Zusammenfassung der Ressource
Enzymes
- An enzyme is a protein catalysts
that speeds up a reaction without
being used up in the reaction
- Active site Theory of Enzyme Action
- The active site of an enzyme is the
area where the substrate enters and is
changed into a product
- Specificity refers to an enzyme's ability
to react with only one substrate
- The lock and key model
- Enzyme has a
rigid shape and
substrate fits
into active site
- The Induced fit Model
- The substrate(s) does not fit perfectly into
active site but the active site is flexible
- Active site changes shape to fit substrate, enzymes
active site acts on substrate to convert it to a
product
- Product is released and active site changes back to its original shape
- Factors affecting Enzyme Action
- Temperature
- Above a certain temp. the enzyme
loses its shape and its ability to
function. It is said to be denatured
- As the temp. rises, molecules move faster. This causes
enzymes and substrate molecules to collide more often. For
this reason the rate of enzyme reaction increases with temp.
- It's optimum temperature 37 ºC
- pH
- Changes in pH disrupt
the enzyme's shape
- If the enzyme's shape is lost, it
cannot act on its substrate
- Bioprocessing
- is the use of enzyme-controlled
reactions to make a product
- Immobilised Enzymes
- are enzymes that are attached to
each other or to an inert substance
- Benefits
- Immobilised enzymes can be reused
- Product contains no enzyme (saves
on separation costs)
- They are as efficient as isolated enzymes
- Uses
- Immobilised lactose breaks down lactose
in milk for lactose-tolerant people
- Immobilised glucose isomerase is used in sweet
manufacture to convert glucose to fructose
- A bioreactor is a vessel in which cells
or enzymes produce useful products