C4 Plant Metabolism Spatial Separation

The video explains C4 metabolism, highlighting its efficiency in carbon fixation by separating CO2 intake and fixation into different cells. It details the roles of mesophyll and bundle sheath cells, the enzymatic pathway involving PEP carboxylase and malate, and uses a smuggling analogy to describe CO2 transport. C4 plants are shown to be well-adapted to high temperatures and low resources due to their efficient carbon fixation, avoiding photorespiration seen in C3 plants.

What is the primary difference between C3 and C4 metabolism?

• C4 metabolism involves spatial separation of carbon intake and fixation.

• C3 metabolism occurs in two different cells.

• C3 metabolism is more efficient in high temperatures.

• C4 metabolism uses oxygen instead of carbon dioxide.

In C4 plants, where does the initial intake of carbon dioxide occur?

• Bundle sheath cell

• Mesophyll cell

• Chloroplast

• Stomata

Which enzyme is responsible for converting bicarbonate to oxaloacetate in C4 metabolism?

• Malic enzyme

• PEP carboxylase

• Carbonic anhydrase

• Rubisco

What is the role of malic enzyme in the bundle sheath cell?

• It converts pyruvate to malate.

• It oxidizes and decarboxylates malate.

• It fixes carbon dioxide directly.

• It transports carbon dioxide across cells.

How do C4 plants avoid the unfavorable oxygenase activity of Rubisco?

• By increasing oxygen concentration in the bundle sheath cell.

• By using a different enzyme for carbon fixation.

• By creating a high CO2 concentration in the bundle sheath cell.

• By performing photosynthesis at night.

Why are C4 plants more suited to high temperatures and drought conditions?

• They can store more water in their cells.

• They require less sunlight for photosynthesis.

• They are more efficient in carbon fixation.

• They have a higher rate of photorespiration.

What is the main advantage of CAM metabolism over C4 metabolism?

• It separates carbon fixation and intake by time.

• It is more efficient in cooler climates.

• It separates carbon fixation and intake by space.

• It uses less energy overall.