There are three main types of bacteria, which come in various shapes. The cocci bacteria are spherical shaped. While they may occur as single cells, the cocci bacteria can also remain attached to others. There are different types of attached bacteria. These include Diplococci bacteria, Staphylococci bacteria, and Spirilla, Staphylocci bacteria occurs in clusters. Spirilla are negative bacteria that tend to be spiral, and the vibrio bacteria are comma-shaped. Bacteria are also placed into groups based on nutrition.
Autotrophic bacteria can synthesize their food from inorganic substances. There are two groups of autotrophic bacteria, which are photoautotrophs. They have colored pigment, which is green and purple. Their pigments are used to synthesize food. Chemosynthetic bacteria can synthesize food from given inorganic chemicals in the absence of sunlight. They don't require light energy to synthesize food.
Bacteria have five main characteristics. These characteristics are:
Unicellular: Bacteria are single-celled organisms. They spend most of their existence as independent organisms.
Lack of membrane-bound organelles: Bacteria are prokaryotes. This means that they lack a membrane-bound nucleus, specialized membrane-bound organelles like mitochondria and lysosomes. Bacteria also lack the plasma membrane.
Cell wall: The cell wall of bacteria is made up of peptidoglycan, which provides strength and prevents damage to the cell due to changes in the environment.
DNA: Bacteria possess a single circular chromosome. This genetic material is stored in an irregular shaped region called “nucleoid.”
Size shape: Bacteria are very small, and they can only be seen under the microscope. They also are identified by shapes such as cocci, bacilli, and spirilla shape.