Search results
Results from the WOW.Com Content Network
Cell shape is generally characteristic of a given bacterial species, but can vary depending on growth conditions. Some bacteria have complex life cycles involving the production of stalks and appendages (e.g. Caulobacter) and some produce elaborate structures bearing reproductive spores (e.g. Myxococcus, Streptomyces).
One of the earliest prokaryotic cells to have evolved, bacteria have been around for at least 3.5 billion years and live in just about every environment imaginable. Explore the structure of a bacteria cell with our three-dimensional graphics.
Bacterial cells (prokaryotic cells) are structurally much simpler than eukaryotic cells and the two cell types are compared in Table 3.2. They consists of various cell surface structures, cell wall, plasma membrane, many cytoplasmic inclusions, and the bacterial chromosome (nucleoid).
All bacteria, both pathogenic and saprophytic, are unicellular organisms that reproduce by binary fission. Most bacteria are capable of independent metabolic existence and growth, but species of Chlamydia and Rickettsia are obligately intracellular organisms.
The structure of the bacteria consists of three major parts: Outer layer (cell envelope), cell interior, and additional structures. Outer layer (Cell envelope): It includes the cell wall of bacteria and the plasma membrane beneath it.
Only in the past 20 years, with the advent of cryogenic EM (cryo-EM), have researchers been able to visualize the internal structure of small cells like bacteria and archaea in a native, unperturbed state.
Bacterial cell have simpler internal structure. It lacks all membrane bound cell organelles such as mitochondria, lysosome, golgi, endoplasmic reticulum, chloroplast, peroxisome, glyoxysome, and true vacuole. Bacteria also lacks true membrane bound nucleus and nucleolus. The bacterial nucleus is known as nucleoid.
A cell wall is a layer located outside the cell membrane found in plants, fungi, bacteria, algae, and archaea. A peptidoglycan cell wall composed of disaccharides and amino acids gives bacteria structural support. The bacterial cell wall is often a target for antibiotic treatment.
Structure and Function of a Typical Bacterial Cell with Diagram. The cell structure includes a complex membrane, membrane-bound protoplast, cell walls, cytoplasm, and nucleoids that contain genetic material. A bacterial cell’s outer layer or cell envelope comprises two components. A rigid cell wall. Underlying cytoplasmic or plasma membrane.
The Atlas of Bacterial & Archaeal Cell Structure, an open-access digital textbook, showcases microbial cells imaged by 3D electron microscopy