Question

If a$C_3$ plant and a$c_4$plant are placed together in a sealed illuminated box with sufficient moisture, the $C_4$plant thrives while the $C_3$ plant sickens and eventually dies. Explain.

Short answer

A C4 plant can photosynthesize at a significantly lower partial pressure of CO2 than a C3 plant. Additionally, the C3 plant reverses the effects of photosynthesis through photorespiration at very low partial pressures of CO2. The C4 plant keeps the partial pressure of CO2 in the sealed box so low that the C3 plant deteriorates through photorespiration. The C4 plant eats the C3 plant in effect

Step-by-step solution

Types of plants based on the respiratory processes

Botanists use the terms C3, C4, and CAM to categorize Earth's plants; these terms correspond to the number of first carbon compounds to which $C{O}_2$ is fixed. The C3 pathway is used by the majority of terrestrial plants. Certain respiratory processes occur in higher plants, in which the plants absorb oxygen in the presence of sunshine and exhale $C{o}_2$into the atmosphere. This is a completely different process than photosynthesis.

Photorespiration

Photorespiration is a metabolic route that happens in the C3 cycle or Calvin cycle when the carbon-fixing enzyme Rubisco reacts with oxygen rather than carbon dioxide.

It wastes energy and uses fixed carbon sources. When plants close their stomata to cope with water loss due to high temperatures, this mechanism occurs.

Explanation of different responses of plants in the sealed illumination box

Despite appropriate moisture, the temperature of the illumination box rises in the provided experiment. Photorespiration occurs as a result of the increased temperature. Photorespiration is well adapted in C4 plants; however, photorespiration is less capable in C3 plants.

Mesophyll cells, which use PEP carboxylase to fix CO2, and bundle sheath cells, which can sustain a high concentration of CO2 in the presence of Rubisco, are two types of cells found in the leaves of C4 plants.

Both of these characteristics are lacking in C3 plants, resulting in simple oxygen access to the Rubisco enzyme.

Hence, the C4plant thrives whereas the C3 plant becomes sick and eventually dies in the aforementionedexperiment.