Question

Respiration and Fermentation 4. The titan arum (Amorphophallus titanum) has an enormous inflorescence up to 3 meters tall. The plant rarely flowers, but when it does visitors flock to botanical gardens, and in the forest pollinators are lured to the flowers in the night. The titan arum is able to generate heat and raise its temperature above ambient temperatures. Botanists have suggested that the ability to produce heat is important in these plants because it enhances the spread of the carrion-like scent to the far reaches of the tropical forest canopy. Clearly, these plants must have a high respiratory rate to produce tempera- tures as high as 36°C. How could you determine if the temperature is the result of cellular respiration? What features of the plant surface and cell structure might be present if respiration is actively occurring in the flowers? DIA: BioFlix jes Investigations, Videos, and Data Tables

Answer 1

The process of thermogenesis or heat generation in the titan arum flowers is a peculiar and less-understood phenomenon. Even scientists are unsure how these plants manage to generate temperatures that are higher than their surroundings.

Thermogenic plants are normally protogynous, i.e their female flowers mature before the male flowers, on the same plant. This reduces the rate of self-pollination. This could be the reason why these plants emit pungent odors, in order to attract insects for cross pollination.

Another feature of the plant surface is the large size of its flowers, as smaller flowers are incapable of producing heat.

The heat generation is actually a by-product of cellular respiration, and is produced in the mitochondria. This can be proved by the presence of the AOX (Alternative Oxidase) enzyme which is found in the Electron Transport Chain in mitochondria.