Payments-in-lieu-of-taxes (if paid by another government, report at Intergovernmental Revenue; if paid by a private organization, use code U99; and if paid by another agency or utility of the same government, exclude entirely from revenue).
Figure 1-1: A flow chart of the two types of cofactors. Apoenzyme-An enzyme that requires a cofactor but does not have one bound. An apoenzyme is an inactive enzyme, activation of the enzyme occurs upon binding of an organic or inorganic cofactor. Holoenzyme-An apoenzyme together with its cofactor. A holoenzyme is complete and catalytically active. Most cofactors are not covalently bound but instead are tightly bound. However, organic prosthetic groups such as an iron ion or a vitamin can be covalently bound.
A ribozyme is a polyribonucleotide (RNA molecule) with enzymatic activity. They are sometimes also referred to as RNA enzymes however, to avoid confusion with ribonucleoproteins in which the RNA lacks catalytic activity, ribozyme is generally preferred. Ribozymes have been found in every known cell and are essential to cell functioning. The most well known example of an essential ribozyme is the 28S rRNA (called the 23S rRNA in prokaryotes), which carries out the aminoacyltransferase (peptide-lengthening) activity of ribosomes.