Cellulose is commonly used in food production as an anti-caking agent or to add fiber, and it's broadly found in grated or shredded cheeses to prevent clumping. It's important to note that cellulose is a plant-based fiber and is generally considered safe for consumption. However, the presence and amount of cellulose can vary among cheese brands and types. Some consumers prefer cheeses without added cellulose, seeking products labeled as "cellulose-free" for a more natural cheese experience. It's prudent to read cheese labels if you're concerned about additives. Cheeses, especially pre-packaged and pre-shredded varieties, are more likely to contain cellulose. Artisanal cheeses and those freshly grated or cut from a block are less likely to have any added cellulose.

Animals produce a variety of color pigments, primarily classified into three types: melanins, carotenoids, and porphyrins. Melanins, ranging from black and brown to yellow and red tones, are the most widespread, contributing to skin, hair, and feather colors. Carotenoids, which animals often obtain through their diet, manifest as bright reds, oranges, and yellows, prominently seen in bird plumage and fish scales. Porphyrins are unique, producing a spectrum of colors, including some greens and reds, by reflecting light in specific ways. While these pigments provide camouflage, mating advantages, and protection from UV light, the biological mechanisms and genetic control over pigment synthesis and distribution are complex, varying significantly across different species.

The amino acid critical for the crosslinking of keratin fibers is cysteine. Cysteine contains a sulfur atom in its side chain, which allows it to form strong disulfide bonds with other cysteine residues. These disulfide bridges are crucial for providing structural support and rigidity to keratin, a protein prominently found in hair, nails, and the outer layers of skin. Through the formation of these crosslinks, keratin fibers gain the strength and resilience necessary to perform their protective and structural roles in the body. Thus, the presence and distribution of cysteine residues within keratin are key determinants of the mechanical properties and overall integrity of keratinized tissues.