sentences:  In biochemistry, a tether is a molecule that carries one or two carbon intermediates from one active site to another.They are commonly used in lipid synthesis, gluconeogenesis, conversion of pyruvate into Acetyl CoA via PDH complex.Common tethers are lipoate -lysine residue complex associated with dihydrolipoyl transacetylase, which is used for carrying hydroxyethyl from hydroxyethyl TPP.