Response to Stimuli

Response to Stimuli

Experimental method
Animal
Stimulus Response Model
1. Stimulus
  1. Sensory Receptors
    1. Affectors
    2. Thermoreceptros
  2. Eternal and Internal environmental factors
    1. Physical and Chemical
  3. Detection
2. Response
3. Receptors
4. Negative feedback (reduces stimulus back to acceptable limits)
  1. as opposed to positive feedback which increases stimuli until task is comlete (unstable-doesn't add homeostaisi
Plant
1. Hormone/growth regulators
  1. Types of hormones
    1. Auxin
  2. Transport
    1. Vascular System
      1. Xylem
      2. Phloem
    2. Through the air
      1. Ethylene
    3. Diffusion through the cell
2. Trophism
  1. Growth Response
  2. Phototropism
    1. Light
    2. Apical tip
      1. Zone of elongation
        Meristem
  3. Geootropism
    1. Gravity
    2. Accumulation of auxin
      1. Uneven growth
    3. Low concentrations auxin inhibitor
      1. Abscisic acid
  4. Thigmotropism
    1. Physical contact
    2. Uneven auxin distribution causes bending
3. Temperature response
  1. Enzymes affected
  2. Dormancy
  3. Vernalisation
Bacteria
Nervous
1. Signalling Molecules
Hormonal
1. Signalling Molecules
Signal Tranduction
1. Lipid soluble
  1. Through the membrane
    1. Binds with an internal receptor
      1. Forms a hormone-receptor complex
      2. Can activate or suppress the production of a protein
        Gene activation
        Transcription and translation for genes with codes for proteins
    2. Simple diffusion
  2. Examples
    1. Steroids
      1. Estrogen
      2. Testosterone
    2. Thyroid
      1. Derived form Thyroxine
  3. In blood stream
    1. Carrier Protein
      1. Allows the non polar hormone to dissolve in polar blood plasma
  4. Effects
    1. Slower
      1. Completion of proteins takes a very long time
    2. Long lasting
      1. Proteins like enzymes can be reused
      2. Regulates long term development
2. Water soluble
  1. Cannot pass through the membrane
3. What is it?
  1. Cascade of processes
Signalling molecules
Apoptosis
1. Controlled process
2. Cell Shrinkage
  1. Blebbing
    1. Loses it's shape
    2. Bubbles hanging off the cell
    3. Nuclear Fragmentation
      1. Chromatin Condensation
        Chromosomal DNA fragmentation
        After death engulfed by phagocytic cell

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	Criado por Minoshka Bocarro aproximadamente 8 anos atrás