 Hi everyone, this is the 7th lecture of the biochemistry lecture series topic protein synthesis. In this lecture, we will discuss the basic structure and function of DRNA molecule. To understand the concept in detail, please stay tuned till the end of the video. If you haven't subscribed the channel, please do not forget to subscribe the basic science series YouTube channel to show your support by simply clicking the subscribe button present on the lower right corner of your screen. Alright, before we move ahead, let's do a recap of the previous lecture. In the previous lecture, we discussed about RNA editing. RNA editing is a molecular process through which cells can make discrete changes to specific nucleotide sequences within an RNA molecule. If you have any questions regarding the topic, please write the questions in the comment section. I'll do my best to address those questions. I will also provide the link to the previous video in the description box. Okay, let's start the lecture by understanding what is a TRNA molecule or also known as transfer RNA molecule. The transfer ribonucleic acid is a type of RNA molecule that helps decode a messenger RNA sequence into a protein sequence. TRNA is an adapter molecule composed of RNA, typically 76 to 90 nucleotides in length. It serves as a physical link between the mRNA and the amino acid sequence of the protein. TRNA does this by carrying an amino acid to the protein synthetic machinery of the cell. To further understand the TRNA charging on amino acid activation, you need to understand the basic structure of a TRNA molecule. So without any further delay, let's understand the structure of the TRNA molecule. The TRNA molecule has a 5-prime terminal phosphate group. The acceptor stem of TRNA is a 7 to 9 base pair stem made by the base pairing of 5-prime terminal nucleotide with the 3-prime terminal nucleotide, which contains CCA 3-prime terminal group used to attach the amino acids. Next is the D-arm. It is a 4 to 6 base pair stem ending in a loop that often contains dihydrouridin. The anticodon arm of TRNA is a 5 base pair stem and its loop contains the anticodon. And finally the T-arm that is 4 to 5 base pair stem containing the sequence T-size C, where psi is pseudouridin. Since we understood what is the basic function of TRNA molecule and the structure of a TRNA molecule, let's jump on to the final topic that is TRNA charging or amino acid activation. Amino acid activation, also known as amino isylation or TRNA charging, refers to the attachment of an amino acid to its transfer RNA molecule. In the first step, amino isyl transferase binds adenosine triphosphate molecule to amino acid and a pyrophosphate molecule is released. In the second step, amino isyl-TRNA synthetase binds AMP-tact amino acid to its TRNA molecule. During amino acid activation, the amino acids are attached to their corresponding TRNA molecules. The coupling reactions are catalyzed by a group of enzymes called amino-syl-TRNA synthetases. The amino acid is coupled at the 3 prime end of TRNA molecule via an ester bond. The formation of the ester bond conserves a considerable part of the energy from the activation reaction. This stored energy provides the majority of the energy needed for peptide bond formation during translation. The specificity of amino acid activation is as critical for the translational accuracy as the correct matching of the codon and the anticodon. The reason for that is ribosomes only sees the anticodon of the TRNA during translation, thus the ribosomes will not be able to discriminate between TRNA with the same anticodon but linked to different amino acids. With this final note I conclude this lecture and I hope the lecture was helpful for you to understand the function and structure of TRNA molecule. If you liked the video please press the like button, if you don't like the video please press the dislike button and do subscribe to the channel. Thank you for your support and I will see you in the next lecture.