This document summarizes the structure of prokaryotic or bacterial cells. It describes that bacterial cells are smaller and simpler than eukaryotic cells. The main parts of a bacterial cell include the cell envelope consisting of a capsule, cell wall, and cell membrane. The cytoplasm contains ribosomes, a nucleoid which holds the single chromosome, and sometimes plasmids. Appendages like flagella, pili, and fimbriae are also described, with flagella aiding locomotion and pili and fimbriae helping attachment to surfaces.

1. Practical Biology
By
Hawraa kareem
Lecture 3

3. Prokaryote cells are smaller and simpler. Commonly
known as bacteria

4. Structure of Bacterial Cell
1. Cell envelope: Capsule ,cell wall, cell membrane
2. Cytoplasm : ribosomes, nucleoid, chromosome.
3. Appendages : flagella, pili , fimbriae

5. 1. Cell Envelope
A. Capsule :
 It is the outermost layer of the cell envelope
 Protection and Attachment

6. B. Cell wall:
It is rigid solid covering which provides shape and structural support
to the cell.

7. C. Cell Membrane
•It is selectively permeable covering of the cytoplasm
•It is made of a phospholipid bilayer with proteins

8. 2. Cytoplasm
 Gel-like matrix of water, enzymes, nutrient.
 Cytoplasm contain:-
1) Nucleoid:
Region of cytoplasm where (DNA) is located.
2) Plasmid
Small extra piece of chromosome/genetic material.
3) Ribosomes
The site of protein production within the cell

9. 3. Appendages
1- Flagella :
Flagella are the organelles of locomotion for most of the
bacteria
2- Fimbriae
Fimbriae are small hair-like fibers Involved
in attaching bacteria to solid surfaces.
3- Pili :
 pili are longer, fewer and thicker
tubular outgrowths
 pili are made up of protein pilin.