Lesson 2 Flashcards
(10 cards)
Name factors affecting enzyme action
pH, temperature, substrate and enzyme concentration, inhibitors
How do high temperatures affect enzymes?
Temps above optimum increases vibrations which can break hydrogen bonds and very high temperatures can completely denature enzymes
Why do extreme pHs decrease enzyme action?
Electrostatic charge of chains of amino acids could be altered and repel substrate if they have same change and can denature enzyme
How do competitive inhibitors decrease enzyme action?
• Similar shape to substrate
• So can be complementary to enzyme and prevents actual substrate from binding
• Less substrate complexes formed
Describe the difference between competitive and non-competitive inhibitors
Non comp-inhibitors bind to allosteric site which changes shape of normal active site meaning no substrate complexes can be formed
What is an immobilised enzyme?
Enzyme which is fixed, trapped or bound to an inert matric
Name ways in which an enzyme can be immobilised
Adsorption onto matrix, covalent bonding to a support, trapping within a fibrous matrix, encapsulation behind a selectively permeable membrane
Why are immobilised enzymes on membrane good?
Beads on a surface are more accessible whereas enzymes in beads need time to diffuse
Describe advantages of immobilised enzymes
• Easily removed for reuse and to control reaction rate
• Product not contaminated
• Increased stability over wider range of temps and pH
Describe uses of immobilised enzymes and fuse
• Lactose free milk - Immobilised lactase hydrolyses lactose
• Biosensors - Rapidly detect low conc. of certain substance in complex mixture such as blood