Bacteria have a variety of structures both external and internal to their cell wall. Externally, they may have flagella for locomotion, pili or fimbriae, and a capsule. Internally, they contain a plasma membrane, mesosomes, ribosomes, a nucleoid or bacterial chromosome containing genetic material, and plasmids which can provide functions like antibiotic resistance. Bacteria sizes vary greatly from 0.5 to 100 micrometers in length. They have a cell wall composed of peptidoglycan which provides shape and protection to the cell.

1. STRUCTURE OF BACTERIA
Dr. V. RAMESH
Assistant Professor & Head In-Charge,
Department of Botany,
Vivekananda College,
Tiruvedakam West – 625 234
Madurai

2. BACTERIADiscovered by Antony van Leuwenhoek
Coined by Ehrenberg

3. Size varies from 0.5 µ – 3 µ
Smallest Pelagibacter ubique (length of 0.37–0.89 µm) Largest is
Thiomargarita namibiensis 0.1–0.3 mm (100–300 μm)
Primitive
Incipient Nucleus Present
Plasmid present
Cell wall – Peptidoglycon
Categories - Bacteria, Cyannobacteria (BGA), Archebacteria
Absorptive mode of Nutritoin
Reproduction is Binary fission
70 S Ribosomes
Locomotion by Flagella
GENERAL CHARACTICS

5. Structure of Bacterial Cell

6. COMPONENTS OF BACTERIA

7. COMPONENTS OF BACTERIA
External to the cell wall Internal to the cell wall
Flagella
Pilli or Fimbriae
Capsule
 Plasma memrane
Mesosomes
Ribosomes
Chromosome
Plasmids
 Inclusions
Vacuoles
Capsule
Cell wall
Plasma Membrane

8. Capsule or glycocalyx
Function

9. CELL WALL

10. FUNCTION OF CELL WALL

11. PLASMA MEMBRANE
Function

12. MESOSOME

14. NUCLEOID OR BACTERIAL CHROMOSOME

15. PLASMIDS
Functions
Antibiotic resistance
Resistance to heavy metals
Resistance to UV Light
Ability of adherence of epithelial cells

17. FLAGELLA
Types
Atrichous – Absence of Flagellum
Function - Locomotion

19. PILI or FIMBRIAE
Types
Function