RNA and Protein Synthesis

Overview of the Process

• RNA copy is completed and moves into the outer part of the cell.
• Components of a molecular machine assemble around the RNA to form a ribosome.
• Ribosome translates genetic information in the RNA into a string of amino acids, forming a protein.

Role of Transfer Molecules

• Special transfer molecules (illustrated as green triangles) bring amino acids to the ribosome.
• Amino acids are shown as small red tips attached to the transfer molecules.
• There are different transfer molecules for each of the 20 amino acids.
• Each transfer molecule carries a three-letter code matched with the RNA in the ribosome.

Inside the Ribosome

• RNA is pulled through the ribosome like a tape.
• The genetic code for each amino acid is read off three letters at a time.
• These three letters are matched to three corresponding letters on the transfer molecules.
• When the correct transfer molecule connects, its amino acid is added to the growing protein chain.

Real-Time Protein Assembly

• Assembled protein begins to emerge from the ribosome after a few seconds.
• Ribosomes can synthesize any protein based on the genetic message on the RNA.

Example: Hemoglobin Synthesis

• The end product of the process can be hemoglobin.
• Cells in bone marrow produce a hundred trillion hemoglobin molecules per second.
• Hemoglobin is essential for delivering oxygen to muscles, brain, and vital organs.