Related Concept Videos

Structure of Lipids03:38

Structure of Lipids

Lipids include a diverse group of compounds that are largely nonpolar in nature. This is because they are hydrocarbons that include mostly nonpolar carbon-carbon or carbon-hydrogen bonds. Non-polar molecules are hydrophobic (“water fearing”), or insoluble in water. Lipids perform many different functions in a cell. Cells store energy for long-term use in the form of fats. Lipids also provide insulation from the environment for plants and animals. For example, they help keep aquatic birds and...
Production of Pharmaceuticals01:30

Production of Pharmaceuticals

Industrial insulin production uses genetically engineered E. coli expressing a proinsulin gene controlled by a tryptophan promoter and containing a methionine linker for later cleavage. The cells also carry ampicillin resistance for selective growth. Seed cultures are stored at −80 °C and production begins by thawing a small amount to inoculate starter cultures, which are progressively scaled to a 50,000-L bioreactor. In the bioreactor, E. coli grow in nutrient-rich media under sterile, tightly...
Downstream Processing01:29

Downstream Processing

Downstream processing begins once fermentation is complete and involves a series of steps to recover and purify products such as acids, vitamins, antibiotics, or proteins.Cell HarvestingFor example, for intracellular protein-based products, the first step is harvesting the cells. This is typically achieved using centrifugation or filtration to separate the cells from the liquid phase.Cell Disruption for Intracellular ProductsIf the target product is intracellular, the harvested cells must be...
Lipids: Dietary Sources and Requirements01:18

Lipids: Dietary Sources and Requirements

Lipids are an essential component of a balanced human diet. Triglycerides, which make up the majority of dietary lipids, are found in both saturated fats—commonly present in meat, dairy products, and certain tropical plants like coconut, and hydrogenated oils such as margarine and baking shortenings (trans fats)—and unsaturated fats, which are abundant in seeds, nuts, olive oil, and most vegetable oils. The main sources of cholesterol include egg yolks, various meats and organ meats, shellfish,...
Pasteurization and Food Preservation01:28

Pasteurization and Food Preservation

Pasteurization is a widely employed thermal processing technique designed to enhance the safety and shelf life of perishable food and beverages. By subjecting products to specific high temperatures for controlled durations, this method effectively inactivates pathogenic microorganisms and spoilage enzymes without significantly compromising sensory qualities. The technique has been pivotal in food safety management, especially for consumables susceptible to microbial contamination such as milk,...