Detecting+and+Responding+to+signals

=__BIG IDEA__= =2. Organisms have mechanisms by which they detect and respond to signals internally and externally.=

=Key Knowledge for this big idea:= =Areas to cover:=
 * detecting external and internal signals, converting signals into useful information, responding to them appropriately
 * signalling molecules: neurotransmitters, animal hormones, pheromones and plant growth regulators
 * signal transduction by membrane receptors
 * internal communication systems
 * 1) Receptors
 * 2) signal transduction
 * 3) co-ordinating responses
 * 4) sensing and responding in plants



Receptors
Receptors detect signals. They are specialised molecules capable of receiving and responding to specific stimuli such as signalling molecules or other environmental stimuli

An example of receptors working in our body:



== || what is signal transduction? The cascade of processes by which an extracellular signal (typically a hormone or neurotransmitter) interacts with a receptor at the cell surface, causing a change in the level of a second messenger (for example calcium or cyclic AMP) and ultimately effects a change in the cells functioning (for example: triggering glucose uptake or initiating cell division). Can also be applied to sensory signal transduction, for example of light at photoreceptors. definition taken from :http://www.biology-online.org/dictionary/Signal_transduction || ==

co-ordinating responses
Biozone 2009 Year 12 Biology Student workbook - work through pages 93,99,100,101,108

Biozone 2009 Year 12 Biology Student workbook - work through pages 88-92

ACTIVITY: Choose one of the following neurological diseases: Research and answer the following questions: Present your research to the class in the form of an oral or multimedia presentation or a poster.
 * Multiple Sclerosis
 * Alzheimer’s Disease
 * Motor Neuron Disease
 * Parkinson’s Disease
 * 1) What happens to the neurons in this disease?
 * 2) How does this affect their ability to function efficiently?
 * 3) What current technologies are effective in treating/managing this disease?
 * 4) Outline research that may lead to more effective treatment in the future.


 * Key Knowledge (Table of Contents)**