Did you know that yeast is a living being? Like us humans, yeast absorbs food, goes to the “loo” and breathes, so it has a metabolism. Yeast is a fungus and consists of individual living cells. It is a microorganism that is so tiny that we cannot even see it with the naked eye.
But how can you show that yeast fungi are also alive without a microscope? Do the yeast balloon experiment and find out!
If you dissolve the single-cell yeast fungi in warm water and feed them sugar, the yeast produces CO2, i.e. the gas carbon dioxide, through digestion. Gas needs a lot of space. This causes the balloon to expand and become inflated.
As long as the yeast still has sugar as food and oxygen to breathe, it produces CO2, which is called aerobic metabolism. Incidentally, unlike humans, yeast can continue to live without oxygen. However, it does not produce CO2, but alcohol. This happens, for example, in the production of beer.
To inflate the balloon, the yeast needs its favorite food: sugar. After all, it has quite a sweet tooth.
In addition to your control experiment without sugar, you can carry out further tests.
Die Hefe hat es gerne lauschig warm, da fühlt sie sich am wohlsten.
People use yeast for sourdough to make bread. Sourdoughs from all over the world are stored in the Puratos sourdough library in Belgium. Instead of bookshelves, refrigerators are lined up next to each other. Over 700 wild yeast strains are registered in this library!
Yeast can help scientists in their experiments, not only for the production of delicious bread and pastries in the kitchen, but also in the laboratory.
For example, yeast is a tool for producing certain proteins. To do this, the researchers insert a gene for the desired protein into the yeast. The gene carries the building instructions for the protein. The yeast then uses these instructions to build the protein from individual building blocks, the amino acids. You can think of it like the bricks of a house. Yeast cells are therefore microscopic bricklayers in the service of scientists.
The Sazanov group at ISTA, for example, is researching membrane proteins produced in this way. This basic research is intended to help cure certain diseases.
