Saccharomyces cerevisiae is one of the most well-known yeasts used in microbiological studies and the food industry. It is a unicellular fungus and a eukaryotic organism, meaning that its cells contain a true nucleus and various organelles. The cells are usually oval or relatively round in shape and are characterized by their ability to reproduce asexually through budding. During this process, a small bud develops on the parent cell as a result of genetic material division and the distribution of cellular components. The bud then continues to grow until it separates from the parent cell or remains attached for a period of time. Yeast differs from bacteria in its cellular structure because it possesses a true nucleus and membrane-bound organelles, whereas bacteria lack a true nucleus. One of the most important metabolic characteristics of this yeast is its ability to consume sugars and produce ethanol and carbon dioxide under fermentation conditions. For this reason, it is widely used in bread making and various food and fermentation industries. Carbon dioxide produced during dough fermentation contributes to the formation of the spaces that make bread rise and become more porous, while ethanol represents one of the main products of fermentation. S. cerevisiae has also become one of the most important model organisms in scientific research, where it is used to study the cell cycle, cell division, gene expression, and metabolic processes. It can also be genetically modified and used to produce certain proteins and compounds of technological value. In addition, it is relatively easy to culture, preserve, and study, which has made it a fundamental model organism in cellular and molecular biology. Therefore, the study of baker’s yeast provides a clear example of how a microorganism can move from being a microscopic subject of study to becoming an important component of food, industry, and scientific research.