Light Dependent Reactions Flashcards
What are the general reactants and products of photosynthesis
the general reactants of photosynthesis are carbon dioxide, water, and light energy, while the products are glucose and oxygen
How are electrons able to get to an excited state?
by absorbing energy, such as light energy, which promotes them to a higher energy level
What does it mean to say that an electron is in an excited or ground state?
When an electron is at its lowest energy level, it is in the ground state. An excited state refers to when an electron has absorbed energy and moved to a higher energy level
Explain how photosynthesis can capture light energy and get electrons to an excited state?
In the photosystem, light energy is absorbed by pigments like chlorophyll, exciting electrons to a higher energy level. These excited electrons are then passed along a series of proteins in the electron transport chain within the thylakoid membrane, creating a proton gradient that drives ATP synthesis.
Describe each step of ETC of the light-dependent reaction
- Photon Absorption: Chlorophyll in photosystem II (PSII) absorbs light, exciting electrons.
- Water Splitting: Water splits, releasing electrons, protons, and oxygen.
- Electron Transport Chain (ETC): Excited electrons move through carriers in the thylakoid membrane.
4.Proton Pumping: Energy from electrons pumps protons into the thylakoid lumen, creating a gradient.
5.ATP Synthesis: Protons flow back through ATP synthase, producing ATP.
6.Photosystem I (PSI): Chlorophyll in photosystem I (PSI) absorbs another photon, further exciting electrons.
7.NADPH Production: Excited electrons from PSI reduce NADP+ to NADPH via carriers like ferredoxin.
What are the reactants and products?
The reactants in the Electron Transport System are NADH and FADH2, and the products are ATP and water.
What is the source?
The source of energy in this process is the movement of electrons along the electron transport chain.
What is the final electron acceptor?
The final electron acceptor is usually oxygen, which combines with electrons and protons to form water.
Where does the b6-f complex pump the protons out to?
The b6-f complex pumps protons from the stroma into the thylakoid lumen.
What is photophosphorylation?
Photophosphorylation is the process of using light energy to convert ADP and inorganic phosphate into ATP.
Explain the process of photophosphorylation
There are two types of photophosphorylation: cyclic and non-cyclic. In non-cyclic photophosphorylation, light energy is used to split water molecules, releasing electrons that move through the electron transport chain, leading to the production of ATP and NADPH. In cyclic photophosphorylation, only ATP is produced as electrons cycle back to the photosystem.
