Biotechnology and genetic modification
Biotechnology and fermenters
Biotechnology uses living organisms to make useful products. Microorganisms are ideal: they reproduce rapidly, need simple nutrients, and can make complex molecules. Yeast makes ethanol for biofuel and CO₂ to make bread rise. Bacteria make yoghurt (Lactobacillus turns lactose into lactic acid). Enzymes from microbes are used in biological washing powders, pectinase for clearer fruit juice and lactase for lactose-free milk. Industrial fermenters grow microbes in controlled conditions: temperature, pH, oxygen, nutrients, and stirring, kept sterile; penicillin is made this way.
≈ 35 minGenetic modification
Genetic modification changes an organism's DNA by inserting a gene from another organism. To make human insulin: the gene is cut out with restriction enzymes, leaving sticky ends; a bacterial plasmid is cut with the same enzyme; DNA ligase joins the gene into the plasmid (recombinant plasmid); the plasmid is put into bacteria, which multiply in fermenters and make insulin. GM crops can be pest-resistant, herbicide-resistant or have added nutrients (Golden Rice, vitamin A). Concerns include effects on wild populations and food safety.
≈ 35 min