quorum sensing

Examples of quorum sensing in the following topics:

• Quorum Sensing

  • Quorum sensing is a system of stimulus and response correlated to population density.
  • Quorum sensing is a system of stimulus and response correlated to population density.
  • In similar fashion, some social insects use quorum sensing to determine where to nest.
  • Quorum sensing may be achieved by degrading the signalling molecule.
  • Some of the best-known examples of quorum sensing come from studies of bacteria.

• Signaling in Bacteria

  • Signaling in bacteria, known as quorum sensing, enables bacteria to monitor extracellular conditions, ensure sufficient amounts of nutrients are present, and avoid hazardous situations.
  • Because the number of cells present in the environment (the cell density) is the determining factor for signaling, bacterial signaling was named quorum sensing.
  • Quorum sensing uses autoinducers as signaling molecules.
  • Some species of bacteria that use quorum sensing form biofilms, which are complex colonies of bacteria (often containing several species) that exchange chemical signals to coordinate the release of toxins that attack the host.
  • Quorum sensing determines whether the bacteria should produce the luciferase enzyme.

• Elemental Boron

  • Some signaling compounds of boron which are used for bacterial cell to cell communication (known as "quorum sensing") have been discovered recently.
  • A known example of a boron-containing quorum sensing signaling molecule is Autoinducer-2 (AI-2).
  • AI-2 is used by many types of bacteria as a signaling molecule mediating quorum sensing.

• Bacterial Differentiation

  • These are survival strategies that affect the normal physiology of the bacteria in response to factors such as innate immune response, predator sensing, quorum sensing and antimicrobial signs.

• Starvation-Induced Fruiting Bodies

  • When starved of amino acids, myxobacteria, or slime bacteria, detect surrounding cells in a process known as quorum sensing.

• Biofilms

  • It is during this colonization that the cells are able to communicate via quorum sensing using such products as AHL.

• Two-Component Regulatory Systems

  • Two-component systems couple mechanism to allow organisms to sense and respond to changes in many different environmental conditions.
  • They typically consist of a membrane-bound histidine kinase that senses a specific environmental stimulus and a corresponding response regulator that mediates the cellular response.
  • Two-component signal transduction systems enable bacteria to sense, respond and adapt to a wide range of environments, stressors and growth conditions.
  • These pathways have been adapted to respond to a wide variety of stimuli, including nutrients, cellular redox state, changes in osmolarity, quorum signals, antibiotics, temperature, chemoattractants, pH and more.
  • The N-terminal domain of this protein forms part of the cytoplasmic region of the protein, which may be the sensor domain responsible for sensing turgor pressure.

• Committee Deliberation

  • Generally, discussion requires a quorum, usually half of the total number of representatives, before discussion can begin, although there are exceptions.
  • The Constitution specifies that a majority of members known as a quorum be present before doing business in each house.
  • However, the rules of each house assume that a quorum is present unless a quorum call demonstrates the contrary.
  • Since representatives and senators who are present rarely demand quorum calls, debate often continues despite the lack of a majority.

• The Mormons

  • After Smith's death, a succession crisis ensued, and a majority voted to accept the Quorum of the Twelve, led by Brigham Young, as the church's leading body.
  • Mormons have developed a strong sense of community that stems from their doctrine and history.

• References

  • Wesport: Quorum.