enzymes- Flashcards
what are enzymes
-globular proteins
-soluble-hydrophilic r groups
-biological catalysts
-specific
-tertiary structure contains an active site.
what is metabolism
a combination of all anabolic and catabolic reactions in the body controlled by enzymes.
what is the metabolic pathway
a sequence of enzyme controlled reactions in which a product of one reaction is the reactant in the next.
what is the lock and key hypothesis
substrate molecules complementary to active site
what is the induced fit hypothesis
shape of active site is not fully complementary to substrate. As a substrate binds the active site changes shape weakening bonds in the substrate which makes it easier to break down.
what is intracellular enzyme action
inside cells
what is competitive inhibition
similar shape to substrate and fits into active site.
-forms an enzyme inhibitor complex.
what is non-competitive inhibition
different shape to substrate and changes shape of active site
what is end point inhibition
in a series of reactions a product may inhibit the enzyme that controls ther first step of the reation this stops waste resources.
what are reversible inhibitors
constantly bind, unbind and rebind and do not permanently change shape of active site.
what are irreversible inhibitors
form a covalent bond, altering the tertiary structure.
what is an example of an irreversible inhibitor
potassium cyanide -inhibitor of a respiratory enzyme leading to lactic acid build up.
what is an immobilized enzyme
enzymes fixed to an inert matrix holding an enzyme in place during a reaction.
what does an enzyme do to an enzymes stability
increases, as without any small fluctuations of temp and ph. can denature.
how does immobilised enzymes allow enzymes to become more tolerable to a range of PH.
bonds with the insoluble material.
what are advantages of immobilised enzymes
-stability over temp and PH.
-enzyme more easily serperated from product and doesnt contaminate this product.
-enzymes with different optimum PH or temp can be used together for greater rate of productivity.
-by adding or removing enzymes, the progress of reaction can be controlled.
what are some methods of immobilising enzymes.
-absorption into an inert matrix or collagen mesh.
-held on a gel membrane
-trapped in a microcapsule e.g alginate beads.
-attracted to cellulose fibres.
what are 3 uses of immobilised enzymes in industry
-lactose free milk.
-sweeteners
-fruit juice
what are biosensors
accurately measure a quantity of a substance even at low conc. they have a biological recognition layer that contain an enzyme that can bind to the specific molecule.
how are immobilised enzymes used in test strips.
immobilised enzyme glucose oxidase detect presence of glucose in a urine sample.
biological digital biosensor
measures amount of a specific substance by converting a chemical signal into an electrical signal. -glucose oxidase sensor used for testing blood.
what is a transducer
chemical change converted into an electrical signal meausred on a meter. Strenght of signal is quivelant to conc of substance.
