Photosynthesis: Practice Questions

During the light-dependent reaction, the chemiosmotic theory describes the movement of protons. Where do protons accumulate to create the electrochemical gradient required for ATP synthesis, and what is the source of these protons?

During the process of chemiosmosis in the thylakoid, what provides the energy required to actively pump protons (\(H^+\)) from the stroma into the thylakoid lumen?

A researcher found that 30 molecules of triose phosphate (TP) were produced in the stroma of a chloroplast over a period of time. How many of these molecules are required to regenerate the ribulose bisphosphate (RuBP) used in the fixation of those carbons, and how many are net gain for hexose production?

In the light-dependent reaction of photosynthesis, what is the specific role of photolysis in the thylakoid?

During the light-dependent reaction of photosynthesis, light energy is absorbed by chlorophyll, leading to photoionisation. Which of the following statements best describes the immediate consequence of this process in the production of ATP and reduced NADP?

In the light-dependent reaction of photosynthesis, what is the role of photolysis in maintaining the continuous flow of electrons through the electron transfer chain?

In the chemiosmotic theory, explain how the electron transfer chain (ETC) facilitates the synthesis of ATP across the thylakoid membrane.

Explain why the process of photoionisation is essential for the production of ATP during the light-dependent reaction of photosynthesis.

In the light-dependent reaction of photosynthesis, ATP and reduced NADP are produced through the process of chemiosmosis.

(a) Describe the role of photoionisation in initiating the movement of electrons through the electron transfer chain (ETC). (1 point)

(b) Explain how the energy from these electrons is used to create an electrochemical gradient that leads to the synthesis of ATP. (2 points)

In the light-independent reaction of photosynthesis, the enzyme rubisco plays a critical role.

(a) Describe the reaction catalysed by rubisco, including the substrates and the products formed. (2 points)
(b) Explain why the concentration of Glycerate 3-phosphate (GP) initially increases while the concentration of Ribulose bisphosphate (RuBP) decreases when the light is turned off. (3 points)