Since prokaryotes consist of great diversity, they obtain energy from inorganic compounds like hydrogen sulfide in addition to photosynthesis and organic compounds. Rod-like structures called pili allow the genetic transfer. Bacterial gene transfer occurs in three methods: transduction mediated by bacteriophages, conjugation mediated by plasmids, and natural transformation. The sexual reproduction method of prokaryotes is the horizontal gene transfer. Some DNA pieces can be found in the cytoplasm as circular plasmids.Īsexual reproduction of prokaryotes occurs via binary fission. Bacteria consist of a single circular chromosome. Genomic DNA is found in a region called nucleoid in the cytoplasm. Small 70S ribosomes are present for protein synthesis. They consist of a primitive cytoskeleton. The structure of a prokaryotic cell is shown in figure 1.īacterial cytoplasm is a gel-like substance which dissolves a variety of organic molecules. Some bacteria consist of a glycocalyx which covers the cell membrane surroundings. Fimbriae, which is a numerous hair-like structure, also helps the attachment.
Flagella, a wipe-like structure, help the movement of the cell. Some bacteria possess an outermost layer called capsule which is sticky, helping the cell to attach to surfaces. Cell wall provides protection to the cell, maintains the shape and prevents dehydration. The bacterial cell wall is made up of peptidoglycans. Bacteria and cyanobacteria are the two types of prokaryotes.įour types of shapes can be identified in bacteria: spherical-shaped (cocci), rod-shaped (bacilli), spiral-shaped (spirochaete) and comma-shaped (vibrio). Though prokaryotes do not contain compartments called organelles in the cytoplasm, they still process some microcompartments, which act as primitive organelles. The cell membrane of prokaryotes encloses water-soluble proteins, DNA, and metabolites in the cytoplasm. Most prokaryotes are 0.2 to 2 µm in size. All prokaryotes are unicellular organisms. Prokaryotes refer to the organisms that do not have a nucleus and membrane-bound organelles. Key Terms: Animals, Bacteria, DNA, Eukaryotes, Fungi, Membrane-Bound Organelles, Nucleus, Plants, Prokaryotes What is the Difference Between Prokaryotes and Eukaryotes What are the Similarities Between Prokaryotes and EukaryotesĤ. Eukaryotic organisms include animals, plants, fungi, algae, and protozoa. Prokaryotic organisms include bacteria and cyanobacteria. The other organelles in eukaryotes are mitochondria, chloroplast, endoplasmic reticulum, Golgi apparatus, and lysosomes. But in eukaryotes, DNA is organized into a membrane-enclosed organelle called nucleus. The genetic material of prokaryotes can be found in a specific location of the cytoplasm, which is called nucleus. The main difference between prokaryotes and eukaryotes is that prokaryotes do not have membrane-enclosed organelles whereas eukaryotes have membrane-enclosed organelles.
Prokaryotes and eukaryotes are the two organizational levels of living organisms on earth. Main Difference – Prokaryotes vs Eukaryotes
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