Understanding the Absorption Theory requires knowing the intricate structures of leaves and the characteristics of light in nature.
In the realm of photosynthetic organisms, plants stand out as the sole beings possessing leaves, though not every plant boasts this feature.
Picture a leaf as a solar collector packed with cells geared for photosynthesis. Within the leaf's cells, essential elements for photosynthesis—water
and carbon dioxide—enter, while the byproducts—sugar and oxygen—exit.
The journey of water from the roots, propelled through specialised xylem cells, is crucial for sustaining plants.
To combat desiccation, plants have evolved stomata, small openings facilitating the exchange of gases. Carbon dioxide
infiltrates through these stomata, and oxygen exits during photosynthesis. However, this exchange comes at the cost of
significant water loss, exemplified by cottonwood trees shedding 100 gallons of water per scorching desert hour. In contrast,
single-celled and aquatic autotrophs absorb carbon dioxide without the need for specialised
To unravel the Absorption Theory, one must grasp the nature of light. When white light traverses a prism, it splits into various colours based on wavelength. Wavelength, the distance between peaks or troughs, inversely correlates with energy—longer wavelengths exhibit lower energy. Visible light constitutes only a fraction of the electromagnetic spectrum, with colours shifting from red (longer wavelength, less energy) to violet (shorter wavelength, more energy).
The chemical equation 6H2O + 6CO2 → C6H12O6 + 6O2 encapsulates photosynthesis. Plants, with their diverse pigments, absorb energy crucial for this process.
Pigments, substances absorbing light, contribute to the vivid colors in nature. Chlorophyll,
the green pigment universal in photosynthetic cells, absorbs all visible light wavelengths except green,
which it reflects. Accessory pigments, like chlorophyll b, xanthophylls, and carotenoids, fill in gaps by absorbing unutilized energy.
Chlorophyll's complexity manifests through variations among plants and other photosynthetic organisms. While chlorophyll a is universal,
accessory pigments bridge the absorption gaps. The intricate interplay between pigments results in absorption spectra, determining the effectiveness
of different wavelengths in generating electrons during photosynthesis.
In the world of chlorophyll, the hues of green emerge from distinct absorption peaks, creating variations in shades.
Chlorophyll a absorbs predominantly violet/blue and red light, while chlorophyll b leans towards blue and orange-red. The
intricate dance of these pigments gives rise to the diversity of green tones in the plant kingdom, showcasing that not all greens are created equal.