Bishop Year 13 Biology

A reminder that all PAG books are due in this Thursday - please bring to lesson.

- Recap of types of genetic mutation - Definition of "operon" as "a cluster of genes under the control of a single promoter" - Definition of promoter as "a region of DNA near the start of a coding sequence where RNA polymerase can bind to begin transcription" - Introduction of the need for the lac operon in E.coli (usually respires using glucose so it would be wasteful to express necessary genes all the time, genetic switch required to facilitate detection of lactose followed by expression of necessary genes - Discussion of the role of lactose permease (transport protein) and beta-galactosidase (hydrolyses the disaccharide) HOMEWORK - get completed PLCs emailed in AND revise this topic for mini test Thursday

- Discussion of the broad categories of mutations (chromosome and gene) - Division of gene mutations into point and indel mutations - Division of point mutations into silent, missense and nonsense mutations (with examples) - Comparisons of the varying effects of the different types of mutations, with indel and nonsense often being the most detrimental - indel mutations cause a FRAME SHIFT in most circumstances meaning that every subsequent triplet is affected by the mutation - Discussion of the need for differential gene expression - this allows cells to become SPECIALISED - they need to express different genes at different times - Discussion of the different types of gene expression control/regulation: 1. Transcriptional 2. Post-transcriptional 3. Post-translational HOMEWORK - revise for mutations quiz, complete the mutations questions sheet and complete the year 12 PLC and bring on a USB