The purpose of this lab was to determine the size of prokaryotic microbes in comparison to eukaryotic cells. Students used oil immersion microscopy to magnify the microbes and compare their size to that of a eukaryotic cheek cell. The results of this lab allowed students to compare and contrast eukaryotic and prokaryotic cell size, which is a necessary skill when working with microbiology based labs. Microbiology is the study of microscopic organisms, also known as microbes. Microorganisms include bacteria, fungi, protists, and autotrophic organisms. Viruses, although not an organism, are often included in the study of microbes. In this lab, three types of bacteria; bacillus, spirillum, and coccus; were observed and compared to eukaryotic cheek cells. This research question successfully related to students’ classroom lectures about the topic of microbiology. Comparing the size of prokaryotic microbes to eukaryotic cells gave students a better understanding of the classification of organisms, including the three domains as well as the six kingdoms, and the relative size and structural characteristics of each classification. Observing and illustrating the sizes and shapes of the microbes also provided students with a real life application of the shapes and arrangements of bacteria, which were discussed in class.
Many previous experiments have worked with microbes because although microbes are invisible to the naked eye, when they are magnified, they introduce a world of bacteria that influences much of life. Robert Hooke was the first person to discover cells in 1660. Just sixteen years later, in 1676, Leeuwenhoek became the first scientist to discover microorganisms. Leeuwenhoek observed and described microscopic bacteria from rainwater using simple magnifications. Over the next hundreds of years, microscopy, specifically oil immersion microscopy, became the basis of studying and understanding microbes. Oil immersion microscope lens increases the resolution of a microscope. As early as 1812, Sir David Brewster “suggested that the front element of a microscope’s objective lens could be immersed in the liquid in which the object of study was mounted” (Magner, 148). In 1840, Giovanni Amici advanced the immersion technique and introduced oil immersion, in which the objective lens touches a drop of oil placed on the cover slip. This technique was championed with the goal of minimizing light aberrations to produce a more focused view.
Understanding the differences between prokaryotic and eukaryotic cells is the underlying concept in comparing the size of the prokaryotic bacteria and the eukaryotic cheek cell. The differing structure and containments of prokaryotic and eukaryotic cells help to explain their contrasting size. Prokaryotic cells do not contain membrane-bound organelles, such as the nucleus. In addition to having different organelles, the cell structure varies between prokaryotes and eukaryotes. Not all eukaryotic cells are...