Saccharomyces cerevisiae is Brewer’s Yeast This is the same yeast that is used to leaven bread and ferment alcohol in beer and wine http://www.cosmopolitan.com/health-fitness/news/a35091/

Saccharomyces cerevisiae is a Model Organism Model organisms are used to study biological processes, with the hopes of extrapolating results to humans. They are less expensive to maintain, reproduce faster, and raise fewer ethical questions. https://biology.uiowa.edu/model-organisms

Yeast are Eukaryotic Yeast is a fungus. This makes it more closely related to humans than to bacteria, which are prokaryotic. https://commons.wikimedia.org/wiki/File:Tree_of_Living_Organisms_2.png

But…yeast?! Yeast, unlike humans, is unicellular. But, like human cells, yeast: Has linear chromosomes Must respirate Must consume food Must sense the environment surrounding its cells Must arrest its growth in response to internal and environmental cues http://mycor.nancy.inra.fr/blogGenomes/wp-content/uploads/2010/05/wheals21.gif

Yeast Can Grow on Liquid or Solid Media Yeast growth medium (YPD) includes proteins, yeast extract, and glucose. YPD solid media also includes agar. https://bmcresnotes.biomedcentral.com/articles/10.1186/1756-0500-4-74 https://sciencebrewer.files.wordpress.com/2012/04/dsc_0357.jpg

Yeast Reproduce by Budding Look for budding today Yeast reproduce asexually by budding, but can reproduce sexually if the opportunity arises. http://book.bionumbers.org/how-big-is-a-budding-yeast-cell/

Today’s Experiment Methylene Blue Viability Assay Our way to testing viability in your projects

Methylene Blue Viability Assay Unlike Trypan Blue, all cells take up Methylene Blue However, living cells reduce Methylene Blue making it colorless How? Living cells undergoing glycolysis produce NADH, which reduces Methylene Blue Oxidized Dead Reduced Alive NADH Methylene Blue Dead Cell Living Cell braukaiser.com