AP Bio Chapter 45 Part 1 Flashcards
What occurs in reception
Ligand (hormone or environmental stimulus) binds to receptor on cell membrane
What are the three phases of signal reception
Reception, transduction, response
What happens in transduction
In the cytoplasm, where the relay proteins and second messengers are
What is the response
The activation of cellular responses
In local signaling what happens in paracrine signaling
Local regulator diffuses through extra cellular fluid from secreting cell (secretory vesicles) and the target cell picks up the message
In local signaling what happens in synaptic signaling
Electric signal around nerve cells triggers release of neurotransmitter, neurotransmitter diffuses across synapse, target cell is simulates
Signals can move through _____________________________
Cellular junctions (gap junctions, plasmodesmata, cell-cell recognition)
What handles long distance signals in animals
The nervous and endocrine system. Occurs in blood vessels
What else could serve as a signal
Pretty much every other chemical or energy source, but most are biologically created molecules
How are signals received
Different chemistry, different reception, different receptors
What are some of the types of signaling pathways
G linked protein reception, tyrosine kinesis, ligand gated ion channels
Ligand gated ion channels
The incoming ions trigger a response. Ligand binds, door opens, falls off, door closed
G protein linked reception
Ligand binds to G protein, activates protein by adding phosphate, protein activates a cellular response (could lead to affinity for an enzyme e.g.) phosphate falls off, G protein is deactivated
G protein
Hydrophilic?
Proteins activated by the transfer of a phosphate from a molecule of GTP. can be stuck to membrane or diffusable
Tyrosine kinesis
2 kinase must bond, stick to one another to form a dimer, gets phosphorylated, now active as long as bound to receptor molecules
Different (or same) receptors can have
Different cellular responses
What happens as a result of epinephrine hitting the beta cell in the liver
It causes glycogen to be broken down into glucose in the bloodstream in the liver, when epinephrine hits beta receptor vessel dilates in skeletal muscle
Second messengers
Internal signaling molecules released due to external (first) signals. Trigger sub-response pathways
What does cyclic AMP affect
Second messenger, metabolism
How can same receptors have different responses
Different transduction and response of signal reception
Cells ______________ a ________________ as one of the outcomes of signal reception
Amplify a response
Negative feedback
End product stops production, once there is enough.
Positive feedback
One you start making the product, it wants to keep producing until it can’t
Contraction and lactation are examples of
Positive feedback
Reception
In cellular communication, the first step of the signaling pathway in which a signaling molecule is detected by a receptor molecule on or in the cell.
Transduction
In cellular communication, the conversion of a signal from outside the cell to a form that can bring about a specific cellular response. (Signal transduction)
Response
In cellular communication, the change in a specific cellular activity brought about by a transduced signal from outside the cell.
Ligand
Hormone or environmental stimulus
A molecule that binds specifically to another molecules, usually a large one.
