Bacteria: Characteristics

Bacteria: Characteristics

What are Bacteria?

Bacteria are prokaryotic organisms often consisting in one cell, typically 0.5-5 micrometers in length, with some exceptions. They are classified by various parameters, such as:

• Shape

• Interactions with other beings

• Temperature and condition of living

• Aerobic or Anaerobic

• Way of reproduction

• Way of feeding

Classification

Interactions with other beings

By shape

Way of feeding

• Chemotrophs
• Phototrophs

• Cocci (round)
• Bacilli (stick-shaped)
• Vibrio (comma-shaped)
• Spirilla (spiral-shaped)
• Spirochaetes (multiple spirals)

• Pathogens
• Mutualists (symbiotes)
• Commensals

Reproduction

Most of bacteria reproduce by binary fission, in which the cell grows in volume until two identical cells separate

Some bacteria reproduce by budding: in this process one bud forms at one end of the mother cell, it enlarges and then separates

Cell Structure

The Cell Membrane separates outsides from insidesCytoplasm is a solution of water and proteins where metabolic reactions take place Ribosomes are in cytoplasm and produce proteins A single circular chromosome of DNA stays in a cytoplasm region called nucleoid Cytoskeleton is a complex of proteins which give the cell its shape and are active in cellular division

External structures

Cell Wall protects the cellFlagella are needed for movement The Capsule is another protection outside of the wall Fimbriae or pilus can transfer genetic material and make attachment to a substrate possible

Sources

https://www.britannica.com/science/bacteria https://en.wikipedia.org/wiki/Bacteria Il nuovo invito alla biologia.blu: Organismi, cellule, genomi-Helena Curtis, N.Sue Barnes, Adriana Schnek, Alicia Massarini