Gene expression is the process by which the information from a gene is used in the synthesis of a functional gene product. It involves two main stages - transcription of DNA to mRNA and translation of mRNA to protein. In eukaryotes, gene expression requires several processing steps between transcription and translation including 5' capping, splicing, and 3' polyadenylation of mRNA. Protein synthesis occurs via three phases - initiation, elongation, and termination on ribosomes in the cytoplasm. Gene expression is regulated at multiple levels including transcription, RNA processing, translation and post-translation.
Prokaryotic and eukaryotic transcription with their clinical applicationsrohini sane
A comprehensive presentation on Prokaryotic and Eukaryotic DNA transcription with their clinical applications for Medical, dental, Pharma & Biotechnology students to facilitate self- study.
it describes transcription with simple diagram and animation. its steps and inhibitors are described for both eukaryotes and prokaryotes. it will be easily understood by UG students . post transcriptional modification of all the RNA are also described with diagrams.
Prokaryotic and eukaryotic transcription with their clinical applicationsrohini sane
A comprehensive presentation on Prokaryotic and Eukaryotic DNA transcription with their clinical applications for Medical, dental, Pharma & Biotechnology students to facilitate self- study.
it describes transcription with simple diagram and animation. its steps and inhibitors are described for both eukaryotes and prokaryotes. it will be easily understood by UG students . post transcriptional modification of all the RNA are also described with diagrams.
This presentation is about the transcription machinery that is required for the transcription in eukaryotes. The comparison between the transcription factors involved in prokaryotes and eukaryotes. The initiation of transcription and how it helps in producing a mRNA.
DNA as a Genetic Material - Dr. P. Saranraj, Assistant Professor, Department of Microbiology, Sacred Heart College (Autonomous), Tirupattur, Vellore District, Tamil Nadu, India.
Gene regulation in eukaryotes in a nutshell covering all the important stages of gene regulation in eukaryotes at transcriptional level, translation level and post-translational level.
RNA TRANSCRIPTION AND PROCESSING, DISORDERS OF ABNORMAL POST TRANSLATIONAL MODIFICATION, DRUGS EXPLOITING EUKARYOTIC PROKARYOTIC POST TRANSLATIONAL MODIFICATION
This presentation is about the transcription machinery that is required for the transcription in eukaryotes. The comparison between the transcription factors involved in prokaryotes and eukaryotes. The initiation of transcription and how it helps in producing a mRNA.
DNA as a Genetic Material - Dr. P. Saranraj, Assistant Professor, Department of Microbiology, Sacred Heart College (Autonomous), Tirupattur, Vellore District, Tamil Nadu, India.
Gene regulation in eukaryotes in a nutshell covering all the important stages of gene regulation in eukaryotes at transcriptional level, translation level and post-translational level.
RNA TRANSCRIPTION AND PROCESSING, DISORDERS OF ABNORMAL POST TRANSLATIONAL MODIFICATION, DRUGS EXPLOITING EUKARYOTIC PROKARYOTIC POST TRANSLATIONAL MODIFICATION
Microarray as one of recent biomedical technologies produce high dimensional data. This makes statistical analysis become challenging. I presented an overview of microarray analysis specifically in the use of gene expression profiling in a discussion.
Khaled El Masry, is an assistant Lecturer of Human Anatomy & Embryology, Mansoura University, Egypt. Great thanks to Prof. Dr Salwa Gawish, professor of Cytology & Histology, Mansoura University, for her great effort in explaining Genetics course.
Regulation of gene expression in eukaryotesAnna Purna
Presence of nucleus and complexity of eukaryotic organism demands a well controlled gene regulation in eukaryotic cell. Tissue specific gene expression is essential as they are multicellular organisms in which different cells perform different functions. This PPT deals with various control points for the gene regulation and expression within a cell.
This is a mini-research work presented in partial fulfilment of the requirements for the award of a masters degree in Biochemistry, University of Ibadan.
