Presentation (7).pptx forestry...........

Forestry

1. BACTERIOPHAGE LYTIC AND LYSOGENIC CYCLE Understanding the viral life cycles in bacteria By: YAZHINI RAJ P.M.

2. BACTERIOPHAGE DEFINITION: A bacteriophage, or phage, is a type of virus that specifically infects and replicates within bacteria.

3. STRUCTURE Head (Capsid) : Contains the phage's genetic material (DNA or RNA). Tail: A sheath-like structure attached to the head. Acts as a condu c t for injecting genetic material into the host bacterium. Base Plate: Located at the end of the tail. Facilitates attachment to the bacterial surface. Tail Fibers : Extend from the base plate.Help in recognizing and binding to specific receptors on the bacterial cell wall.

4. LYTIC CYCLE Definition: A process where the phage replicates and lyses the host cell. Steps: Attachment
Penetration
Biosynthesis
Maturation
Lysis

5. STEPS: Attachment: Phage attaches to specific receptors on the bacterial surface. Penetration: Phage injects its DNA into the host cell. Biosynthesis: Phage DNA replicates and phage proteins are synthesized. Assembly : New phage particles are assembled. Release : Host cell bursts, releasing new phages.

6. LYSOGENIC CYCLE: Definition: A process where the phage DNA integrates into the host genome and replicates with it without killing the host. • Steps: Attachment Penetration Integration Prophage Replication Induction (trigger to enter lytic cycle)

7. STEPS: Attachment: Phage attaches to the bacterial cell. Penetration : Phage injects its DNA into the host. Integration: Phage DNA integrates into the bacterial chromosome, becoming a prophage . Prophage Replication: Prophage replicates along with the bacterial DNA. Induction: Under stress conditions, prophage can excise from the genome and enter the lytic cycle.

8. D/B LYTIC AND LYSOGENIC Lytic Cycle: Quick reproduction, host cell death. Lysogenic Cycle: Dormant phase, no immediate harm to host.