Proto genes are the ones that code for normal cell growth and once a mutation occurs in these type of genes they turn into oncogenes where they produce more proteins than normal and become cancerous. Though cancer can also be a result of a decreased function of genes that inhibit cell division.
What’s the difference between a repressible and inducible operon?
Repressible operons are typically turned on typically building some type of molecule but when enough of that molecule is produced it binds to the repressor activating which then binds to the activation site and block the production of that molecule until the concentration goes down again. Example would be the lac operon. Inducible operons are typically off but the production of a certain other molecule (inducer) will bind to the repressor deactivating allowing the activation site to be open and the production of whatever this gene makes which would typically be something used to break down a molecule. An example of this would be the tryp operon.
What is DNA methylation and histone acetylation and what is the function for the cell?
DNA methylation makes a chromosome more tightly packed because it makes the DNA more attracted to itself therefore limiting gene expression. Histone acetylation is when amino groups are added to histone proteins decreasing the attraction and making them unwind more. Genes in an area like this are more likely to be expressed. The mechanisms of cell specializing utilize these two types of increased or decreased expression.
Facts:
- Cell differentiation is how cells go from being blank in the zygote to being specialized to take on specific functions in the organism
- Morphogenesis is how cells organize into things like tissues and organs
- Apoptosis is the programmed suicide of a cell that occurs once DNA is too damaged
- The P53 gene is an important tumor-suppressor meaning that it prevents cancer by regulating the cell cycle
- The operon has the operator, promoter, and the genes of the operator all within it
This shows how through alternate splicing the same gene can give rise to several different codons and therefore proteins. In this way gene expression can help to preserve space within the genome by using one gene for several uses by just expressing it different ways.
Summary:
Operons are used so that cells don’t use their energy making molecules they don’t need at that exact moment. These can be either up repressible inducible operons and they are like off and on switches for a particular gene. Gene expression is regulated from the time a cell is in the zygote well into its developed life through methods such as alternate splicing, mRna degradation, chromatin modification, and protein processing. The use of many non-coding RNA molecules is to help with gene expression. Cells differentiate so that only certain genes this is the reason that liver cells and skin cells are not the same they different regulations of gene expression aid with this.
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