Option B: Biotechnology and bioinformatics

Option B: Biotechnology and bioinformatics

Core

B.1 Microbiology: organisms in industry

Nature of science:

  • Serendipity has led to scientific discoveries - the discovery of penicillin by Alexander Fleming could be viewed as a chance occurrence.

Understandings:

  • Microorganisms are metabolically diverse.

  • Microorganisms are used in industry because they are small and have a fast growth rate.

  • Pathway engineering optimizes genetic and regulatory processes within microorganisms.

  • Pathway engineering is used industrially to produce metabolites of interest.

  • Fermenters allow large-scale production of metabolites by microorganisms.

  • Fermentation is carried out by batch or continuous culture.

  • Microorganisms in fermenters become limited by their own waste products.

  • Probes are used to monitor conditions within fermenters.

  • Conditions are maintained at optimal levels for the growth of the microorganisms being cultured.

Applications and skills:

  • Application: Deep-tank batch fermentation in the mass production of penicillin.

  • Application: Production of citric acid in a continuous fermenter by Aspergillus niger and its use as a preservative and flavouring.

  • Application: Biogas is produced by bacteria and archaeans from organic matter in fermenters.

  • Skill: Gram staining of Gram-positive and Gram-negative bacteria.

  • Skill: Experiments showing zone of inhibition of bacterial growth by bactericides in sterile bacterial cultures.

  • Skill: Production of biogas in a small-scale fermenter.

B.2 Biotechnology in agriculture

Nature of science:

  • Assessing risks and benefits associated with scientific research - scientists need to evaluate the potential of herbicide resistance genes escaping into the wild population.

Understandings:

  • Transgenic organisms produce proteins that were not previously part of their species’ proteome.

  • Genetic modification can be used to overcome environmental resistance to increase crop yields.

  • Genetically modified crop plants can be used to produce novel products.

  • Bioinformatics plays a role in identifying target genes.

  • The target gene is linked to other sequences that control its expression.

  • An open reading frame is a significant length of DNA from a start codon to a stop codon.

  • Marker genes are used to indicate successful uptake.

  • Recombinant DNA must be inserted into the plant cell and taken up by its chromosome or chloroplast DNA.

  • Recombinant DNA can be introduced into whole plants, leaf discs or protoplasts.

  • Recombinant DNA can be introduced by direct physical and chemical methods or indirectly by vectors.

Applications and skills:

  • Application: Use of tumour-inducing (Ti) plasmid of Agrobacterium tumefaciens to introduce glyphosate resistance into soybean crops.

  • Application: Genetic modification of tobacco mosaic virus to allow bulk production of Hepatitis B vaccine in tobacco plants.

  • Application: Production of Amflora potato (Solanum tuberosum) for paper and adhesive industries.

  • Skill: Evaluation of data on the environmental impact of glyphosate-tolerant soybeans.

  • Skill: Identification of an open reading frame (ORF).

B.3 Environmental protection

Nature of science:

  • Developments in scientific research follow improvements in apparatus - using tools such as the laser scanning microscope has led researchers to deeper understanding of the structure of biofilms.

Understandings:

  • Responses to pollution incidents can involve bioremediation combined with physical and chemical procedures.

  • Microorganisms are used in bioremediation.

  • Some pollutants are metabolized by microorganisms.

  • Cooperative aggregates of microorganisms can form biofilms.

  • Biofilms possess emergent properties.

  • Microorganisms growing in a biofilm are highly resistant to antimicrobial agents.

  • Microorganisms in biofilms cooperate through quorum sensing.

  • Bacteriophages are used in the disinfection of water systems.

Applications and skills:

  • Application: Degradation of benzene by halophilic bacteria such as Marinobacter.

  • Application: Degradation of oil by Pseudomonas.

  • Application: Conversion by Pseudomonas of methyl mercury into elemental mercury.

  • Application: Use of biofilms in trickle filter beds for sewage treatment.

  • Skill: Evaluation of data or media reports on environmental problems caused by biofilms.

Additional higher level

B.4 Medicine

Nature of science:

  • Developments in scientific research follow improvements in technology - innovation in technology has allowed scientists to diagnose and treat diseases.

Understandings:

  • Infection by a pathogen can be detected by the presence of its genetic material or by its antigens.

  • Predisposition to a genetic disease can be detected through the presence of markers.

  • DNA microarrays can be used to test for genetic predisposition or to diagnose the disease.

  • Metabolites that indicate disease can be detected in blood and urine.

  • Tracking experiments are used to gain information about the localization and interaction of a desired protein.

  • Biopharming uses genetically modified animals and plants to produce proteins for therapeutic use.

  • Viral vectors can be used in gene therapy.

Applications and skills:

  • Application: Use of PCR to detect different strains of influenza virus.

  • Application: Tracking tumour cells using transferin linked to luminescent probes.

  • Application: Biopharming of antithrombin.

  • Application: Use of viral vectors in the treatment of Severe Combined Immunodeficiency (SCID).

  • Skill: Analysis of a simple microarray.

  • Skill: Interpretation of the results of an ELISA diagnostic test.

B.5 Bioinformatics

Nature of science:

  • Cooperation and collaboration between groups of scientists - databases on the internet allow scientists free access to information.

Understandings:

  • Databases allow scientists easy access to information.

  • The body of data stored in databases is increasing exponentially.

  • BLAST searches can identify similar sequences in different organisms.

  • Gene function can be studied using model organisms with similar sequences.

  • Sequence alignment software allows comparison of sequences from different organisms.

  • BLASTn allows nucleotide sequence alignment while BLASTp allows protein alignment.

  • Databases can be searched to compare newly identified sequences with sequences of known function in other organisms.

  • Multiple sequence alignment is used in the study of phylogenetics.

  • EST is an expressed sequence tag that can be used to identify potential genes.

Applications and skills:

  • Application: Use of knockout technology in mice to determine gene function.

  • Application: Discovery of genes by EST data mining.

  • Skill: Explore chromosome 21 in databases (for example in Ensembl).

  • Skill: Use of software to align two proteins.

  • Skill: Use of software to construct simple cladograms and phylograms of related organisms using DNA sequences.

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