the aim of the experiment?

To investigate the effect of changing substrate concentration on the rate of hydrogen peroxide breakdown.

What enzyme breaks down hydrogen peroxide?

catalase

What hazards are present in this experiment?

Cork borer and knife are sharp; hydrogen peroxide 20 vol causes irritation.

How do you get different concentrations of hydrogen peroxide from just 20 vol hydrogen peroxide?

Serial dilutions. Signup and view all the answers

What is Step 1 of the experiment?

Serial dilution and label beakers. Signup and view all the answers

What is Step 2 of the experiment?

Cut 20 cylinders of potato using cork borer tile and knife to get to 2.5 cm each. Signup and view all the answers

What is Step 3 of the experiment?

Set up conical flask, delivery tube, measuring cylinder full of water inverted in water trough. Signup and view all the answers

What is Step 4 of the experiment?

Place four cylinders in flask and add the 2 vol hydrogen peroxide and secure bung asap. Signup and view all the answers

What is Step 5 of the experiment?

Record volume of gas given off every thirty seconds for three minutes. Signup and view all the answers

What is Step 6 of the experiment?

Dispose of contents and rinse flask and refill measuring cylinder. Repeat for other concentrations of hydrogen peroxide. Signup and view all the answers

What is Step 7 of the experiment?

Exchange data to get three values for each concentration. Signup and view all the answers

What is Step 8 of the experiment?

Calculate mean and standard deviation for at 180s and record in table. Signup and view all the answers

How do you calculate mean?

Add all values up, divide by total number of values. Signup and view all the answers

How do you calculate standard deviation?

√(sum of (mean - each value)² / number of values - 1) Signup and view all the answers

What did the results show?

As substrate concentration increases, the rate increases also until it levels off due to limitation by another factor. Signup and view all the answers

Why does the rate increase as concentration increases?

More substrates to bind to, leading to more enzyme-substrate complexes and higher product formation rate. Signup and view all the answers

Study Notes

Experiment Aim

Investigate the impact of varying substrate concentration on the rate of hydrogen peroxide breakdown.

Enzyme Involved

Catalase is the enzyme responsible for breaking down hydrogen peroxide.

Hazards to Observe

Cork borer and knife are sharp; exercise caution while using.
Hydrogen peroxide (20 vol) can cause skin irritation; wear lab coats and eye protection.

Preparing Substrate Concentrations

Use serial dilutions to create different concentrations of hydrogen peroxide.
Example process: Mix 40ml distilled water with 160ml of 20 vol hydrogen peroxide to obtain 200ml of 16 vol hydrogen peroxide.
Continue dilution by mixing 100ml of the previous solution with 100ml of distilled water.

Step-by-Step Procedure

Step 1: Conduct serial dilutions and label beakers accordingly.
Step 2: Use a cork borer, tile, and knife to cut 20 cylinders of potato, each measuring 2.5 cm, and remove the skin.
Step 3: Set up a conical flask connected to a delivery tube and an inverted measuring cylinder filled with water.
Step 4: Place four potato cylinders in the flask, add 2 vol hydrogen peroxide, and secure the bung immediately.
Step 5: Measure and record the volume of gas released every 30 seconds for 3 minutes.
Step 6: Dispose of the contents, rinse the flask, and refill the measuring cylinder. Repeat the process for other concentrations of hydrogen peroxide.
Step 7: Exchange data with peers to collect three measurements for each concentration.
Step 8: Calculate the mean and standard deviation at 180 seconds and document the values in a table.

Data Analysis

Mean Calculation: Sum all individual values and divide by the total number of values.
Standard Deviation Calculation: Use the formula √(sum of(mean - each value)² / (number of values - 1)).

Results Interpretation

Results indicate that as substrate concentration increases, the rate of reaction also increases until a limiting factor, such as enzyme concentration, is reached.
Higher substrate concentration leads to a greater number of substrates available for binding, resulting in more enzyme-substrate complexes (ESCs) and quicker product formation.

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Description

This quiz focuses on PAG 4.1 in biology, which examines the effect of substrate concentration on the rate of enzyme-controlled reactions. It covers key concepts such as the enzyme involved, hazards, and experimental aims related to hydrogen peroxide breakdown. Test your knowledge on catalase and safety precautions in laboratory settings.