Understanding Light-Dependent Reactions

What is the primary function of light-dependent reactions?

• To store energy in the form of starch.

• To convert light energy into chemical energy (ATP and NADPH) and produce oxygen.

• To absorb carbon dioxide and release glucose.

• To facilitate the process of cellular respiration.

Where do light-dependent reactions occur in the chloroplast?

• Stroma

• Cytoplasm

• Outer membrane

• Thylakoid membranes

What are the two main products of light-dependent reactions?

• ATP and NADPH

• Glucose and Oxygen

• RuBP and G3P

• FADH2 and CO2

Which pigment is primarily responsible for capturing light energy?

• Carotene

• Chlorophyll

• Phycobilin

• Xanthophyll

What role do water molecules play in light-dependent reactions?

• Water molecules act as a buffer to stabilize the reaction environment.

• Water molecules are used to absorb sunlight and generate glucose.

• Water molecules are converted into ATP during the reactions.

• Water molecules are split to provide electrons and protons, and release oxygen.

How is ATP generated during the light-dependent reactions?

• ATP is generated through photophosphorylation via ATP synthase, driven by a proton gradient created during the light-dependent reactions.

• ATP is formed by the breakdown of glucose during photosynthesis.

• ATP is produced by glycolysis in the chloroplasts.

• ATP is generated through the Calvin cycle using carbon dioxide.

What is the significance of the electron transport chain in these reactions?

• The electron transport chain is involved in photosynthesis and generates oxygen.

• The electron transport chain produces glucose and releases carbon dioxide.

• The electron transport chain converts ATP into ADP and phosphate.

• The electron transport chain generates ATP and reduces oxygen to water.

Which photosystems are involved in the light-dependent reactions?

• Photosystem I and Photosystem III

• Photosystem A and Photosystem B

• Photosystem X and Photosystem Y

• Photosystem II and Photosystem I

How does the pH gradient contribute to ATP synthesis?

• The pH gradient has no effect on ATP synthesis processes.

• The pH gradient drives proton flow through ATP synthase, facilitating ATP synthesis.

• The pH gradient directly converts glucose into ATP without ATP synthase.

• The pH gradient inhibits ATP synthase activity, reducing ATP synthesis.

What is the role of NADP+ in light-dependent reactions?

• NADP+ is a byproduct of the light-dependent reactions.

• NADP+ is used to produce ATP directly.

• NADP+ acts as a catalyst in the Calvin cycle.

• NADP+ serves as an electron carrier, becoming NADPH during light-dependent reactions.