Bacteriophage Lambda Protein Functions

The video tutorial explains the lytic lysogenic switch of bacteriophage Lambda, a crucial concept in virology. It covers the molecular mechanisms involved, focusing on the roles of C1, C2, and C3 proteins in maintaining lysogeny, and the n and cro proteins in the lytic phase. The tutorial also describes the integration and excision processes of viral DNA with bacterial DNA, and how the concentration of proteins influences the switch between lysogenic and lytic cycles. The video concludes with a call to action for viewers to engage with the content.

What is the primary focus of the video lecture on bacteriophage Lambda?

• The structure of bacterial cells

• The immune response to viruses

• The lytic and lysogenic switch

• The lifecycle of human viruses

What is the role of the attP site in bacteriophage Lambda?

• It is the site of bacterial DNA replication

• It is the site of viral protein synthesis

• It is the site of viral DNA integration with bacterial DNA

• It is where the viral DNA is packaged

Which protein is crucial for maintaining lysogeny in bacteriophage Lambda?

• C1 protein

• Xis protein

• N protein

• Cro protein

Which promoters are involved in the production of C1 protein?

• OL and OR

• PRE and PRM

• PL and PR

• TL and TR

What is the role of C2 and C3 proteins in the lysogenic cycle?

• They stimulate the production of cro protein

• They integrate viral DNA into the host genome

• They act as anti-terminators

• They stimulate the production of C1 protein

What is the function of the n protein in the lytic cycle?

• It acts as an anti-terminator in transcription

• It integrates viral DNA into the host genome

• It initiates the lysogenic cycle

• It packages viral DNA

How does the cro protein influence the lytic cycle?

• It stimulates the production of C1 protein

• It integrates viral DNA into the host genome

• It acts as an anti-terminator

• It represses the action of C1 protein

What is the outcome when cro protein binds to the operator sites?

• Lysis is stimulated

• Lysis is inhibited

• C1 protein is produced

• Lysogeny is maintained

What happens when C1 protein concentration is high?

• The viral DNA is excised from the host genome

• The host cell is lysed

• The lysogenic cycle is maintained

• The lytic cycle is initiated

How does C1 protein auto-regulate its production?

• By integrating viral DNA into the host genome

• By stimulating n protein production

• By binding to operator sites and preventing further C1 production

• By inhibiting cro protein