Transduction Pathways

Question 1

What are the principles of Cell Signaling?

Answer 1

Signal Reception (signaling molecules), Transduction, response (receptors)

Question 2

How do cells formulate a response?

Answer 2

Cells detect stimuli in their extracellular environment for which they have an appropriate receptor

Question 3

How does Paramecium display the effects of stimuli detection?

Answer 3

Ciliary beating changes due to stimuli detected.

Bacteria->Positive Chemotaxis->Negative chemotaxis->Positive photoaxis->Light

Question 4

What is Signal Transduction?

Answer 4

The process of converting an extracellular signal into an intracellular signal in a target cell

Question 5

What is the role of intracelluar signal?

Answer 5

Initiates a series of INTRACELLULAR REACTIONS that regulate metabolism, movement, proliferation, survival, and differentiation of the target cell

Question 6

What are the Six steps of Cell Signalling?

Answer 6

(1)SYNTHESIS: done by the signaling molecule in the signalling cell
(2) RELEASE of the signaling molecule by the signaling cell
(3)TRANSPORT of the signalling molecule to the target cell
(4)DETECTION of the signal by a specific receptor protein
(5)a CHANGE in cellular metabolism and function
(6) REMOVAL of the signalling molecule which terminates the cellular response

Question 7

What are the five classes of Cell signaling?

Answer 7

1. Endocrine signaling
   2.Paracrine Signaling
   3.Autocrine Signaling
   4.Neuronal Signaling
   5.Direct (contact-dependent) cell-cell signalling (e.g. Cell adhesion)

Question 8

What classes of cell signalling are SHORT DISTANCE?

Answer 8

-Direct signalling
-autocrine and paracrine signalling

Question 9

What classes of cell signalling are classified as LONG DISTANCE?

Answer 9

-endocrine signalling
-neural signalling

Question 10

What are the types of chemical messengers?

Answer 10

1. Peptides (oxytocin)
2. Steroids (estrogen)
   3.Amines (norepinephrine)
   4.Eicosanoids(prostaglandins)
   5.Purines (adenosine)
   6.Gases (nitric oxide,NO)

Question 11

What characteristics of chemical messengers affects signaling mechanisms?

Answer 11

Hydrophilic vs Hydrophobic

Question 12

What are the 6 characteristics of Peptides/Proteins

Answer 12

-2-200 amino acids long
-synthesized on the ROUGH ER
•often as larger preprohormones
-stored in vesicles
•prohormones
-secreted by EXOCYTOSIS
-hydrophilic (insulin)
•soluble in aqueous solutions
•travel to target cell dissolved in extracellular fluid
-bind to transmembrane receptors
•signal transduction