INTRODUCTION
HISTORY
MECHANISM OF PROTEIN SYNTHESIS
TRANSCRIPTION
TRANSLATION
TRANSCRIPTION
INITIATION
ELONGATION
TERMINATION
TRANSLATION
AMINOACYLATION OF tRNA
INITIATION OF POLYPEPTIDE CHAIN
ELONGATION
TERMINATION
CONCLUSION
REFERENCES
Protein synthesis and processing: Ribosome, formation of initiation complex, initiation factors and their regulation, elongation and elongation factors, termination, genetic code, aminoacylation of tRNA, tRNA-identity, aminoacyl tRNA synthetase, and translational proof-reading, translational inhibitors, Post Translational modification of proteins. Protein targeting.
DNA- Transcription and Tranlation, RNA, Ribosomes and membrane proteins.pptxLaibaSaher
Detailed presentation on the topic of DNA, transcription and translation, RNA, Ribosomes and Membrane proteins. Along with their structure and functions. Detailed Diagram and complete description of the processes. Along with references and Gifs that makes the presentation look more creative.
How to Split Bills in the Odoo 17 POS ModuleCeline George
Bills have a main role in point of sale procedure. It will help to track sales, handling payments and giving receipts to customers. Bill splitting also has an important role in POS. For example, If some friends come together for dinner and if they want to divide the bill then it is possible by POS bill splitting. This slide will show how to split bills in odoo 17 POS.
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
Instructions for Submissions thorugh G- Classroom.pptxJheel Barad
This presentation provides a briefing on how to upload submissions and documents in Google Classroom. It was prepared as part of an orientation for new Sainik School in-service teacher trainees. As a training officer, my goal is to ensure that you are comfortable and proficient with this essential tool for managing assignments and fostering student engagement.
Welcome to TechSoup New Member Orientation and Q&A (May 2024).pdfTechSoup
In this webinar you will learn how your organization can access TechSoup's wide variety of product discount and donation programs. From hardware to software, we'll give you a tour of the tools available to help your nonprofit with productivity, collaboration, financial management, donor tracking, security, and more.
Synthetic Fiber Construction in lab .pptxPavel ( NSTU)
Synthetic fiber production is a fascinating and complex field that blends chemistry, engineering, and environmental science. By understanding these aspects, students can gain a comprehensive view of synthetic fiber production, its impact on society and the environment, and the potential for future innovations. Synthetic fibers play a crucial role in modern society, impacting various aspects of daily life, industry, and the environment. ynthetic fibers are integral to modern life, offering a range of benefits from cost-effectiveness and versatility to innovative applications and performance characteristics. While they pose environmental challenges, ongoing research and development aim to create more sustainable and eco-friendly alternatives. Understanding the importance of synthetic fibers helps in appreciating their role in the economy, industry, and daily life, while also emphasizing the need for sustainable practices and innovation.
How to Create Map Views in the Odoo 17 ERPCeline George
The map views are useful for providing a geographical representation of data. They allow users to visualize and analyze the data in a more intuitive manner.
We all have good and bad thoughts from time to time and situation to situation. We are bombarded daily with spiraling thoughts(both negative and positive) creating all-consuming feel , making us difficult to manage with associated suffering. Good thoughts are like our Mob Signal (Positive thought) amidst noise(negative thought) in the atmosphere. Negative thoughts like noise outweigh positive thoughts. These thoughts often create unwanted confusion, trouble, stress and frustration in our mind as well as chaos in our physical world. Negative thoughts are also known as “distorted thinking”.
Palestine last event orientationfvgnh .pptxRaedMohamed3
An EFL lesson about the current events in Palestine. It is intended to be for intermediate students who wish to increase their listening skills through a short lesson in power point.
This is a presentation by Dada Robert in a Your Skill Boost masterclass organised by the Excellence Foundation for South Sudan (EFSS) on Saturday, the 25th and Sunday, the 26th of May 2024.
