Increasing substrate concentration also increases the rate of reaction to a certain point. Once all of the enzymes have bound, any substrate increase will have no effect on the rate of reaction, as the available enzymes will be saturated and working at their maximum rate.
2) The concentration of O2 will increase inside the cell.
The cell will want to reach equilibrium, meaning that there should be an equal number of oxygen inside and outside the cell. In the picture, more oxygen is shown outside the cell than inside so oxygen will flow into the cell until it has reached equilibrium. Therefore, the concentration of O2 will increase in the cell.
Hope this helps!!
