1. What term is given to enzymes physically confined or localized in a certain defined region of space with retention of their catalytic activities, and which can be used repeatedly and continuous?
- 1) Catalysed enzymes
- 2) Immobilized enzymes
- 3) Localisation of enzymes
- 4) Localized enzymes
Answer: 2)
Explanation: The entrapment of enzyme solution within a confined space for the purpose of retaining and re-using enzyme and using the enzyme for a longer time in processing equipment. It can be done through using polymers to confine the drug.
2. Who reported the first industrial use of immobilized enzymes in 1967?
- 1) Kary Mullis
- 2) James Watson
- 3) Chibata and co-workers
- 4) Robert Hook
Answer: 3)
Explanation: They have also developed the immobilization of Aspergillus oryzae aminoacylase for the resolution of synthetic racemic D-L amino acids. In their work fungal aminoacylase was immobilised on DEAE-Sephadex through ionic bonding. They used this system to produce l-aspartate from ammonium fumarate.
3. The most common procedures of irreversible enzyme immobilization are covalent coupling, entrapment or micro-encapsulation and _______
- 1) Cross-linking
- 2) Covalent bonding
- 3) Di-sulphide bonding
- 4) Hydrophilic linkage
Answer: 1)
Explanation: The concept of irreversible immobilization means that once the biocatalyst is attached to the support it cannot be detached without destroying either the biological activity of the enzyme or the support. Thus the most common procedures of irreversible enzyme immobilization are covalent coupling, entrapment or micro-encapsulation and crosslinking of the enzyme with polymers.
4. What is the method name that is based on the occlusion of an enzyme within a polymeric network that allows the substrate and products to pass through but retains the enzyme?
- 1) Hollow fibre
- 2) Microencapsulation
- 3) Covalent coupling
- 4) The entrapment method
Answer: 4)
Explanation: In this method, the enzyme is not bound to the matrix or membrane. There are different approaches to entrapping enzymes such as gel or fibre entrapping and micro-encapsulation.
5. In physical adsorption the enzymes are attached to the matrix through hydrogen bonding, van der Waals forces, or hydrophobic interactions; whereas in ionic bonding, the enzymes are bound through?
- 1) Cross-linking
- 2) Salt linkages
- 3) Di-sulphide bonding
- 4) Hydrophilic linkage
Answer: 2)
Explanation: The simplest immobilization method is nonspecific adsorption, based on physical adsorption or ionic bonding for the drug molecules with the polymeric molecules. The bonding between the drug and the polymer compound is reversible. It also influences the strength of the interaction.
6. Which of the physical property of the matrices particularly determine the surface area and binding capacity?
- 1) Pore parameters
- 2) Compression behaviour
- 3) Mechanical strength
- 4) Swelling behaviour
Answer: 1)
Explanation: Physical characteristics of the matrices such as mean particle diameter, swelling behaviour, mechanical strength and compression behaviour, etc. These physical characteristics are important for the performance of the immobilized conditions. Pore parameters and particle size determine the total surface area.
7. Which of the following are natural mineral polymers?
- 1) Silica
- 2) Agar
- 3) Dextran
- 4) Cellulose
Answer: 1)
Explanation: Natural polymers are which will be polysaccharides are cellulose, dextran. Agar, agarose, chitin, alginate. Natural polymers of protein categories are collage, albumin. Inorganic natural polymers are bentonite and silica. Inorganic processes materials are glass, metals, etc.
8. What is the name of method used to attach enzymes to stationary solids by weak physical forces?
- 1) Capillary action
- 2) Adsorption
- 3) Cross linking
- 4) Absorption
Answer: 2)
Explanation: Attachment of enzymes to stationary solids by weak physical forces such as Vander waals forces or dispersion forces. Active site is normally unaffected and nearly full activity is observed. Desorption of enzymes is a common problem.
