Communication amongst Cell Plants
1. Growth and Development
3. Repair Damage
Communication amongst Cell Animals
1. Growth and Development
3. Protect and repair
4. Movement and Behavior
Cell similarities plant and animals
Use similar mechanisms (how)
Specialize via different types of equipment (what)
All living cells release signals to communicate to other cells
Changes in a cell's membrane potential (K and Na)
Specialized form of communication (neurons and muscles in animals)
Rapid, fine-tuned changes
Molecules secreted from a cell (exocytosis)
Slower, more long term changes
Most common form of communication
form direct cytoplasmic connections between adjacent cells
require interaction between membrane molecules on two cells
act on the same cell that secreted them
are secreted by one cell and diffuse to adjacent cells
Gap junctions for plants
are secreted by endocrine glands or cells into the blood. Only target cells with receptors for the hormone will respond to the signal
are chemicals secreted by neurons that diffuse across a small gap to the target cells. Neurons use electrical signals as well
are chemicals release by neurons into the blood for action at distant targets
neighboring cells communicate to control a response within the same tissue
The tissue that issues the signal is outside/long distance from the one that carries out the response
Endocrine System Human Model
Oversees long term, slow changes in body
What are the actions at target cell?
Adjusting enzyme activity
Influencing permeability and transport
Increasing/decreasing gene expression
What secrete hormones into the bloodstream?
What are the 3 classes of hormones
2. Peptides and proteins
What amines derived from?
What are steroids derived from?
How are protein and peptide hormones produced?
1. Made in advance
2. Packaged into secretory vesicles as inactive prohormone
3. Release via exocytosis
Blood transport of protein and peptide hormones?
Mostly hydrophilic, freely dissolve in plasma
How are Steroids produced?
1. Produced as needed
2. Cannot be stored/stockpiled easily
Blood transport of Steroids?
Hydrophobic, not readily dissolved in plasma
How are Steroids transported?
Transported via protein carriers (shuttles) such as albumin and corticosteroid-binding globin
Amine type hormones
Derived mostly from tyrosine and tyrptophan which is melatonin
behave like peptides
i.e. epinephrine, norepi, and dopamine
behave like steroids
i.e. T3 and T4
Lipophillic signal molecules
diffuse through the cell membrane and bind to cytosolic or nuclear receptors
bind to receptors on surface of cell membrane
Hormones are cleared by?
Liver and kidneys
time it takes to clear 50% hormone from blood
If it's at the target cell, it's cleared via
Endocytosis and enzyme degradation
Stimulates muscle contraction in mammary glands and uterus
Stimulates reabsorption of water in kidneys
Oxytocin and ADH
1. Made in the hypothlamus
2. Transported to post. Pituitary
3. Stored in post. Pituitary until release
Hypothalamus ==> Ant. Pituitary
1. Hypophysiotropic hormones
2. Hypothalmus release hormones into blood
3. Received by ant. Pit
4. Hormone release is increased/decreased from ant. Pit.
Growth hormone (somatotropin)
Stimulates increased metabolism and growth
Stimulate release of hormones by liver
Follicle-stimulating hormone and Luteinizing hormone (FSH and LH)
Stimulate gonads to release testosterone and progesterone