Question

Indicate whether each of the following descriptions applies to visual signal transduction (V), olfactory signal transduction (O), or both (B). Your answer would be a four-letter string composed of letters V, O, and B only, e.g. VOVV.

1. It involves cGMP as a second messenger.
2. A rise in cyclic mononucleotide concentration follows the arrival of the signal.
3. The signal is received by a G-protein-coupled receptor.
4. An incoming signal leads to membrane hyperpolarization.

Answer 1

The descriptions correspond to visual signal transduction, both visual and olfactory transductions, and visual transduction respectively; the answer is VBVB.

Step-by-step explanation:

To determine whether each description applies to visual signal transduction (V), olfactory signal transduction (O), or both (B), we analyze each statement:

cGMP as a second messenger: This is associated with visual signal transduction where cGMP levels modulate the opening of ion channels in photoreceptor cells in the retina (V).

A rise in cyclic mononucleotide concentration follows the arrival of the signal: This can be true for both visual (cGMP) and olfactory (cAMP) signal transduction as the concentration of these cyclic mononucleotides increases following signal reception (B).

G-protein-coupled receptors (GPCRs): Both olfactory and visual signals are received by these receptors, signaling the presence of either photons or odorant molecules to the cell (B).

An incoming signal leads to membrane hyperpolarization: In visual transduction, the arrival of photons ultimately leads to the hyperpolarization of photoreceptor cell membranes, which is not typical in olfactory transduction (V).

Thus, the answer is VBVB, indicating each corresponding property applies to visual, both, visual, and visual transduction respectively.