Introduction to electromagnetism is a quantity used to determine how a particle will behave in an electric field. There are three possible "types" of charge: positive, negative, and neutral. However, the distinction between positive and negative is by convention only. Electric charge is quantized in units of the elementary charge, formula_1, where a proton has a charge of formula_2 and an electron has a charge of formula_3. The SI unit of charge is the coulomb. The elementary charge formula_1 was first measured by Robert Millikan in his oil drop experiment in which the electric force on the particle is set to exactly counter
Ribonucleoprotein particle Ribonucleoprotein particle A ribonucleoprotein particle or RNP is a complex formed between RNA and RNA-binding proteins (RBPs). The term RNP foci can also be used to denote intracellular compartments involved in processing of RNA transcripts. RBPs interact with RNA through binding motifs. Aromatic amino acid residues in this RNA binding motif result in stacking interactions with RNA. Lysine residues in the helical portion of RNA binding proteins help to stabilize interactions with nucleic acids. This nucleic acid binding is a result of the force of attraction between the positive electrical charge of lysine side chains and the negative electrical charge