First 656 words of the document:
Use of Enzymes These changes can be converted into electrical
There are many ways in which enzymes can be signal by a transducer and the strength of the
Enzyme Uses: immobilised. signal is proportional to the concentration of the
Enzymes are used in many industries. - Placed on an insoluble matrix. substance being measured.
- The food industry. - Held inside a gel, such as silica gel.
- Pharmaceutical industry. Biosensors to Detection Glucose Levels:
- Held within a semi-permeable The biosensor uses enzymes and a transducer.
- Agrochemical industry. membrane. The transducer produces an electrical signal in
One use of enzymes in the medical industry is - Trapped inside a microcapsule, such as response to the substrate being transformed into
biosensors. alignate beads. the product.
These are a type of immobilised enzymes. - Attached to cellulose fibres. The electrical signal is then measured with a
Immobilised Enzymes: Applications of Enzymes: The electrode probe has an immobilised enzyme
- Enzymes have been used in industry for The enzymes are enmeshed in a matrix or inert in the membrane.
many years and their use is increasing on solid support. This is placed in the blood. If glucose is present it
a commercial scale. This makes them much easier to reuse and can diffuse through the membrane and forms an
- Enzymes that have been used in the improves stability to external conditions. enzyme-substrate complex.
previous years have been used for one This reaction produces a current which is
reaction and than wasted. It would Advantages and Disadvantages: detected by the electrode and the strength of the
obviously be more economic to retain the Advantages Disadvantages current is read by the meter.
enzyme and so be able to re-use. This gives the reading for blood glucose levels
- However, this is a problem as the Easier to separate Immobilisation may which ideally should be between 3.89 and
enzyme would often become mixed in enzyme and product. alter shape of enzyme. 5.83mm dm-3.
with the end products and it was Allows catalysis in May alter catalytic
expensive and time-consuming to purify unfavourable media. ability. Steps in using a Biosensor:
it. Increases stability and Enzyme may become 1. Blood mixture of different molecules.
- There was a demand for enzymes that can be manipulated detached. 2. Enzyme electrode placed in blood
could be used again and again where the easily. sample.
product would be pure and Allows continuous Expensive 3. Glucose diffuses into the immobilised
uncontaminated by any enzyme. production/enzyme enzyme layer.
- However, the enzyme needs to be in used for longer 4. Oxygen is taken up.
contact with the substance in order to Enzymes can be 5. The rate of oxygen uptake is proportional
react. recovered and reused. to the glucose concentration.
Enzyme doesn't 6. The concentration of glucose I displayed
- The solution to this dilemma is to use digitally.
immobilised enzymes which are contaminate the
attached to a surface that is inert product/no purification
- They are NOT allowed to dissolve into
the solution and are held in place during Biosensors:
the reaction. In a biosensor there is a biological recognition
- This means that the enzymes can be layer which contains an enzyme.
removed at the end of the reaction and The enzyme here behaves as an analytical
can be used again, also they do not reagent and is used to recognise a particular
contaminate the end product at all. substance.
- This also has the result that a lot of It relies on the fact that when two chemicals
product can be made from a relatively interact there are measurable chemical changes.
small amount of enzyme.