Prokaryote structure

• The capsule: A layer of material that surrounds the cell and protects it from the environment. It helps prokaryotes cling to each other and to various surfaces, and maintains the moisture of the cell.
• The cell wall: A rigid structure that surrounds the cell and provides support and protection. In most bacteria, it is made up of peptidoglycan, a polymer of linked sugars and polypeptides.
• Gram staining: A method used to differentiate between two types of bacterial cells based on their ability to retain crystal violet dye. Gram-positive bacteria have thicker walls than gram-negative bacteria and are more likely to stain purple with crystal violet dye.
• Flagella: Long, thin structures that extend outward from the cell surface and allow bacteria to move through liquids or along solid surfaces by rotating like propellers.
• Fimbriae: Short, hairlike appendages that project from the cell surface and serve as attachment sites for some pathogenic bacteria.
• Appendages: prokaryotic cells have protrusions that allow them to stick to surfaces, move around, or transfer DNA to others.
• Pili: longer appendages that can be used for attachment or movement.
• Most prokaryotes have a single circular chromosome.
• Prokaryotes store their genetic materials in a region called nucleoid.
• Plasmids: small rings of double-stranded extra-chromosomal DNA. They carry genes that are NOT essential to survival and are independently copied.