Center of mass rigid body, the gravity forces will not cause the body to rotate, which means the weight of the body can be considered to be concentrated at the center of mass. The linear and angular momentum of a collection of particles can be simplified by measuring the position and velocity of the particles relative to the center of mass. Let the system of particles "P", "i"=1...,"n" of masses "m" be located at the coordinates r with velocities v. Select a reference point R and compute the relative position and velocity vectors, The total linear and angular momentum vectors relative to the
N,N-Dimethyltryptamine (step 1). The resulting decarboxylated tryptophan analog is tryptamine. Tryptamine then undergoes a transmethylation (step 2): the enzyme indolethylamine-N-methyltransferase (INMT) catalyzes the transfer of a methyl group from cofactor S-adenosyl-methionine (SAM), via nucleophilic attack, to tryptamine. This reaction transforms SAM into S-adenosylhomocysteine (SAH), and gives the intermediate product "N"-methyltryptamine (NMT). NMT is in turn transmethylated by the same process (step 3) to form the end product "N","N"-dimethyltryptamine. Tryptamine transmethylation is regulated by two products of the reaction: SAH, and DMT were shown "ex vivo" to be among the most potent inhibitors of rabbit INMT activity. This transmethylation mechanism has been