This document discusses the regulation of prokaryotic gene expression. It begins by defining genes and gene expression. It then explains the two main types of gene regulation: positive regulation, which increases gene expression through activator proteins, and negative regulation, which decreases expression through repressor proteins. An example of positive and negative regulation is shown in a figure. The document goes on to explain that in prokaryotes, genes involved in metabolic pathways are often arranged in operons, where multiple genes are transcribed together from a single promoter. Two specific operons are discussed in more detail: the tryptophan operon in E. coli, which is repressible, and the lac operon, which is induced by lactose

1. PRESENTED BY
ADITI TRIPATHI
B.TECH BIOTECHNOLOGY
18141029005
REGULATION OF
PROKARYOTIC GENE
EXPRESSION

2. GENES
 Genes are subunits of
DNA, the data database
of a cell that is contained
inside the cell core.
 This DNA conveys the
hereditary diagram that is
utilized to make all the
proteins the cell needs.
 Each quality contains a
specific arrangement of
directions that code for a
particular protein.

3. GENE EXPRESSION
 Gene Expression is the
procedure by which the
data encoded in a
quality is utilized to
coordinate the gathering
of a protein atom.
 Gene Expression is
investigated through an
investigation of protein
structure and capacity,
interpretation and
interpretation, separation
and immature
microorganisms.

4. REGULATION OF GENE
EXPRESSION

5. TYPES OF REGULATION OF GENE
POSITIVE
REGULATION
 When the declaration of
hereditary data is
quantitatively expanded
by the nearness of explicit
administrative component
is known as positive
regulation.
 Element modulating
positive regulation is
known as activator or
positive regulator.
NEGATIVE
REGULATION
 When the statement of
hereditary data is reduced
by the nearness of explicit
administrative component
is known as negative
expression.
 element or molecule
mediating the negative
regulation is said to be
repressor.

6. Fig. Positive and Negative Gene Regulation

7. PROKARYOTIC GENE
REGULATION
 Prokaryotes provide models
for the study of gene
expression in mammalian
cells. Some features of
prokaryotes gene expression
are unique. In prokaryotes,
genes involved in metabolic
pathway are often present in
linear array called as operon.
 mRNA are polycistronic.
 Multiple genes are present on
single transcript and a single
promoter initiates the
transcription all genes.

8. In genetics, an operon is a functional unit of genomic
DNA containing a cluster of genes under the control of
a single promoter.
Operons occur primarily in prokaryotes but also in
some eukaryotes.
Operons are related to regulons, stimulons and
modulons.
An operon is made up of several structural genes
arranged under a common promoter and regulated by a
common operator.
It is defined as a set of adjacent structural genes, plus
the adjacent regulatory signals that affect transcription
of the structural genes.
OPERON

9. ACTIVITY OF OPERON

10. TRYPTOPHAN OPERON
 Discovered in 1953 by Jacques Monod and
colleagues, the trp operon in E. coli was the first
repressible operon to be discovered.
 This operon contains five structural genes
 trp E,
 trp D,
 trp C,
 trp B, and
 trp A, which encodes tryptophan synthetase.
 It also contains a promoter which binds to RNA
polymerase and an operator which blocks
transcription when bound to the protein synthesized
by the repressor gene (trp R) that binds to the
operator.

11. LAC OPERON

12. ACTIVITY OF LAC
OPERON

13. THE END
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