Economical enzymes:
Enzymes are very economical when used because they are not used up when they catalyse a reaction, so the same enzyme can be re used many more times.
Industrial enzymes:
In the biotechnology industry enzymes are often produced by bacteria, grown under controlled conditions in ferments.
Immobilised enzymes:
Enzymes have many industrial used, enzymes can be simply be added to a substrate mixture. but it is not east to use this enzyme again, as it would have to be separated from the product to re use it again, consequently another efficient and economical technique is to use a immobilised enzyme.
The enzyme reaction used in this practical:
I will immobilise the lactase enzymes by trapping it within beads of sodium alginate. Then I will use the immobilised lactase enzyme to make lactose free milk.
Risk assessment:
Although lactase is a reasonably safe enzyme, I handle it with care and also rinsed my hands after I had come in contact with it.
The method;
Using a 10cm³ plastic syringe I transferred 2cm³ of lactase into a beaker which contained 8cm³ of 2% of sodium alginate solution. Then I filled another beaker with 100cm³ of calcium chloride. After that I carefully drew the lactose mixture in to a 20cm³ syringe, I then placed the syringe into the retort stand to help me hold it in place. Once squarely in place I placed the beaker containing calcium chloride underneath the syringe making sure the syringe was at a good height so the beads are able to form nicely.
Once the beads were formed I separated them from the calcium chloride solution using a tea strainer.
Placing a piece of gauze in to 10cm³ plastic syringe to help prevent blocking the nozzle of the syringe and closed the clip on the plastic tubing and then placed it into the retort stand . Furthermore I then carefully tipped the beads into the 10cm³ syringe. But before I poured the fresh cows milk into the syringe, I had tested the milk for glucose using a clinistix. I placed the clinistix into the beaker containing the milk for about 10sec and took it out I then tapped the clinistix at the side of the beaker to take of any excess milk. I have also carry out carried out this test for cat’s milk. The three different colours the clinistix change are pink, blue and purple. If the stick stayed pink this meant no glucose is present, if the stick turned blue a little glucose was present and if the colour purple was present this meant their was a lot of glucose present.
I carefully poured the milk very slowly into the top of the syringe, so that it passes through the beads. I then opened the clip on the plastic tubing and collected the lactose free milk into a clean beaker.
I then tested the milk which I had collected in to the beaker, weather to see if glucose was present using a clinistix.
Results:
Cows milk test for glucose:
Whiskas Cats milk test for glucose:
In this experiment when I mixed together lactose and sodium alginate along with calcium chloride I had attained hard beads. This is due to calcium ions displacing the sodium ions which form hard beads of calcium alginate.
Also the beads were form in to little balls; this is helpful due to if the beads were formed square or oval each of the shape would have locked itself together and would not have allowed the milk to flow through.
The conclusion:
In this experiment I have immobilised lactase enzyme by locking them into small rounded beads. When the mixture of lactose and sodium alginate is dropped into the calcium chloride solution, the calcium ions displaced the sodium ions, which than formed calcium alginate. This contained lactase enzymes, lactase enzymes are immobilised so that it can be used to breakdown the lactose in the milk and also to convert it to glucose and galactose. This immobilised lactase enzyme is used to breakdown lactose in milk, in order to help lactose intolerant people and animals to drink milk, without having to suffer wind, diarrhoea and abdominal cramps. They can not drink normal milk due to they do not have the lactase enzyme in their system.
Before adding milk to the calcium alginate beads, I tested if glucose was present using clinistix. This stick tests how much glucose is present by changing colour according to how much glucose is present in the milk. Before I added milk to the calcium alginate, I tested it to see if glucose was present; the stick stayed pink which meant no glucose was present. But when I tested the milk again after it had passed through the beads the clinistix tip turned purple telling me that there is a lot of glucose present in my milk. In addition I think that lactase enzymes are trapped within the calcium alginate beads reacted with the lactose in the milk converting it init glucose and galactose, which was then collected into my beaker.
The equation
Lactose Glucose + Galactose
The enzyme lactase is for the break down of lactose because it is the only enzyme that able to convert lactose into glucose and galactose.
The evaluation:
Overall I think this experiment went very well, if I was to repeat this experiment I will carry out same method I used as it was straightforward.
However the only disadvantage I came across was that there was no easy way of testing if lactose is present before or after the experiment, I would want to test for lactose before and after the experiment due to tell weather lactose was present and if I have successfully removed. Also the formation of the beads was better as they were round and not square and oval, as it was helped the milk passed through easier, however if I had obtained square beads they would have locked them self together and not let no milk pass through and if I has formed oval beads their would have been a very large surface area which also means that milk would not be able to pass through. This was the most difficult part of the experiment as the height of the syringe and retort stand had to be just right to help form the bead the right shape. Furthermore using a retort stand and clamp had helped me out a lot as the formation of the beads took a very long time.
