Eukaryotic gene
This presentation is the property of its rightful owner.
Sponsored Links
1 / 26

EUKARYOTIC GENE PowerPoint PPT Presentation


  • 61 Views
  • Uploaded on
  • Presentation posted in: General

EUKARYOTIC GENE. BAHAY GÜLLE* FATIH UNIVERSITY ART & SCIENCE FACULTY BIOLOGY DEPARTMANT 4 TH YEAR STUDENT. Eukaryotes have a complex intracellular organization with internal membranes, membrane bond-organelles, a nucleus and a welled organized cytoskeleton.

Download Presentation

EUKARYOTIC GENE

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Eukaryotic gene

EUKARYOTIC GENE

BAHAY GÜLLE*

FATIH UNIVERSITY ART & SCIENCE FACULTY BIOLOGY DEPARTMANT 4TH YEAR STUDENT


Eukaryotic gene

Eukaryotes have a complex intracellular organization with internal membranes, membrane bond-organelles, a nucleus and a welled organized cytoskeleton.


Eukaryotic gene

Eukaryotic cells have several linear chromosomes in their nuclei . In each of the chromosomes there is a very long DNA molecule packaged by histones and other proteins.


Eukaryotic gene

The number and DNA content of chromosomes are different among different species.

Human genome : 3x109 nts

Onion : 15x109 nts

Lily : 90x109 nts


Prokaryotic vs eukaryotic genes

Eukaryotes

large genomes

low gene density

introns (splicing)

RNA processing

heterogeneous promoters

polyadenylation

Prokaryotes

small genomes

high gene density

no introns (or splicing)

no RNA processing

similar promoters

overlapping genes

Prokaryotic vs. Eukaryotic Genes


Genome size

Genome Size

Eukaryotic genomes may be so large, in part, because most eukaryotic genes in higher eukaryotic organisms are interrupted by introns.


Eukaryotic gene

The main proportion of DNA in the genomes are non-coding sequences, thus gen density is low in eukaryotic genomes.(The total number of gene in human is estimated to be 30,000-40,000


Eukaryotic gene

Most eukaryotic genes are DNA sequences that are never translated into polypeptides. These noncoding regions, called introns, alternate with regions called exons that are expressed in the polypeptide sequence.


Protein coding genes have

Protein-coding genes have

  • exons whose sequence encodes the polypeptide;

  • introns that will be removed from the mRNA before it is translated;

  • a transcription start site

  • a promoter

    -the basal or core promoter located within about 40 bp of the start site

    -an "upstream" promoter, which may extend over as many as 200 bp farther upstream


Eukaryotic gene

The transcription start is usually associated with an AT rich DNA sequence about 25 bp away from the initiation - the TATA box

Upstream anywhere from 50 to 100 bases from the TATA box is another sequence associated with transcription initiation - the CAAT box. This sequence may not be necessary in all genes.


Eukaryotic gene

Eukaryotic Gene ControlEukaryotic control sites include promoter consensus sequences similar to those in bacteria.


Eukaryotic gene

In eukaryotes the splicing process of a pre-mRNA can lead to different ripe mRNA molecules and therefore to different proteins. This phenomenon is called alternative splicing.


Eukaryotic gene

When the pre-mRNA has been transcribed from the DNA, it includes several introns and exons. But what is an intron and what is an exon is not decided yet. This decision is made during the splicing process.


F or eukaryotes it was a very important step towards higher efficiency

For eukaryotes it was a very important step towards higher efficiency.

  • The information can be stored much more economically.

  • New proteins can evolve much faster than in prokaryotes.

  • Therefore the adaptation to new environments can be much faster - with fewer generations - than in prokaryotes.


Thanks

THANKS.....


  • Login