Bitumen emulsion is a mixture of fine droplets of bitumen and water. Since bitumen is a petroleum product, it doesn't mix with water and needs an emulsifying agent to stabilize the mixture. The emulsion is used predominantly in road construction and maintenance because it's easier to work with and less hazardous than hot bitumen. Bitumen emulsions can be either anionic or cationic, depending on the emulsifying agent used, which determines their adherence to different types of aggregations. They're eco-friendlier, as their application doesn't require as much energy due to lower heating requirements and they emit fewer volatile organic compounds (VOCs).

Amino acids, the building blocks of proteins, are specified by their unique side chains, or R groups, which determine their chemical properties and functions. Each amino acid has a central carbon atom bonded to an amino group (-NH2), a carboxyl group (-COOH), at least one hydrogen atom, and a variable R group. This R group imparts specific characteristics such as polarity, charge, size, and reactivity, influencing how amino acids interact with each other and their environment. For example, hydrophobic amino acids have nonpolar R groups that tend to cluster inside proteins, away from water, while hydrophilic amino acids with polar or charged R groups face outward, interacting with water. In genetic coding, each of the 20 standard amino acids is specified by a three-letter code derived from the mRNA sequence during protein synthesis. This genetic code ensures that the correct sequence of amino acids forms a functional protein.

Black carbon, unlike greenhouse gases that trap heat in the atmosphere, has a different influence due to its unique properties. When released into the atmosphere, black carbon particles absorb sunlight and convert it to heat, directly warming the atmosphere. This absorption process can have a heat-amplifying effect, especially when these particles settle on snow and ice, reducing their albedo (reflectivity) and leading to faster melting. This is the opposite of many aerosols that reflect sunlight back into space, thus cooling the Earth. Black carbon's short atmospheric lifespan, ranging from days to weeks, contrasts with long-lived greenhouse gases but its immediate impact on atmospheric warming and ice melting is significantly potent, showcasing its unique, warming effect on the climate system.