Visual system; photoreceptors

The interesting thing is how light energy is turned into electrical energy using a single cell. It is amazing how the photoreceptors accumulate and work together to create a detailed 'picture' of the world.

the power of transduction. this is a useful mechanism that will be really useful in producing electricity. Where light shined on a protein, changes the electrical potential of a cell, making it more positive or negative. Imagine if we could make a single cell, like in the thick ascending limb cells, where there is a concentration gradient set up with the proteins, allowing a one-way movement of ions. However, this requires a high concentration of the ion outside the cell otherwise it wouldn't work... but an interesting thought!

identifying the citizens of a cell

Is there a way of identifying all the proteins active in a cell and how they interact with one another?

What is the perfect method of understanding intracellular protein-to-protein interaction? The best method so far lies in knock-outs/in experimentation, where mutation is induced. However, this method takes a longer time and even though the exact mechanism of interactions unknown.

What we need is a way of taking one cell and identifying the proteins involved, then tagging the proteins and observing how they interact with one another. The important question is HOW can this  be done??