Topic 5A Photosynthesis Revision

Front

In which parts of the chloroplast do the light-dependent and light-independent reactions occur?

Back

Thylakoid membranes and stroma

Answer explanation

The light-dependent reactions occur in the thylakoid membranes, where sunlight is captured, while the light-independent reactions (Calvin cycle) take place in the stroma, where glucose is synthesized.

Front

What is the role of light in the chloroplast?

Back

provide energy for photosynthesis

Answer explanation

The role of light in the chloroplast is to provide energy for photosynthesis, which is essential for converting carbon dioxide and water into glucose and oxygen.

Front

The two stages involved in ATP production during the light-dependent stage are:

Back

Photophosphorylation and electron transport chain

Answer explanation

The light-dependent stage of photosynthesis involves photophosphorylation, where ATP is produced, and the electron transport chain, which transfers electrons and generates energy. Thus, the correct answer is photophosphorylation and electron transport chain.

Front

In the electron transport chain (ETC), what occurs?

Back

Electrons are transferred through a series of proteins to produce ATP.

Answer explanation

In the electron transport chain, electrons are transferred through a series of proteins, which helps create a proton gradient that drives ATP production. This process is crucial for cellular respiration.

Front

The proton gradient is established during chemiosmosis by:

Back

the movement of protons across a membrane via the electron transport chain

Answer explanation

The proton gradient is established by the movement of protons across a membrane via the electron transport chain, which pumps protons into the intermembrane space, creating a gradient essential for ATP synthesis.

Front

Chemiosmosis produces ATP by:

Back

using a proton gradient to drive ATP synthase

Answer explanation

Chemiosmosis produces ATP by using a proton gradient to drive ATP synthase, which harnesses the energy from protons moving across the membrane to synthesize ATP from ADP and inorganic phosphate.

Front

What is the role of light in photolysis?

Back

split water molecules to release oxygen

Answer explanation

The role of light in photolysis is to split water molecules, which releases oxygen as a byproduct. This process is essential for photosynthesis, making the first answer choice correct.

Front

The H⁺ ions and electrons used to reduce NADP come from: water molecules, carbon dioxide, glucose, oxygen

Back

water molecules

Answer explanation

The H+ ions and electrons used to reduce NADP come from water molecules during the light-dependent reactions of photosynthesis, where water is split to release these components.

Front

What are the three main stages of the Calvin cycle?

Back

Carbon fixation, reduction, regeneration of RuBP

Answer explanation

The Calvin cycle consists of three main stages: carbon fixation, where CO2 is incorporated; reduction, where ATP and NADPH convert 3-PGA to G3P; and regeneration of RuBP, which allows the cycle to continue.

Front

Which enzyme is used during carbon fixation?

Back

Rubisco

Answer explanation

Rubisco, or ribulose bisphosphate carboxylase/oxygenase, is the enzyme responsible for catalyzing the first step of carbon fixation in the Calvin cycle, making it essential for photosynthesis.