Unit 2 Cellular Communication

Question 1

Name 3 examples of positive feedback loops

Answer 1

Parturition

Blood coagulation cascade

opening of voltage-gated Na channels to initiate and propagate action potentials

Question 2

Neuroendocrine signaling is which type of signaling?

Answer 2

Endocrine signaling

Question 3

Neurotransmitter signaling is what type of signaling?

Answer 3

paracrine signaling

Question 4

What are autocoids and paracrine hormones? What is the main take-away for both?

Answer 4

local hormones

Both are:
produced locally

released in much smaller quantities than endocrine hormones

intended to act locally

metabolized locally

Question 5

Signal transductions are very selective/specific, and this is imparted by the cell-specific receptor. These interactions are mediated by the same weak non-covalent forces that mediate enzyme-substrate interactions. List these bonds in order of weakest to strongest

Answer 5

van der Waals < hydrophobic < hydrogen < ionic < covalent

Question 6

Multiple components of cell signaling pathways are often brought together on a certain type of protein. What is this protein and list one example/

Answer 6

Scaffolding protein, and the Ryanodine receptor (RyR) is a scaffolding protein in addition to being a calcium channel.

Question 7

What are the six steps involved in signaling sequences?

Answer 7

1. Recognition
2. transduction
3. transmission
4. modulation
5. response
6. termination of response

Question 8

List the 4 main receptor-based signal transducers:

Answer 8

transmembrane GPCRs

transmembrane ligand gated ion channels

transmembrane enzyme-linked receptors

soluble intracellular nuclear receptors

Question 9

What are the other 2 types of receptor-based signal transducers and give an example of each

Answer 9

1. extracellular target like dabigatran
2. adhesion molecules like eptifibatide