Lytic and Lysogenic Cycles of Bacteriophage Lambda

These flashcards cover key concepts related to the lytic and lysogenic cycles of the bacteriophage lambda, focusing on the stages, processes, and terminology involved.

What are the main stages of the lytic cycle for bacteriophage lambda?

The main stages include attachment, penetration, phage DNA replication, phage assembly, and cell lysis.

What occurs during the attachment stage of the lytic cycle?

The bacteriophage lambda attaches to receptors on an E. coli cell while the capsid remains outside the bacterial cell.

What happens during penetration in the lytic cycle?

The bacteriophage lambda injects its DNA into the E. coli cell.

What is the role of endonuclease enzymes during phage DNA replication?

Endonuclease enzymes degrade the E. coli chromosomes, allowing the bacteriophage to hijack the cell’s transcription and translation processes.

What happens during phage assembly in the lytic cycle?

The metabolism of the E. coli cell is used to assemble phage DNA and capsids into new bacteriophages.

What occurs during cell lysis in the lytic cycle?

The E. coli cell bursts open, releasing newly created phage viruses.

What is the difference between the lytic and lysogenic cycles?

In the lytic cycle, the virus immediately replicates and lysis occurs, while in the lysogenic cycle, the virus integrates its DNA into the host DNA and can remain dormant.

What happens during the attachment stage of the lysogenic cycle?

The bacteriophage lambda attaches to receptors on an E. coli cell, similar to the lytic cycle.

What is a prophage in the lysogenic cycle?

Prophage is the viral DNA that is incorporated into the bacterial chromosome.

What happens when an E. coli lysogen reproduces?

The lambda bacteriophage DNA is replicated along with the bacterial chromosome, and all offspring will contain the viral DNA.

What triggers induction in the lysogenic cycle?

An E. coli lysogen is triggered to enter the lytic cycle, causing the prophage to be excised from the bacterial chromosome.

What is the final outcome of the lysogenic cycle?

Phage DNA replication begins, leading to lysis and the release of many new copies of the lambda bacteriophage.