In this lesson, you will learn about the various mechanisms used by eukaryotes to regulate their gene expression at the transcriptional and translational levels, about differential gene expression in cell types and the molecular biology of cancer.
By the end of this lesson, students should be able to:
- list and explain the various types of chromatin modification (e.g. histone acetylation, DNA unpacking, DNA methylation and chromatin phosphorylation).
- describe the organization of eukaryotic genes including the location and function of proximal and distal (enhancers) control elements, promoter, poly-A signal sequence.
- explain how control elements interact with transcriptional factors to affect transcription.
- explain the combinatory control of gene expression.
- describe regulation in the expression of albumin and crystallin genes in liver and lens cells and relate this regulation to cell differentiation.
- explain the last step in gene expression, that is the processing and degradation of proteins.
- explain how proteins are tagged with the small protein ubiquitin for destruction by proteasomes.
- differentiate between pro-oncogenes and oncogenes in the development of cancer.
- explain the roles of the Ras protein and the p53 gene in cell signalling in cancerous cells.
- describe the multi-step model for colorectal cancer.
Below is a thorough presentation on the regulation of gene expression in eukaryotes at the transcriptional level. Please watch it closely and take down detailed notes.
Control of Transcription Activity
In order to visualize how transcription is controlled by enhancers, activators and transcription factors watch the animation below. Once again write a narration of the events leading to the start of transcription and clearly state how enhancer, activators and transcription factors regulate gene expression at the transcriptional level.
Below is a Crossword Puzzle containing terminology on gene expression regulation in eukaryotes. Please print it our, completed and then uploaded to our site as homework. Use your notes to expand your vocabulary and to complete the puzzle.
The video lesson below introduces the mechanisms of gene expression control at the translation and post-translational level as well as the molecular changes (mutations) that lead to the uncontrol cell division in cancerous cells. Please watch it carefully and write down detailed notes.