Enzymes Flashcards
advantages of immoblised enzymes
the enzyme can be recovered and reused, which lowers costs. more than one enzyme can be used at one time. higher tolerance (more stable) to changes in temperature/pH and still have higher yields than free enzymes. product is left uncontaminated by the enzyme. can be added and removed easily.
disadvantage of immobilised enzymes
specialist enzyme equipment is required, more expensive to buy and set up
definition of immobilised enzymes
enzymes that are fixed, bound or trapped on an inert matrix
give two examples of inert matrices
cellulose microfibrils and sodium alginate beads
why do enzymes immobilised in beads have a slower reaction time than those in membrane
some of the active sites in the beads and substrate takes time to diffuse between them (enzymes on the substrate are already readily available for binding)
what do biosensors do
turn chemical signal into electrical signal
what can biosensors do
rapidly and accurately detect, identify and measure concentrations (even very low ones) of important molecules
what theory do biosensors use to work
that enzymes are specific and able to detect one type of molecule from a mixture
describe the use of biosensors in detecting blood glucose
the enzyme glucose oxidase (immobilised on a selectively permeable membrane placed in a blood sample) binds glucose = produces a small electrical current = detected by the electrode and read on a screen
