Transcription (Edexcel GCSE Biology)

This lesson describes the key steps involved in transcription, the 1st stage of protein synthesis. The PowerPoint and accompanying resource are part of the first lesson in a series of 2 lessons which have been designed to cover the content of point 3.8 of the Edexcel GCSE Biology specification.

According to the specification, the students are expected to know this process in considerable detail, and the lesson has been planned to reflect this. In a previous lesson in topic 3, the students were introduced to the definition of a gene as a section of a DNA molecule that codes for the sequence of amino acids in a protein. They will learn that this represents coding DNA, so time is then taken to explain that not all DNA codes for proteins and that there are sections of non-coding DNA located in front and behind each gene. This is vital information as it leads into the start of the process, where the binding of RNA polymerase to a section of non-coding DNA located in front of the gene is the trigger for the start of transcription of that particular gene. Moving forwards, a step by step guide describes the key steps which include the lining up of the RNA nucleotides against the exposed bases and the formation of mRNA through the reactions catalysed by RNA polymerase. Students are given key details of RNA nucleotides, specifically the inclusion of uracil bases, and an understanding check challenges them to determine the sequence of RNA bases that will line up against a template strand. These current understanding checks along with prior knowledge checks are found throughout the lesson to allow the students to assess their progress and to challenge them to make links to previous lessons.