This is response post to classmate William
- Briefly explain the light-dependent reactions of photosynthesis: where does this take place, what are the reactants and what is produced?
In the thylakoid membranes, ATP and NADPH are described as a conversion of solar energy to chemical energy. During this conversion, electrons are produced by splitting the water molecules (reactants), which then releases the excess atoms, oxygen (by-product). (Simon, Dickey, and Reece, 2013, Campbell Essential Biology 7th edition, pg.109- 110) Photosynthesis occurs when light energy hits the chlorophyll in green plants. Using the energy from light, plants split water to release oxygen and add the hydrogen atoms to carbon dioxide to make the carbohydrate glucose. In the light dependent reaction two electrons become excited by light energy. A water molecules is split to replace the electrons in chlorophyll. Oxygen gas is produced. The electrons from chlorophyll pass through two electron transport chains. The energy from the first electron transport chain is used to produce ATP. At the end of the second electron transport chain the coenzyme NADP accepts the hydrogen that remained from water
2. Briefly explain the light-independent reactions of photosynthesis: where does this take place, what are the reactants and what is produced? How do plants store excess products from these reactions?
The Calvin Cycle (light-independent reactions) of photosynthesis, is the location to produce sugar/ from carbon dioxide. In this process, we see how ATP and NADPH perform their tasks in the process of photosynthesis. Light reactions produce ATP, which then provides energy for sugar synthesis. In contrast, the NADPH contributes high-energy electrons to acquire a combination of glucose from carbon dioxide. Ultimately the Calvin Cycle relies on the light reactions to be able to perform its job. (Simon, Dickey, and Reece, 2013, Campbell Essential Biology 7th edition, pg.110)
- Where does the energy come from that allow plants to synthesize the necessary biological macromolecules that allow it to grow? Hint: It is NOT from sunlight. Explain your answer.
According to our textbook, the “starting material” for plants to transfer light or solar energy into chemical energy is a mixture of carbon dioxide and water, with a by-product of oxygen. These chemical energies are then stored within the bonds of sugar molecules. When the plant begins its process of photosynthesis, it must first get nutrients such as humans to eat to perform work. It will get its starting materials by getting water through its roots and carbon dioxide through its stomata, as well as releasing oxygen through its stomata. The energy is produced through photosynthesis. CO2 and H2O are the ingredients of photosynthesis. The glucose produced is what aids the plants in growing and producing healthy oxygen.
Campbell, N. A., Reece, J. B., & Simon, E. J. (2007). Essential biology. San Francisco, CA: Pearson Benjamin Cummings
(Simon, Dickey, and Reece, 2013, Campbell Essential Biology 7th edition, pg.108)
(Simon, Dickey, and Reece, 2013, Campbell Essential Biology 7th edition, pg.108- 110)