Eukaryote and Prokaryote Bacterial Cells

Introduction

A cell is the smallest unit in all living organisms that replicates autonomously. Life is classified in the following kingdoms: bacteria, plants, fungi, animals and protoctista. The difference between the eukaryotic organisms and the prokaryotic organisms is considerably the most significant distinction amongst the organisms (Tortora et al., 2002). Many years ago the prokaryotic organisms were the sole life form on Earth. However, the eukaryotic organisms emerged through evolution over time. The purpose of this essay is to delve into the functional anatomical dissimilarities between the eukaryote and the prokaryote cells. The paper will further provide a succinct analysis of processes through which the substances travel across the cell membranes.

Functional Anatomical Dissimilarities

Prokaryotes are the cells that have no nucleus unlike eukaryotes. Plants, fungi, animals, and protoctista are eukaryotes while bacteria are prokaryotes. Prokaryotes have a single circular chromosome with no membrane while eukaryotes have paired chromosomes with a nuclear membrane. Again, prokaryotes have no histones and membrane-bound organelles but eukaryotes have histones and organelles. Additionally, the cell walls of prokaryotes are made of peptidoglycan while those of eukaryotes are made of polysaccharides. While prokaryotes reproduce through binary fission, the eukaryotes reproduce through mitotic spindle (Whaley & Sousa, 2012).

Unlike prokaryotic organisms, eukaryotes have a multifarious cell structure. As the single-celled organisms, prokaryotes lack general cell components. Without cell organelles, prokaryotic cells do not need any cell membrane like eukaryotic organisms. This simplifies the complexities while feeding, reproducing, and surviving in certain habitats for the prokaryotic organisms. On the other hand, eukaryotes are multi-cellular living organisms with complex cells. They have cell organelles in their cell membranes. The organelles in eukaryotes have dissimilar functions that bolster the capacity of organisms to feed and reproduce. Most organelles in eukaryotes are specialized and this enhances their efficiency during reproduction and feeding (Tortora et al., 2002). Prokaryotic cells are always unicellular with small ribosomes while eukaryotic cells are often multicellular with large ribosomes. Additionally, prokaryotes have no cytoskeleton as opposed to eukaryotes that have a cytoskeleton.

The ‘true’ nucleus containing Deoxyribonucleic Acid (DNA) in the cell membranes of eukaryotic organisms differentiates eukaryotes from prokaryotes. In eukaryotic organisms, the chloroplasts and mitochondria execute an avalanche of metabolic processes. In prokaryotes, the related processes occur athwart cell membrane. The eukaryotic cells are relatively small compared to the prokaryotic cells. Eukaryotes differ from eukaryotes in packing, arrangement, structure as well as density of the chromosomal genes. Prokaryotes have a diameter of 0.2-2.0μ m while eukaryotes have a diameter of about 10-100μ m. In terms of fragella, prokaryotes have building blocks made of proteins while eukaryotes have multiple microtubules (Whaley & Sousa, 2012). Motility in prokaryotes is by a rotating fragellum while in eukaryotes it is by fragellae or waving cilia. Moreover, the glycocalyx in prokaryotes have a slime layer or a capsule while the glycocalyx in eukaryotic organisms have no cells.

The cell membrane in prokaryotes is selectively permeable. This allows the selected substances to pass through in order to guarantee the survival of cells. The cell membranes permit active transport for specific molecules through the membrane either out or into the cells. Certain molecules are permitted to move against the concentration (Tortora et al., 2002). Active transport requires plenty of energy. The contents in secretory vesicles travel from and into the plasma membrane through exocytosis and endocytsis respectively. Solid substances travel across the cell membrane via phagocytosis. Oftentimes, the cell membranes have receptor sites that allow interaction with certain biochemicals like neurotransmitters, immune proteins as well as certain hormones. Protein markers in the plasma membrane facilitate communication of nearby cells. Group translocation occurs in certain prokaryotes. Lipid-soluble molecules like water, oxygen, steroids, and carbon dioxide move through diffusion across the membrane.

Conclusion

All the living organisms have cells. The organisms are classified into eukaryotes and prokaryotes. As earlier mentioned, the cell division in prokaryotes occurs through binary fission and mitosis in eukaryotes. The chemical reactions as well as chemical composition in prokaryotes are the same. As demonstrated in this essay, there are clear functional anatomical dissimilarities between eukaryotic and prokaryotic bacterial cells. Lastly, the substances move across the cell membranes through diffusion, osmosis, active transport, phagocytosis, endocytosis, and the exocytosis processes.

References

Tortora, G. J., Funke, B. R., & Case, C. L. (2002). Microbiology: An introduction. San Francisco: Benjamin Cummings.

Whaley, L., & Sousa, N. (2012). Eukaryote and prokaryote organisms. Delhi: Academic Studio.