Pumpkins turn orange because they stop producing chlorophyll, revealing underlying pigments called carotenoids.
Here's a more detailed explanation:
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Chlorophyll's Role: While growing, pumpkins, like all green plants, produce chlorophyll. This pigment is essential for photosynthesis, the process where plants convert sunlight into energy. Chlorophyll masks other pigments present in the pumpkin, giving it a green color.
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Slowing Down and Stopping Chlorophyll Production: As fall approaches and the nights get longer, the pumpkin vine starts to slow down its growth. Consequently, it reduces and eventually stops producing chlorophyll.
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Carotenoids Revealed: As chlorophyll degrades, the other pigments present in the pumpkin, called carotenoids, become visible. Carotenoids are responsible for the orange, yellow, and red colors we see in many fruits and vegetables, including carrots and, of course, pumpkins.
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The Chemical Change: This change is a natural chemical process. The green chlorophyll molecules break down, allowing the pre-existing orange carotenoid pigments to shine through.
In essence, the pumpkin doesn't become orange; it reveals its orange color as the green chlorophyll fades away.