He discussed the concept of quality improvement, emphasizing its applicability to various aspects of life, including personal, project, and program improvements. He defined quality as doing the right thing at the right time in the right way to achieve the best possible results and discussed the concept of the "gap" between what we know and what we do, and how this gap represents the areas we need to improve. He explained the scientific approach to quality improvement, which involves systematic performance analysis, testing and learning, and implementing change ideas. He also highlighted the importance of client focus and a team approach to quality improvement.
2. Gene Expression
The process by which a gene's information is
converted into the structures and functions of a cell
by a process of producing a biologically functional
molecule of either protein or RNA (gene product) is
made.
Gene expression is assumed to be controlled at
various points in the sequence leading to protein
synthesis.
2
3. Gene Structure
Eukaryotic gene structure: Most eukaryotic genes in
contrast to typical bacterial genes, the coding
sequences (exons) are interrupted by noncoding DNA
(introns). The gene must have (Exon; start signals;
stop signals; regulatory control elements).
The average gene 7-10 exons spread over 10-16kb of
DNA.
3
7. Gene Expression
Transcription
Synthesis of an RNA that is complementary to one of
the strands of DNA.
Translation
Ribosomes read a messenger RNA and make protein
according to its instruction.
7
10. Transcription Enzymes
RNA polymerase: The enzyme that controls
transcription and is characterized by:
Search DNA for initiation site,
It unwinds a short stretch of double helical DNA to
produce a single-stranded DNA template,
It selects the correct ribonucleotide and catalyzes the
formation of a phosphodiester bond,
It detects termination signals where transcript ends.
10
11. Eukaryotic RNA polymerases have different roles in transcription
Polymerase I nucleolus Makes a large precursor to the
major rRNA (5.8S,18S and 28S
rRNA in vertebrates
Polymerase II nucleoplasm Synthesizes hnRNAs, which
are precursors to mRNAs. It
also make most small nuclear
RNAs (snRNAs
Polymerase III Nucleoplasm Makes the precursor to
5SrRNA, the tRNAs and
several other small cellular
and viral RNAs.
12. Eukaryotic Promoter
Conserved eukaryotic promoter elements Consensus sequence
CAAT box GGCCAATCT
TATA box TATAA
GC box GGGCGG
CAP site TAC
12
Eukaryotic Promoter lies upstream of the gene.
There are several different types of promoter found
in human genome, with different structure and
different regulatory properties class/I/II/III.
13. Transcription Factors
Transcription factors are proteins that bind to
DNA near the start of transcription of a gene.
Transcription factors either inhibit or assist
RNA polymerase in initiation and maintenance
of transcription.
13
15. Enhancers
Enhancers are stretches of bases within DNA, about 50
to 150 base pairs in length; the activities of many
promoters are greatly increased by enhancers which
can exert their stimulatory actions over distances of
several thousands base pairs.
15
16. Preinitiation Complex
The general transcription factors combine with RNA
polymerase to form a pre-initiation complex that is
competent to initiate transcription as soon as nucleotides
are available.
The assembly of the pre-initiation complex on each kind
of eukaryotic promoter (class II promoters recognized by
RNA polymerase II) begins with the binding of an
assembly factor to the promoter.
16
19. Initiation
The polymerase binding causes the unwinding of the
DNA double helix which expose at least 12 bases on
the template.
This is followed by initiation of RNA synthesis at this
starting point.
19
20. Initiation
The RNA polymerase starts building the RNA chain;
it assembles ribonucleotides triphosphates: ATP;
GTP; CTP and UTP into a strand of RNA.
After the first nucleotide is in place, the polymerase
joins a second nucleotide to the first, forming the
initial phosphodiester bond in the RNA chain.
20
21. Elongation
RNA polymerase directs the sequential binding of
riboncleotides to the growing RNA chain in the 5' - 3'
direction.
