cell signaling

Question 1

selectivity in cell signalling

Answer 1

• molecular complementarity between the signal (ligand) and the receptor
• specific target cells - only certain cell types express certain receptors, transduction proteins, and/or effector proteins
• target cells produce specific responses (usually based on cell type)

Question 2

cooperativity in cell signaling

Answer 2

• ligand binding to signaling protein/receptor increases affinity for further binding (increased response)
• typically for things with multiple subunits

Question 3

amplification in cell signaling

Answer 3

• signalling cascades can produce the amplification of a signal many orders of magnitude in msecs
• live viral memes

Question 4

modularity

Answer 4

• allows a cell to use a set of proteins in different ways to create complexes with different functions or cellular locations
• different combos of protein monomers can form dur to particular ligand binding and/or due to modifications of interaction domains

Question 5

signal integration

Answer 5

• multiple inputs through different receptors produce a unified (integrated) signal that leads to the proper maintenance of homeostasis
• complex cross-talk determines final outcome

Question 6

autocrine cell signaling

Answer 6

cells release molecule that affects themselves and nearby cells

Question 7

paracrine signaling

Answer 7

affects nearby cells

Question 8

endocrine signaling

Answer 8

• travels through bloodstream
• sends signal to distant cells

Question 9

what are three possible ways that a signaling pathway can be terminated?

Answer 9

1. ligand can release
2. pathway molecules can be shut down
   
   • ex: protein gets unphosphorylated
3. negative feedback can stop it

Question 10

what are 3 possible reasons that the same type of signal would cause a different response in different cell types

Answer 10

1. certain cells may not have the right receptor
2. cascade intermediates can differ
3. can produce different responses at the end of the pathway