2. Definition
Gene regulation is the process of turning genes on
and off.
During early development, cells begin to take on
specific functions.
Gene regulation ensures that the appropriate
genes are expressed at the proper times
It is the process that control the rate and
manner of gene expression
3. Gene expression is the process by which
information from a gene is used in the synthesis of
a functional gene product.
These products are often proteins, but in non-
protein coding genes such as transfer RNA (tRNA)
or small nuclear RNA (snRNA) genes, the product
is a functional RNA.
Gene expression
4. How genes are expressed
The process of gene
expression involves two main
stages:
Transcription: the production
of messenger RNA (mRNA) by
the enzyme RNA polymerase,
and the processing of the
resulting mRNA molecule.
Translation: the use of mRNA
to direct protein synthesis
5. Gene control regions
A promoter. A region a few hundred nucleotides 'upstream' of
the gene (toward the 5' end).
It is not transcribed into mRNA, but plays a role in controlling
the transcription of the gene.
Transcription factors bind to the promoter region and assist in
the binding of RNA polymerases.
Enhancers. Some transcription factors (called activators)
bind to regions called 'enhancers' that increase the rate of
transcription
Silencers. Some transcription factors (called repressors)
bind to regions called 'silencers' that depress the rate of
transcription.
6. Types of gene regulation
Gene regulation can be negative or positive
. In negative regulation, a repressor molecule
binds to the sliencer and terminates transcription.
In positive regulation, an activator interacts with
the RNA polymerase in the promoter region to
initiate transcription.
7. Necessity of Gene Regulation
Unicellular organisms
Depending on the needs of the body some genes have
to be transcribed whereas the rest have to be switched
off
Helps to adapt to the changes in environment
Multicellular organisms
Helps in differentiation of cells
Performance of various functions in the body
