The flowchart will be as follows:
Plant shoot is exposed on one side, but not the other side. Then, phototropins in the shoot tip will absorb the blue light. Auxin, a plant hormone, will be released asymmetrically at the tip of the shoot. The auxin released from the stimulus will bind to an auxin receptor and activate the proton pump (H+ pump) activity in the cell membrane making the cell wall more acidic. In an acidic environment, a group of proteins called expansins are activated functioning to connect cellulose microfibrils to each other. Water will then enter the cell and increase cell turgor and subsequently expand the cell leading ultimately to the unequal growth of the plant shoot.
