Enzyme Immobilisation-Leaving Cert Biology

Summary

This practical demonstration focuses on enzyme immobilization using yeast cells and explores the process of converting sucrose into glucose. Yeast cells are immobilized in sodium alginate gel, and the beads are hardened using calcium chloride. The immobilized yeast is then tested for its application by converting sucrose into glucose, with results compared to free yeast. The key benefits of immobilization include enzyme stability, reusability, and producing pure products. Examples of enzyme applications in industry, such as pectinase for juice extraction and glucose isomerase for fructose production, are also discussed.

Takeaways

• 😀 Immobilized enzymes are enzymes that are fixed to each other or another material, providing stability and reusability.
• 😀 The yeast cells used in this experiment contain the enzyme sucrase, which breaks down sucrose into glucose.
• 😀 Yeast cells were immobilized by trapping them in sodium alginate gel, which was prepared by mixing the gel with distilled water.
• 😀 The yeast and sodium alginate mixture was dropped into calcium chloride solution, where it formed beads that hardened, encapsulating the yeast cells.
• 😀 After hardening, the beads were washed with distilled water to remove any free yeast cells on the outside.
• 😀 The immobilized yeast beads were tested by adding sucrose solution to a separating funnel and monitoring glucose production using glucose test strips.
• 😀 The process showed that immobilized yeast took longer to produce glucose, as sucrose must diffuse through the gel and interact with yeast cells.
• 😀 Free yeast produced glucose faster but resulted in a less pure product because the yeast was mixed with the final solution.
• 😀 Immobilizing enzymes has several advantages: it stabilizes the enzyme, allows for reuse, and produces a purer product.
• 😀 Real-world applications of immobilized enzymes include pectinase in food processing and glucose isomerase in converting glucose to fructose for the food industry.

Q & A

What is the main purpose of the enzyme immobilization practical described in the script?

The main purpose is to explore the concept of enzyme immobilization, using yeast and sucrose as examples to demonstrate how enzymes can be fixed in a gel to test their application in converting sucrose into glucose.

What is the definition of enzyme immobilization?

Enzyme immobilization refers to the process where enzymes are fixed or trapped in a material, either by bonding to each other or to a solid support, to prevent them from being removed from the system.

What method was used to immobilize the yeast cells in this practical?

The yeast cells were immobilized by trapping them in a gel made from sodium alginate, which was mixed with the yeast solution and then hardened using calcium chloride.

Why was calcium chloride used in the immobilization process?

Calcium chloride was used to harden the sodium alginate mixture, forming solid beads that trap the yeast cells inside, ensuring they remain immobilized during the process.

How were the immobilized yeast beads tested for their ability to convert sucrose into glucose?

The immobilized yeast beads were placed in a separating funnel with sucrose solution, and glucose test strips were used to monitor the production of glucose at two-minute intervals.

What was the control experiment in this practical?

The control experiment involved using free yeast cells (not immobilized) in the separating funnel with the sucrose solution, and glucose levels were tested using the same method to compare results.

Why did the immobilized yeast take longer to test positive for glucose compared to free yeast?

The immobilized yeast took longer because the sucrose needed to diffuse through the pores of the gel, interact with the yeast cells inside, and allow the glucose to diffuse out, a process that naturally takes more time.

What are the advantages of enzyme immobilization mentioned in the script?

The advantages of enzyme immobilization include stabilizing the enzyme, enabling its reuse, and producing a purer product that does not require further purification.

Can you give examples of enzymes that are used in industry, as mentioned in the script?

Examples of industrial enzymes include pectinase, used in food processing to extract juice and clarify fruit juices, and glucose isomerase, which converts glucose into fructose, a sweeter sugar.

What is the role of glucose isomerase in industry?

Glucose isomerase is used to convert glucose into fructose, which is sweeter and can reduce the need for additional sugar in products such as soft drinks.