Lecture 7 Flashcards
Week 3
In what ways do bacteria constantly monitor their surroundings?
Answer: Bacteria constantly monitor their surroundings for nutrients, stressors (e.g., antibiotics), and other cells.
Question: Why do bacteria make proteins according to conditions?
Answer: Bacteria make proteins according to conditions to avoid wasteful production and optimize resource utilization.
Question: What are the three levels of regulation controlling protein production and function in bacteria?
Answer: The three levels of regulation are transcriptional regulation (mRNA production), translational regulation (mRNA translation), and post-translational regulation (protein activity).
Question: What is transcriptional regulation in bacteria?
Answer: Transcriptional regulation in bacteria involves controlling the production of mRNA, influencing the synthesis of proteins.
Question: What is translational regulation, and how does it impact bacterial cells?
Answer: Translational regulation in bacteria refers to the control of mRNA translation into proteins. It plays a role in determining the rate of protein synthesis based on cellular conditions.
Question: How is post-translational regulation involved in controlling cellular functions in bacteria?
Answer: Post-translational regulation in bacteria involves modifying protein activity after translation, fine-tuning their functions to adapt to changing conditions.
Question: What is the significance of certain proteins for bacteria in the context of host colonization and infection?
Answer: Certain proteins are crucial for bacteria to colonize hosts and cause infections, but they are not needed outside the host environment.
Question: Why are certain genes not transcribed outside the host?
Answer: Certain genes are not transcribed outside the host because the proteins encoded by these genes are specifically required for interactions within the host environment.
Question: What are some factors through which bacteria can sense the host environment?
Answer: Bacteria sense the host environment through factors such as temperature (e.g., humans: 37 °C), nutrients (e.g., heme), and interactions with the host’s immune system.
Question: What is the role of temperature in bacterial sensing of the host?
Answer: Temperature, such as the human body temperature (37 °C), is a factor sensed by bacteria to determine their location within a host.
Question: What are the actions taken by bacteria in response to sensing the host environment?
Answer: In response to sensing the host environment, bacteria make proteins to attach to host cells, evade the immune system, and potentially kill host cells.
Question: Provide an example of a bacterial action related to pathogenesis.
Answer: An example of a bacterial action related to pathogenesis is the production of proteins that allow attachment to host cells, evasion of the immune system, and potentially causing harm to host cells.
What does RNA polymerase do in transcription?
transcribes DNA, making mRNA
What are the roles of the promoter and terminator?
Promoter: where to start
Terminator: where to stop
What is mRNA translated by?
ribosome
Question: What is a common feature of multiple genes that share a promoter in bacteria?
Answer: Multiple genes that share a promoter in bacteria often form operons, where a single promoter controls the transcription of multiple genes.
Question: Provide an example of a well-known operon and its characteristics.
Answer: An example is the lac operon. Transcription of the lac operon results in the production of polycistronic mRNA, and the genes within the operon typically have related functions.
Question: What is the outcome of the transcription of an operon in bacteria?
Answer: The transcription of an operon in bacteria produces polycistronic mRNA, allowing for the coordinated expression of multiple genes with related functions.
Question: What are the components of the core enzyme of RNA polymerase (RNAP)?
Answer: The core enzyme of RNA polymerase consists of five subunits.
Question: How do operons help bacteria respond to stimuli?
Answer: Operons in bacteria help coordinate the response to stimuli by allowing the simultaneous regulation of multiple genes involved in related functions.
Question: What is the significance of genes in operons having related functions?
Answer: Genes in operons having related functions enable bacteria to efficiently coordinate their response to environmental stimuli, as these genes often work together in specific biological pathways.
Question: What are the three main functions of RNA polymerase during transcription?
Answer: RNA polymerase performs three main functions during transcription: unwinding the DNA, synthesizing RNA de novo, and rewinding the DNA.
Question: What are Sigma (σ) factor proteins needed for in the process of transcription initiation?
Answer: Sigma (σ) factor proteins are needed for RNA polymerase (RNAP) to recognize promoters.
Question: Describe the initial step in transcription initiation.
Answer: The RNAP holoenzyme binds to the promoter region.