C4 Photosynthesis

Question 2

What is the main adaptation of C4 photosynthesis in hot climates?

Answer 2

CO₂ is fixed into malic acid (4C) via PEPcase

This adaptation helps plants efficiently use CO₂ and minimize water loss.

Question 3

What happens to malate in C4 photosynthesis?

Answer 3

Malate moves to bundle sheath cells and releases CO₂

This process helps maintain low oxygen levels around Rubisco, reducing photorespiration.

Question 4

Why is C4 photosynthesis efficient above 25°C?

Answer 4

It reduces photorespiration by keeping O₂ low around Rubisco

Examples of C4 plants include maize and sugarcane.

Question 5

What enzyme is involved in fixing CO₂ into malic acid in C4 photosynthesis?

Answer 5

PEPcase

PEPcase stands for phosphoenolpyruvate carboxylase.

Question 6

Fill in the blank: In C4 photosynthesis, CO₂ is fixed into _______.

Answer 6

malic acid (4C)

Malic acid plays a crucial role in the carbon fixation process.

Question 7

True or False: C4 photosynthesis is less efficient in hot climates.

Answer 7

False

C4 photosynthesis is specifically adapted to be efficient in hot conditions.