Biological Olfaction - The Electronic Nose Artificial Olfaction Technology - page 81

3.6.1 Characteristics of Signal Transduction Events

Specificity: Signal molecule fits binding site on its complementary receptor; while
other signals do not fit. Figure 3.12 illustrates the receptor binding of signal
molecules.
Amplification: when enzymes activate enzymes, the number of affected mol-
ecules increases geometrically in an enzyme cascade. Figure 3.13 illustrate

amplification process of enzymes.
Adaptation: Receptor activation triggers a feedback circuit that shuts off the
receptors or removes it from the cell surface. This process is illustrated in
Fig. 3.14 .
Integration: when two signal have opposite effects on a metabolic character-
istic such as the concentration of a second messenger X, or the membrane potential
V m , the regulatory outcome results from the integrated input from both receptors.
Signal integration is shown in Fig. 3.15 .

Fig. 3.12 Illustration of receptor binding

Fig. 3.13 Enzyme amplification