I Like Plants, And You Should Too

As of late, while learning about photosynthesis, we have discovered the true reasons why plants are so helpful and are a necessary on our planet. Things such as, when photosynthesis is complete, plants emit the oxygen some of the oxygen that is created which helps us breathe. This is just one example of why plants and photosynthesis are so important. Photosynthesis consists of three energy conversions, absorption of light energy, conversion of light energy to chemical energy, and storage of chemical energy as sugar. Photosynthesis can also be broken down in to two processes, the light reaction and the dark reaction, also know as the Calvin cycle.

In the very beginning of the light reaction, the inputs are sunlight and water. This reaction takes place inside the thylakoid membrane. How this process works is the natural sunlight, or photons, are beamed down, and the energy those photons contain excite a small electron in the reaction center of PSII which then is transported down the ETC to PSI. By doing so, this creates enough energy for a hydrogen ion to pumped through the membrane and into the lumen. Once the electron has reached the end of the ETC it uses its energy to reduce NADP+ to NADPH. But how are these components replaced you might ask? This is where the water comes in to play. First the water splits, thus creating 2 hydrogen ions, 2 electrons, and one oxygen molecule. The way the electrons and H+'s get back to their respective positions is by going through the ATP synthase. The H+'s and electrons pump up the synthase which is powered by ADP which brings in another phosphate to create ATP, which leaves us where we started off. To summarize, the outputs of the light reaction are 1 NADPH, 1 ATP, and 1 oxygen molecule.

Two of the three outputs of the light reaction are going to be used to power the Calvin cycle, the NADPH and the ATP. Except, there is another input of the Calvin reaction that comes from the outside world, carbon dioxide. This reaction also takes place inside the thylakoid membrane. To start the cycle, the 3 carbons enter (one at a time). Since carbon dioxide is not usable energy, it has to be transformed. So once the carbon enters the cycle it is immediately met by 3 RuBP (one for each carbon), which is a 5-carbon molecule, to create a short-lived 3 6-carbon molecule. Since this 6 carbon molecule is still unstable, it is rearranged into 6 3-carbon molecules. This phase of the cycle is called carbon fixation. Next, 6 ATP and 6 NAPDH come in from the light reaction to rearrange the 6 3-carbon molecules into 6 PGAL's, which is a 3 carbon sugar. The 6 ATP is oxidized to 6 ADP and the 6 NADPH is oxidized to 6 NADP+ and 6 phosphates. From the 6 PGAL's, one of these leave to create 5 PGAL's. Then with the help of 3 ATP, the PGAL's are rearranged back into 3 RuBP, which is the beginning of the cycle. Finally, the outputs of the Calvin cycle are 1 PGAL, 9 ADP, and 6 NADP+.

These two processes are the components that make up photosynthesis. This doesn't always occur at the same speed every time. There are things that could tamper with the rate of photosynthesis. Two of those things I believe to be are sunlight, and heat. I think sunlight could be a factor because in order to start the light reaction you need sunlight, and if there isn't a sufficient amount, the rate could be a lot slower compared to if there a great deal of light. The reason why I think heat could also be a factor is because if there is a perfect amount of heat, then photosynthesis will run very smoothly. However, if there is too much heat, I think that it could possibly burn off necessary components of photosynthesis or can be too hot for the plant to handle. In conclusion, I believe that things such as sunlight and heat can be both extremely helpful to the rate of  photosynthesis, but also not as efficient if there are unbalanced amounts.