__________ is the process by which a message recieved by a cell is translated into a specific action within the cell.
Signal Transduction Pathway / cell signaling
What are two types of chemicals called local regulators?
1. Neurotransmitter
2. Hormone
Hormone signaling is also known as _______________.
Endocrine Signaling
In animals, hormones are released into the _____________ for transport through the body.
Circulatory System
What are the three stages of cell signaling? Define in your own words.
1. Reception - When a target cell recieves a signal (detected when it binds to a cellular protein on the surface)
2. Transduction - When the signal molecule converts the receptor protein to bring about a specific response
3. Response - The converted signal triggers a specific response in the cell
What are some examples of cell responses to a signal?
- catalysis by an enzyme
- rearrangement of the cyoskeleton
- activation of specific genes in nucleus
A _______ is a small molecule that binds to a larger one.
Ligand
What on the cell's surface recognizes a signal molecule?
specific sites on receptor proteins embedded in cell's plasma membrane
What are the three types of membrane receptors?
1. G-Protein-Linked Receptor
2. Tyrosine-Kinase Receptor
3. Ion-Channel Receptor
When GDP is bound to the receptor, is the G protein active or inactive?
Inactive
What does an activated G protein do?
An activated G protein binds to another protein (usually an enzyme) and alters its activity
In what are G-protein receptor systems often involved?
- embryonic developement
- sensory reception
- human diseases - bacterial infection
What type of cellular activity does the receptor tyrosine kinase do?
enzymativ activity
In what cellular or bodily process are tyrosine kinase receptors often involved?
Helps the cell regulate and coordinate cell reproduction to stimulate cells to grow and reproduce.
What is the function of ion channel receptors?
allow or block the flow of specific ions
What property must a chemical messenger have in order to reach an intracellular receptor?
Hydophobic enough the cross the phospholipid interioir of the membrane
Give an example of a chemical messenger that crosses the plasma membrane.
- Steroid hormones
- Thyroid hormones
- Nitric Oxide (NO)
What action inside of the cell do steroids usually cause?
The hormone binds to the receptor protein, activating it. The active receptor protein then eneters the nucleus and turns on specific genes that control male characteristics.
Why do different cells have different responses to the same cell signal?