Gene Control
- The nucleus of every cell in the human body contains the same genes
- However, not every gene is expressed in every cell
- In addition, not all of these genes are expressed all the time
- There are several mechanisms that exist within cells to make sure the correct genes are expressed in the correct cell at the correct time
- These mechanisms are known as regulatory mechanisms
- They control which genes are expressed at different points in time (e.g. during development)
- There are three main types of regulatory mechanisms, including:
- Regulation at the transcriptional level (i.e. regulatory mechanisms that occur during transcription)
- Regulation at the post-transcriptional level (i.e. regulatory mechanisms that occur after transcription)
- Regulation at the post-translational level (i.e. regulatory mechanisms that occur after translation)
- These regulatory mechanisms are controlled by many different regulatory genes
Structural and regulatory genes
- A structural gene codes for a protein that has a function within a cell (e.g. enzymes, membrane carriers, hormones etc.)
- For example, the F8 gene codes for the protein Factor VIII involved in blood clotting
- Regulatory genes code for proteins (or various forms of RNA) that control the expression of structural genes