Module 4- cell communication Flashcards
Closed system
Tends towards equilibrium
Open system
Tends away from equilibrium
Steady state
Flow in = Flow out
Conformers
Body temp adapts to their environment
Regulators
remain at relatively the same body temp
Homeostasis
Organisms maintain a target set point for all their processes
Positive feedback
Feedback loop that continually moves father and farther from the homeostatic target
Negative feedback loop
The body will stop/start processes to return the system back to homeostasis
Sensor
Senses the level of the variable
set point
desired level of the environment
Comparator
Compares what the sensor has read with what the set point is. It will send out an error signal if the environment isn’t at the set point.
Effector
Returns the environment back to set point when needed
Autocrine
Cell sends signal to itself
Paracrine
Cell sends signal to nearby cells
Endocrine
Cell sends signals through the blood stream to far cells
Endocrine Glands
Ductless glands that stays in the body
Exocrine Gland
Signals go to a duct that usually leads to the GI tract or the surface of the organism
Polar hormones
can pass though the blood alone but need a membrane protein to enter the cell
Non-Polar hormones
Need protein carriers in the blood but can enter the cell on its own
Affinity
Strength of a bond
Membrane bound receptors
Receptors on the outside of the cell and cause a transduction pathway without the signal having to enter the cell
Cytoplasmic receptor
Receptor inside the cell which brings the signal into the nucleus
Open circulatory system
fluid- hemolymph
oxygen transfer- sinuses
pump- Heart
closed circulatory system
Fluid- blood
Oxygen transfer- capillaries
pump- heart
Early metazoans
- non directional bulk flow
- Fluid movement is generated by cilia and gut muscles
Plant hormones
- Peptides, small organic molecules
- local or distant
Animal hormons
- Peptides, small organic molecules, and proteins
- usually distant
germinates
plant seed starts to grow when environmental conditions are right
Gibberellins
Signal the synthesis of hydrolytic enzymes that breakdown stored
Phototropism
movement of a plant to the light source
Coleoptile
Sheet of plant cells that can sense light and move towards it
Phototropins
auxin triggers the production of this protein by moving into the plant cells in the shady side of the plant
Moves particles short distances
Apoplast and symplast
Moves particles long distances
Xylem- dead cells that move water, minerals, and hormones
Phloem- living cells that move the products of photosynthesis
Water potential
Reliant on osmotic potential and pressure potential
Dentrites
Main structure which receives the signal
Cell body
Can receive the signal, contains the organelles of the neuron
Axon Hillock
Location of summation
Axon
Carries the action potential to the next neuron
Chemical gradient
concentration gradient: high to low
Electrical gradient
gradient: positive attracts negative
leak channels
some ions can pass across the membrane
Ligand Gated Channels
open and close when a compound attaches to it
Voltage gated channel
open close based on the charge distribution
Permeability
Ability of an ion to move across the membrane
Depolarization
Membrane becomes more positive
Hyperpolarization
Membrane becomes more negative
Repolarization
Returns to resting potential (-70) after a disturbance
Synaptic cleft
space between the pre-synaptic cell and the post-synaptic cell
neurotransmitter
what is passed between neurons
EPSP
- Excitatory post synaptic potentials
- Depolarization
IPSP
- Inhibitory post synaptic potentials
- Hyperpolarization
Graded Potential
- minor change
- depolarized or hyperpolarized
- doesn’t meet threshold
Action Potential
- major change
- always depolarized
- threshold required
- steady state
Increase pressure
doesn’t increase action potential size but it does increas its frequency
