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Eukaryotic flagella are ATP-driven, while prokaryotic flagella can be ATP-driven (archaea) or proton-driven (bacteria). [22] Different types of cell flagellation are found depending on the number and arrangement of the flagella on the cell surface, e.g., only at the cell poles or spread over the cell surface. [23]
In comparison to eukaryotes, the intracellular features of the bacterial cell are extremely simple. Bacteria do not contain organelles in the same sense as eukaryotes. Instead, the chromosome and perhaps ribosomes are the only easily observable intracellular structures found in all bacteria. There do exist, however, specialized groups of ...
Spiral bacteria are another major bacterial cell morphology. [2] [30] [31] [32] Spiral bacteria can be sub-classified as spirilla, spirochetes, or vibrios based on the number of twists per cell, cell thickness, cell flexibility, and motility. [33] Bacteria are known to evolve specific traits to survive in their ideal environment. [34]
They can be classified into different types based on their specific structure, composition and activity. Generally, proteins can be secreted through two different processes. One process is a one-step mechanism in which proteins from the cytoplasm of bacteria are transported and delivered directly through the cell membrane into the host cell.
The term "bacteria" was traditionally applied to all microscopic, single-cell prokaryotes. However, molecular systematics showed prokaryotic life to consist of two separate domains, originally called Eubacteria and Archaebacteria, but now called Bacteria and Archaea that evolved independently from an ancient common ancestor. [5]
Gram negative Neisseria gonorrhoeae and pus cells. Gram-negative bacteria generally possess a thin layer of peptidoglycan between two membranes (diderm). [26] Lipopolysaccharide (LPS) is the most abundant antigen on the cell surface of most gram-negative bacteria, contributing up to 80% of the outer membrane of E. coli and Salmonella. [27]
Bacteria in Cytophagales are all Gram-negative and non-spore forming. [10] [4] [11] They are non-flagellated, but move by exhibiting a gliding or flexing motion. Cytophagales are all unicellular, with rod-shaped cells that can differ significantly in shape. [10] Cells can be short or long, delicate or stout, and have tapering or rounded ends.
Bacterial morphological plasticity refers to changes in the shape and size that bacterial cells undergo when they encounter stressful environments. Although bacteria have evolved complex molecular strategies to maintain their shape, many are able to alter their shape as a survival strategy in response to protist predators, antibiotics, the immune response, and other threats.