Description of Step Step Order Light energy is collected by pigment molecules in
ID: 211920 • Letter: D
Question
Description of Step Step Order Light energy is collected by pigment molecules in photosystem II and is used to energize an electron. This electron leaves the pigment molecule and is replaced by a free electron that comes from splitting water into oxygen and hydrogen atoms. Light energy energizes an electron in a pigment molecule in photosystem I. The electron is then released from the photosystem and replaced by a low-energy electron coming off of an electrorn transfer chain. The electron ejected from photosystem I passes through a short electron transfer chain, then combines with NADP, hydrogen ion joins as well to form NADPH. The light reactions create a higher concentration of hydrogen lons inside the inner membrane system than outside of it. These hydrogen ions flow out through special protein structures in the membrane, which powers the creation of ATP The energized electron is used to power the transfer of hydrogen ions across the membrane by passing through an electron transfer chain. The light-independent reactions of photosynthesis occur in the stroma of the chioroplast; these reactions are referred to as the Calvin-Benson cycle. This diagram illustrates the patterm of the reactions of the Calvin-Benson cyde. You can think of the Calvin-Bensen cydle as having three basic stages, each with a specific purpese. Study the dagram and then answer the questions that follow. (Hint You will Identify the purpose of each stage and what is occuming in the reactions Stage 1i Carbon Pixation Carbon fixation first eccurs at this stage when carbon dioxide is attached to which molecule? O Glucose 0 Stage 2: Creating Glucose 12 molecules of PGA use the energy from ATP and NADPH to rearrange and form 12 molecules of 12 NADP FGAL Stage 3: Regenerating RuBP ATP provides the energy needed to rearrange 10 molecules of PGAL Into 6 molecules of Quep glucose Summary The Calvin-Benson cyde uses molecules of carbon dioxide to create of glucose. i molecufe 12 molecolesExplanation / Answer
1. Option B is correct.
During carbon fixation step of the C3 cycle, CO2 is attached with RuBP.
2. Option C is correct.
12 molecules of PGA use energy from ATP and NADPH to produce 12 molecules of glyceraldehyde-3-phosphate (PGAL).
3. Option A is correct.
ATP provides the energy needed to rearrange 10 molecules of PGAL into 5 molecules of RuBP.
In C3 cycle, six CO2 molecules are required to produce one glucose molecule.