Pigments are colored materials found in both plant and animal cells. They are responsible for the colors we see in a vast array of living things and even some man-made materials.
Pigments in Plants
- Leaves: Plant leaves contain several types of pigments, including chlorophylls (responsible for the green color), carotenoids (yellow and orange), and anthocyanins (red, purple, and blue). Harvard Forest provides more detail on leaf pigments and their functions. The color of leaves changes depending on the relative abundance of these pigments. For example, the yellow and orange colors become visible in autumn as chlorophyll breaks down. Let's Talk Science offers a good overview of plant pigments.
- Flowers, Fruits, and Tubers: Anthocyanins are prevalent in the colorful parts of many plants, such as flowers, fruits (like berries), and tubers (like potatoes). Their color varies depending on the pH; they appear red in acidic conditions and blue in alkaline conditions. NCBI - Anthocyanidins and anthocyanins delves deeper into these pigments.
- Other Plant Parts: Carotenoids can be found in various plant parts beyond leaves, including roots and fruits, contributing to the yellow to orange hues. USDA - The Chemistry Behind the Color explains the role of carotene in leaf coloration. Carotenoids are also produced by some microorganisms. NCBI - Natural Pigments Production
Pigments in Animals
- Skin, Hair, and Eyes: Pigments in animals determine the color of skin, hair, and eyes. These pigments can be melanin (responsible for various shades of brown and black), carotenoids (yellow and orange), and others. The reference material explicitly states this.
- Vertebrate Retinas: Vertebrate retinas contain rod cells (for low-light vision) and cone cells (for color vision), each containing different types of pigments that respond to specific wavelengths of light. PubMed and PNAS articles describe the adaptation of cone pigments.
Pigments in Art
Pigments are also used in art and paint making. Historically, various natural and synthetic pigments have been employed to create colors. Examples include zinc white and unusual pigments like Cu-Bi arsenate minerals found in historical paintings. The Met Museum and Heritage Science Journal provide examples of pigments used in art.
