4.3 Signal Transduction (II)

• The environment is not static and organisms need to regulate pathways to respond to changes in the environment.
• The ability to respond to stimuli is a necessary characteristic of life and key for survival.
• Signal transduction may result in changes in gene expression and cell function.
• Signaling pathways can change the amount of a particular protein produced and can also alter gene expression.
• Changes in protein type and/or amount can result in a phenotype change.
• Apoptosis (cell death/suicide) can be a response of signal transduction.
• Signal Transduction can be used to respond to changes in the environment.
• Quorum sensing is a signal mechanism used by bacteria.
• In Quorum sensing bacteria releases signals to neighboring bacteria.
• Quorum Sensing is used to detect changes in population density so that food doesn’t run out and energy can be shared well enough (within a bacteria colony)
• Quorum Sensing allows bacteria to act as a group and respond to changes in the environment.