Which of the following molecules acts as the primary signaling molecule in bacterial quorum sensing processes?

• A. Neurotransmitters
• B. Steroid hormones
• C. Insulin
• D. Autoinducers

Answer: (D)

Verified step by step guidance

1. Understand the concept of quorum sensing: Quorum sensing is a communication mechanism used by bacteria to coordinate behavior based on population density. It involves the production, release, and detection of signaling molecules.
2. Identify the role of signaling molecules in quorum sensing: These molecules, known as autoinducers, are produced by bacteria and accumulate in the environment as the bacterial population grows. When a threshold concentration is reached, they trigger changes in gene expression.
3. Compare autoinducers to other signaling molecules: Neurotransmitters, steroid hormones, and insulin are signaling molecules in multicellular organisms, but they are not involved in bacterial quorum sensing. Autoinducers are specific to bacterial communication.
4. Recognize the specificity of autoinducers: Autoinducers are unique to quorum sensing and are chemically distinct from other signaling molecules. They allow bacteria to regulate processes such as biofilm formation, virulence, and bioluminescence.
5. Conclude that autoinducers are the correct answer: Based on the explanation above, autoinducers are the primary signaling molecules in bacterial quorum sensing processes.