#Question id: 40461
#Applied Microbiology
In the E. coli chemotaxis pathway, which of the following events directly leads to "tumbling" behavior?
#Question id: 40462
#Applied Microbiology
Consider the following statements regarding the Adaptation phase of chemotaxis:
Statement I: Adaptation allows bacteria to reset their sensitivity to attractant concentrations, enabling them to detect changes over a wide range.
Statement II: The protein CheB acts as a methylesterase that removes methyl groups from the MCP receptors, while CheR acts as a methyltransferase.
Which of the above statements is/are correct?
#Question id: 40463
#Applied Microbiology
Assertion (A): In the presence of a high concentration of an attractant, the frequency of bacterial tumbling decreases (longer runs).
Reason (R): Attractant binding causes a conformational change in the receptor that inhibits CheA kinase activity, leading to reduced levels of CheY-P.
#Question id: 40464
#Applied Microbiology
Match the Che protein in Column I with its primary function in Column II.
| Column I (Protein) | Column II (Function) |
| A. CheA | 1. Response regulator that controls motor switch |
| B. CheY | 2. Phosphatase that dephosphorylates CheY |
| C. CheZ | 3. Sensor Histidine Kinase |
| D. CheR | 4. Constitutive Methyltransferase |
#Question id: 40465
#Applied Microbiology
During the Penetration phase of a typical T-even bacteriophage infection, which of the following events occurs?
#Question id: 40466
#Applied Microbiology
Consider the following statements regarding the Biosynthesis (Synthesis) phase:
Statement I: "Early proteins" synthesized during viral infection are typically enzymes needed for viral DNA replication and to halt host cell metabolism
Statement II: "Late proteins" include structural components like capsid proteins and tail fibers, which are synthesized after the viral genome has been replicated.
Which of the above statements is/are correct?