Each ribonucleotide is inserted into the growing RNA strand
following the rules of base pairing. This process is repeated
utill the desired RNA length is
synthesized……………………..
21
22. Termination
Terminators at the end of genes; signal termination.
These work in conjunction with RNA polymerase to
loosen the association between RNA product and
DNA template. The result is that the RNA dissociate
from RNA polymerase and DNA and so stop
transcription.
The product is immature RNA or pre mRNA (Primary
transcript).
22
23. The primary product of RNA transcription; the
hnRNAs contain both intronic and exonic sequences.
These hnRNAs are processed in the nucleus to give
mature mRNAs that are transported to the cytoplasm
where to participate in protein synthesis.
23
26. RNA Processing
Capping
The cap structure is added to the 5' of the newly
transcribed mRNA precursor in the nucleus prior
to processing and subsequent transport of the
mRNA molecule to the cytoplasm.
Splicing:
Step by step removal of pre mRNA and joining of
remaining exons; it takes place on a special
structure called spliceosomes.
26
27. RNA Processing
Addition of poly A tail:
Synthesis of the poly (A) tail involves cleavage of
its 3' end and then the addition of about 40- 200
adenine residues to form a poly (A) tail.
27
29. Alternative Splicing
Alternative splicing: is a very common phenomenon
in higher eukaryotes. It is a way to get more than one
protein product out of the same gene and a way to
control gene expression in cells.
29
31. The Genetic Code
The sequence of codons in the mRNA defines
the primary structure of the final protein.
Three nucleotides in mRNA (a codon)specify
one amino acid in a protein.
31
33. The Genetic Code
The triplet sequence of mRNA that specify certain
amino acid.
64 different combination of bases; 61 of them code for
20 amino acids (AA); the last three codon
(UAG,UGA,UAA) do not code for amino acids; they
are termination codons.
Degenerate
More than one triplet codon specify the same amino
acid.
33
34. The Genetic Code
Unambiguous
Each codon specifies a particular amino acid, the
codon ACG codes for the amino acid threonine,
and only threonine.
Non overlapping
This means that successive triplets are read in
order. Each nucleotide is part of only one triplet
codon.
34
37. Translation
Translation is the process by which ribosomes read
the genetic message in the mRNA and produce a
protein product according to the message's
instruction.
37
39. Ribosomes
Eukaryotic ribosomes are larger. They consist of two
subunits, which come together to form an 80S
particle;
60S subunit holds (three rRNAs 5S, 5.8S, 28S and
about 40 proteins).
40S subunit contains (an18S rRNA and about 30
proteins).
39
40. The large ribosomal subunit contains three tRNA
binding sites, designated A, P, and E.
The A site binds an aminoacyl-tRNA (a tRNA bound
to an amino acid);
P site binds a peptidyl-tRNA (a tRNA bound to the
peptide being synthesized).
The E site binds a free tRNA before it exits the
ribosome.
40
41. Preparatory Steps for Protein Synthesis
First, aminoacyl tRNA synthetase joins amino acid to
their specific tRNA.
Second, ribosomes must dissociate into subunits at
the end of each round of translation.
41
42. The protein synthesis occur in 3 phases
Accurate and efficient initiation occurs; the
ribosomes binds to the mRNA, and the first amino
acid attached to its tRNA.
Chain elongation, the ribosomes adds one amino acid
at a time to the growing polypeptide chain.
Accurate and efficient termination, the ribosomes
releases the mRNA and the polypeptide.
42
43. Initiation
The initiation phase of protein synthesis requires over
10 eukaryotic Initiation Factors (eIFs): Factors are
needed to recognize the cap at the 5'end of an mRNA
and binding to the 40s ribosomal subunit.
Binding the initiator Met-tRNAiMet (methionyl-
tRNA) to the 40S small subunit of the ribosome.
