Question

After a signal binds to a signal receptor, the next step is transduction. Why is the signal transduction step necessary?
   
A. Transmission of the signal through multiple relay molecules before activating an effector is not efficient.
B. The more molecules that share the responsibility of passing the signal to activate the effector the more quickly and efficiently the message can spread.
C. The signal transduction pathway is not necessary since the signal can directly activate the effector.
D. The efficiency increases when less molecules share the responsibility of moving the signal from one molecule to the next to activate the effector.

Answer 1

Option B-The more molecules that share the responsibility of passing the signal to activate the effector the more quickly and efficiently the message can spread.

Signal transduction is the process of transmission of molecular signals from exterior of cell to interior of cell. Signals received by a cell should be effectively transmitted into the cell for an appropriate response

Each component (node) of the pathway is classified based the role it plays -For example-

a.first messengers-Ligands  

b.signal transducers - receptors

c.primary effectors is activated first

d.second messengers is activated by primary effector

e.secondary effectors activated by second messengers.

Depending on the efficiency of each component,the signal can be amplified (known as signal gain), so 1 signaling molecule can generate a response which involves millions of molecule