Exploring Photosynthesis: Light and Dark Reactions

The video explains photosynthesis, which occurs in two main steps: the light reaction and the dark reaction. The light reaction takes place in the thylakoid membranes, capturing light energy to produce ATP and NADPH while releasing oxygen. The dark reaction, or Calvin cycle, occurs in the stroma, using ATP and NADPH to convert carbon dioxide into glucose. Variations in photosynthesis, such as C4 and CAM pathways, are also discussed, highlighting adaptations in different plants to conserve water.

What is the first step of photosynthesis?

• Light reaction

• Krebs cycle

• Calvin cycle

• Dark reaction

Where does the light reaction occur?

• Nucleus

• Stroma

• Mitochondria

• Thylakoid discs

What is produced as a by-product of the light reaction?

• Water

• Glucose

• Oxygen

• Carbon dioxide

What is the main energy currency of cells produced during the light reaction?

• NADPH

• ATP

• ADP

• NADP+

What is another name for the dark reaction?

• Electron transport chain

• Calvin cycle

• Krebs cycle

• Light reaction

How many carbon dioxide molecules are used in the Calvin cycle to create one glucose molecule?

• 3

• 12

• 6

• 9

What is the formula for glucose?

• C6H10O6

• C5H12O6

• C5H10O5

• C6H12O6

Which type of plants make a four-carbon compound to prevent water loss?

• C4 plants

• C3 plants

• All plants

• CAM plants

How do CAM plants conserve water?

• By closing stomata during the night

• By opening stomata during the day

• By closing stomata during the day

• By opening stomata during the night

What is the main purpose of photosynthesis?

• To produce water

• To produce carbon dioxide

• To produce glucose

• To produce oxygen