43
44. Initiation
Scanning to find the start codon by binding to the
5'cap of the mRNA and scanning downstream until they
find the first AUG (initiation codon).
The start codon must be located and positioned
correctly in the P site of the ribosome, and the initiator
tRNA must be positioned correctly in the same site.
Once the mRNA and initiator tRNA are correctly
bound, the 60S large subunit binds to form 80s initiation
complex with a release of the eIF factors.
44
45. Elongation
Transfer of proper aminoacyl-tRNA from
cytoplasm to A-site of ribosome;
Peptide bond formation; Peptidyl transferase forms
a peptide bond between the amino acid in the P site, and
the newly arrived aminoacyl tRNA in the A site. This
lengthens the peptide by one amino acids.
45
46. Elongation
Translocation; translocation of the new peptidyl t-
RNA with its mRNA codon in the A site into the free P
site occurs. Now the A site is free for another cycle of
aminoacyl t-RNA codon recognition and elongation.
Each translocation event moves mRNA, one codon
length through the ribosomes.
46
47. Termination
Translation termination requires specific protein
factors identified as releasing factors, RFs in E. coli and
eRFs in eukaryotes.
The signals for termination are the same in both
prokaryotes and eukaryotes. These signals are
termination codons present in the mRNA. There are 3
termination codons, UAG, UAA and UGA.
47
48. Termination
After multiple cycles of elongation and polymerization
of specific amino acids into protein molecules, a
nonsense codon = termination codon of mRNA appears
in the A site. The is recognized as a terminal signal by
eukaryotic releasing factors (eRF) which cause the
release of the newly synthesized protein from the
ribosomal complex.
48
49. Polysomes
Most mRNA are translated by more than one
ribosome at a time; the result, a structure in which
many ribosomes translate a mRNA in tandem, is
called a polysomes.
49
50. Control of Gene Expression
Transcriptional
Posttranscriptional
Translational
Posttranslational
50
52. Control of gene expression depends various factors
including:
Chromosomal activation or deactivation.
Control of initiation of transcription.
Processing of RNA (e.g. splicing).
Control of RNA transport.
Control of mRNA degradation.
Control of initiation of translation (only in
eukaryotes).
Post-translational modifications.
52
55. Eukaryotic Gene Expression
Essentially all humans' genes contain introns. A
notable exception is the histone genes which are
intronless.
Eukaryote genes are not grouped in operons. Each
eukaryote gene is transcribed separately, with
separate transcriptional controls on each gene.
Eukaryotic mRNA is modified through RNA splicing.
Eukaryotic mRNA is generally monogenic
(monocistronic); code for only one polypeptide.
55
56. Eukaryotic Gene Expression
Eukaryotic mRNA contain no Shine-Dalgarno
sequence to show the ribosomes where to start
translating. Instead, most eukaryotic mRNA have
caps at their 5` end which directs initiation factors to
bind and begin searching for an initiation codon.
Eukaryotes have a separate RNA polymerase for each
type of RNA.
In eukaryotes, polysomes are found in the cytoplasm.
Eukaryotic protein synthesis initiation begins with
methionine not N formyl- methionine. 56
57. Prokaryotic vs. Eukaryotic
Bacterial genetics are different.
Prokaryote genes are grouped in operons.
Prokaryotes have one type of RNA polymerase for all
types of RNA,
mRNA is not modified
The existence of introns in prokaryotes is extremely
rare.
57
58. Prokaryotic vs. Eukaryotic
To initiate transcription in bacteria, sigma factors bind
to RNA polymerases. RNA polymerases/ sigma factors
complex can then bind to promoter about 40
deoxyribonucleotide bases prior to the coding region of
the gene.
In prokaryotes, the newly synthesized mRNA is
polycistronic (polygenic) (code for more than one
polypeptide chain).
In prokaryotes, transcription of a gene and translation
of the resulting mRNA occur simultaneously. So many
polysomes are found associated with an active gene.
58