Photosynthesis | Energy and matter in biological systems

Dr. Sammy explains photosynthesis, a crucial process for life on Earth, converting sunlight into chemical energy. The process involves light-dependent reactions in chloroplasts, producing ATP and NADPH, and the Calvin Cycle, which fixes carbon dioxide into organic molecules. Photosynthesis is essential for producing oxygen and forming the basis of the food chain.

What is the primary function of photosynthesis?

• To create heat energy

• To absorb carbon dioxide

• To convert light energy into chemical energy

• To produce oxygen

Which two substances are combined during photosynthesis to form carbohydrates?

• Carbon dioxide and water

• Oxygen and carbon dioxide

• Oxygen and water

• Nitrogen and water

What is the role of chlorophyll in photosynthesis?

• To transport water

• To store energy

• To absorb light energy

• To produce oxygen

Where do the light-dependent reactions of photosynthesis take place?

• In the stroma

• In the mitochondria

• In the thylakoid membrane

• In the cytoplasm

What is produced as a byproduct of the light-dependent reactions?

• Carbon dioxide

• Water

• Oxygen

• Glucose

What is the role of NADPH in photosynthesis?

• To fix carbon dioxide

• To absorb light energy

• To transport electrons and protons

• To produce oxygen

What molecule is often referred to as the 'energy currency' of the cell?

• NADPH

• ATP

• ADP

• Glucose

What is the main purpose of the Calvin cycle?

• To produce oxygen

• To absorb light energy

• To generate ATP

• To fix carbon dioxide into organic molecules

What is the significance of carbon fixation in the Calvin cycle?

• It produces oxygen

• It absorbs light energy

• It converts inorganic carbon into organic molecules

• It generates ATP

What happens to the byproducts of the light-independent reactions?

• They are released as waste

• They are stored in the chloroplast

• They are used to produce oxygen

• They are recycled back to the thylakoid