Begin is the common term: to begin knitting a sweater. Commence is a more formal word, often suggesting a more prolonged or elaborate beginning: to commence proceedings in court. Initiate implies an active and often ingenious first act in a new field: to initiate a new procedure.
Structure of the trp operon. The trp operon is an operon â a group of genes that are used, or transcribed, together â that codes for the components for production of tryptophan. The trp operon is present in many bacteria, but was first characterized in Escherichia coli.The operon is regulated so that when tryptophan is present in the environment, the genes for tryptophan synthesis are not expressed.It was an important experimental system for learning about gene regulation, and is commonly used to teach gene regulation.he trp operon is present in many bacteria, but was first characterized in Escherichia coli. The operon is regulated so that when tryptophan is present in the environment, the genes for tryptophan synthesis are not expressed.
a glycoprotein hormone secreted mainly by the kidney. A profactor, erythropoietinogen, is first produced in the liver, transferred to the kidney and converted to active erythropoietin in the kidney. The erythropoietin acts on stem cells of the bone marrow to stimulate red blood cell production (erythropoiesis).rythropoietin. A hormone produced by the kidneys that stimulates the production of red blood cells by bone marrow. Mentioned in: Dialysis, Kidney. kidney-derived protein promoting erythrocyte formation within bone marrow.