And in the 20s core is where we begin to break down the protein into smaller peptides that consist of about seven to nine amino acids in length. And also what happens inside a 20s protein is we have an enzyme known as Isappeptidase that begins to remove the ubiquitin molecules. Because the ubiquitant molecules are not broken down our cells reuse the ubiquitan molecules over and over and over. So we see that the proteosome consists of a core of 20s subunit and 219s subunits position at both ends of this core. Now, the 19s subunits are the regulatory units and the 20s are the catalytic subunits. So in a way you can imagine that the 20s subunit is like a garbage disposal.