1. 12 September 201812 September 2018 Title: Industrial Enzymes
Homework: learning package 12 due today

2. Learning Outcomes (d) describe how enzymes can be immobilised;
(e) explain why immobilised enzymes are used in large-scale production

3. Immobilising enzymes Enzymes act as catalysts in metabolic reactions
Enzymes are useful in industrial processes
Specificity
Temperature of enzyme action
Enzymes in solution need to be separated from the products.
Expensive
Time consuming
Immobilised enzymes can be re-used many times and leaves the product enzyme free.

4. Methods for immobilising enzymes
Gel entrapment
Example – immobilising lactase in alginate
Stages
Enzyme solution is mixed with sodium alginate solution
Droplets of this solution are added to a solution of calcium chloride
The droplet turns into a bead which contains the enzyme

5. Immobilising lactase in alginate

6. Immobilising lactase in alginate
The beads can be tightly packed into a column
The liquid substrate can be trickled over the beads
The product trickles out of the bottom of the column
The product is collected and purified.

7. Methods of immobilising enzymes
Adsorption / carrier bound
Enzyme molecules are mixed with immobilising support e.g. glass beads or clay
Covalent Bonding / cross-linked
Enzyme molecules covalently bonded to a support

8. Methods of immobilising enzymes
Entrapment / inclusion
Enzymes trapped in their natural state in a gel bead
Reaction rate can be reduced as substrate needs to get through the trapping barrier
Membrane separation
Substrate separated from the mixture by a partially permeable membrane.

9. Advantages of immobilised enzymes
The advantages of using immobilised enzymes over enzymes in solution are:
Immobilised enzymes can be reused – reduces cost of running on an industrial scale because you don’t have to keep buying new enzymes
Product is enzyme free – no money/time spent separating them out
Immobilised enzymes are more tolerant to pH and temperature changes

10. Questions
Compare and contrast the different methods of immobilising enzymes
Explain how covalently bonding enzymes to a support could completely remove the enzymes’ activity.
Suggest and explain the features of bacterial cells that are most likely to be the target of the antibiotic chemicals that would be of most use to human medicine.

11. To do…
Read pages
Answer questions on page 167

12. DNA Evidence for Evolution
 Deoxyribonucleic acid (DNA) codes for proteins that your body needs to live. Two of those proteins are the alpha and beta hemoglobin proteins that occur in your blood. These proteins carry oxygen and carbon dioxide as they circulate in your bloodstream.
Other animals’ blood also contains α and β hemoglobin proteins. However, not all of these proteins are identical. The differences between α and β hemoglobin proteins are caused by differences in the DNA that codes for them.
One reason why developmental biologists are interested in comparing the DNA and proteins of organisms is to learn about relatedness.
The more similar two organisms’ DNA are, the more likely it is that the organisms are closely related.
Process and Procedures
The following sequences of letters stand for the DNA bases from portions of the genes that code for alpha and beta hemoglobin proteins.
1. Compare the DNA sequences from the α hemoglobin for two different primates. Calculate the percent for how similar the bush baby α hemoglobin DNA sequence is to Homo sapiens.
% similar = (numb. DNA bases the same ÷ total numb. DNA bases) × 100
2. Compare the DNA sequences from the β hemoglobin of four different primates. Calculate the percent for how similar each β hemoglobin DNA sequence is to Homo sapiens.