The three primary mechanisms by which molecules move across the cell membrane are : - Passive transport, the movement of molecules that does not require energy - Diffusion, when molecule move from higher concentration to lower concentration - Osmosis, when molecule move to higher concentration
They provide energy because photosynthesis makes sugar (glucose) which results into ATP(energy). In CR (cellular resp), oxygen is broken down during the process of photosynthesis and is used in CR to make water with hydrogen bonds.
