exit ticket - C1.3 Photosynthesis HL

Which structure in the chloroplast is responsible for capturing light energy?

• Chlorophyll b molecules

• Outer membrane

• Thylakoid membrane

• Stroma

Answer explanation

The thylakoid membrane contains chlorophyll molecules that capture light energy during photosynthesis, making it the key structure for light absorption in chloroplasts.

Which process produces ATP in the light-dependent reactions?

• Glycolysis

• Chemiosmosis

• Carbon fixation

• Photolysis

Answer explanation

Chemiosmosis is the process that produces ATP during the light-dependent reactions of photosynthesis. It occurs as protons flow back across the thylakoid membrane, driving ATP synthase to generate ATP.

What is the role of the photosystems in photosynthesis?

• Absorbing light and transferring energy to electrons

• Reducing NADP+ to NADPH

• Pumping protons across the membrane

• Splitting water molecules

Answer explanation

Photosystems are crucial in photosynthesis as they absorb light energy and transfer it to electrons, initiating the process of converting light energy into chemical energy.

Which pigment absorbs light most efficiently in the red and blue regions of the spectrum?

• Xanthophyll

• Chlorophyll a

• Carotene

• Chlorophyll b

Answer explanation

Chlorophyll a absorbs light most efficiently in the red and blue regions of the spectrum, making it the primary pigment in photosynthesis. Other pigments like xanthophyll and carotene absorb light but less effectively in these regions.

Where in the chloroplast does the Calvin cycle occur?

• Thylakoid space

• Inner membrane

• Stroma

• Thylakoid membrane

Answer explanation

The Calvin cycle occurs in the stroma of the chloroplast, where it utilizes ATP and NADPH produced in the thylakoids to convert carbon dioxide into glucose.

What is the final electron acceptor in the light-dependent reactions?

• Water

• NADP+

• Oxygen

• ATP

Answer explanation

In the light-dependent reactions of photosynthesis, NADP+ serves as the final electron acceptor. It accepts electrons and protons to form NADPH, which is crucial for the subsequent light-independent reactions.

How is oxygen produced in photosynthesis?

• By splitting water molecules in photosystem II

• From the oxidation of NADPH

• From the reduction of CO2

• During the regeneration of RuBP

Answer explanation

Oxygen is produced in photosynthesis by splitting water molecules in photosystem II. This process releases oxygen as a byproduct, while electrons are used in the light reactions to generate energy for the plant.

What is the main enzyme involved in carbon fixation during the Calvin cycle?

• Carboxylase oxidase

• Rubisco

• ATP synthase

• NADP reductase

Answer explanation

The main enzyme involved in carbon fixation during the Calvin cycle is Rubisco. It catalyzes the reaction of carbon dioxide with ribulose bisphosphate, making it essential for the process of photosynthesis.

What is the product of cyclic photophosphorylation?

• Glucose

• Oxygen

• ATP

• NADPH

Answer explanation

Cyclic photophosphorylation primarily produces ATP through the process of electron transport in photosynthesis, while glucose and NADPH are products of other pathways. Oxygen is released during non-cyclic photophosphorylation.

What is the purpose of accessory pigments in photosynthesis?

• To transport electrons

• To increase the absorption of light across more wavelengths

• To catalyse the Calvin cycle

• To reduce NADP+

Answer explanation

Accessory pigments enhance photosynthesis by capturing light energy at different wavelengths, allowing plants to utilize a broader spectrum of light for energy production.