Eubacteria Flashcards

Study Notes

Eubacteria is a kingdom encompassing all prokaryotes excluding archaebacteria.
They play essential roles in fermentation, exemplified by the creation of yogurt and vinegar.

Peptidoglycan: A compound forming rigid bacterial cell walls, composed of polypeptides and modified sugars.
Nucleoid: A nucleus-like region containing the bacterium's DNA.
Ribosomes: Cytoplasmic particles involved in protein synthesis by translating genetic messages into proteins.
Cell Membrane: Also known as the plasma membrane; it is semi-permeable and regulates nutrient and waste transport.
Capsule: Protective covering that aids in food storage and waste removal.
Cell Wall: A protective, rigid structure made of peptidoglycan that maintains cell shape and withstands pressure.

Plasmid: Small DNA rings carrying accessory genes, independent of chromosomal DNA.
Pili: Hair-like structures facilitating interaction between Eubacteria.
Flagella: Long, whip-like structures enabling locomotion; movement speeds can reach about 50 µm/s.

Size: Generally microscopic, ranging from 0.5 µm to 5 µm.
Shapes: Common forms include cocci (spherical), bacilli (rod-shaped), and spiral (twisted/comma-shaped).
DNA Structure: Each Eubacterium contains a single chromosome in the nucleoid, with additional plasmid DNA for replication.

Movement: Many Eubacteria use one or multiple flagella, which can be positioned variously on the cell body.
Reproduction: Eubacteria reproduce via binary fission (asexual) and conjugation (sexual).
- In binary fission, cells divide into two.
- During conjugation, two cells connect through pili, forming a mating bridge that transfers plasmid DNA.

Eubacteria and legumes, especially the Rhizobium family, collaborate by fixing nitrogen in soil, which is vital for plant survival.
Certain Eubacteria, such as E. coli, can cause foodborne illnesses, particularly from contaminated uncooked meat.