This is the series of blocks Amino acid substitution matrices (BLOSUM), all of which are derived based on direct on direct observation for every possible amino acid substitution in multiple sequence alignments.
A volt-ampere (VA) is the unit used for the apparent power in an electrical circuit, equal to the product of root-mean-square (RMS) voltage and RMS current.[1] In direct current (DC) circuits, this product is equal to the real power (active power) [2] in watts.
Quick Answer. VAC is an electrical voltage in an alternating current circuit. The power system supplying homes and businesses in the United States uses AC 120 V, while in Europe the system uses AC 240 V. Continue Reading.