Chromatin is made up of DNA wound around histone proteins within the cell nucleus. It exists in a less condensed form, known as euchromatin, during interphase and a highly condensed form, known as heterochromatin, that is tightly packaged. Chromatin is organized into nucleosomes, which are further packaged into higher order structures like the 30nm fiber and solenoid to fully compact the DNA within a cell. This hierarchical packaging allows for the meters of DNA in a cell to fit within the nucleus.
Chromatin is the complex combination of DNA and proteins that makes up chromosomes. It can be made visible by staining with specific techniques and stain (thus the name chromatin which literally means colored material). The major proteins involved in chromatin are histone proteins; although many other chromosomal proteins have prominent roles too. The functions of chromatin is to package DNA into smaller volume to fit in the cell, to strengthen the DNA to allow mitosis and meiosis and to serve as a mechanism to control gene expression and DNA replication.
DNA is tightly packed in the nucleus of every cell. DNA wraps around special proteins called histones, which form loops of DNA called nucleosomes. These nucleosomes coil and stack together to form fibers called chromatin. Chromatin in turn forms larger loops and coils to form chromosomes.
DNA packaging is crucial because it makes sure that those excessive DNA are able to fit nicely in a cell that is many times smaller.
The DNA in bacterial cells are either circular or linear. To accommodate the size of bacterial cell, supercoiled DNA are folded into loops with each loop resembles shape of bead-like packets containing small basic proteins that is analogous to histone found in Eukaryotes.
Facts about DNA
Eukaryotic chromosomes
Chemical composition of eukaryotic chromosomes
Histones
Non-histone chromosomal protein
Scaffold proteins
Folded fibre model
Nucleosome model
H1 proteins
Histone modification
Chromatosome
Higher order of chromatin structure
Mechanism of DNA packaging
Conclusion
Chromatin is the complex combination of DNA and proteins that makes up chromosomes. It can be made visible by staining with specific techniques and stain (thus the name chromatin which literally means colored material). The major proteins involved in chromatin are histone proteins; although many other chromosomal proteins have prominent roles too. The functions of chromatin is to package DNA into smaller volume to fit in the cell, to strengthen the DNA to allow mitosis and meiosis and to serve as a mechanism to control gene expression and DNA replication.
DNA is tightly packed in the nucleus of every cell. DNA wraps around special proteins called histones, which form loops of DNA called nucleosomes. These nucleosomes coil and stack together to form fibers called chromatin. Chromatin in turn forms larger loops and coils to form chromosomes.
DNA packaging is crucial because it makes sure that those excessive DNA are able to fit nicely in a cell that is many times smaller.
The DNA in bacterial cells are either circular or linear. To accommodate the size of bacterial cell, supercoiled DNA are folded into loops with each loop resembles shape of bead-like packets containing small basic proteins that is analogous to histone found in Eukaryotes.
Facts about DNA
Eukaryotic chromosomes
Chemical composition of eukaryotic chromosomes
Histones
Non-histone chromosomal protein
Scaffold proteins
Folded fibre model
Nucleosome model
H1 proteins
Histone modification
Chromatosome
Higher order of chromatin structure
Mechanism of DNA packaging
Conclusion
Cot curve dispersed repeated DNA or interspersed repeated DNA tandem repeated DNA Long interspersed repeat sequences (LINEs) Short interspersed nuclear elements (SINEs) satellite, minisatellite and microsatellite DNA Variable Number Tandem Repeat (or VNTR)
Chromosome structure and packaging of dnaDIPTI NARWAL
Chromosome structure : classification based upon centromere position, autosomes and allosomes
Morphology of chromosome: chromatids, chromomeres, telomeres, sister chromatids
packaging of DNA: nucleosome model
functions of Chromosomes
Chromosomes are known as hereditary vehicles
They are formed of strands of DNA molecules which contain information for the development of different characteristics and performance of various metabolic activities of the cells
The coordination of various function is brought about through the formation of enzymes which are complex protein molecules
It is the DNA located in the mitochondria.Mitochondrial DNA (mtDNA or mDNA) is the DNA located in the mitochondria.
They are double stranded circular DNA molecule.
It is only 16 kb in length – contains 16,600 bp.
It is haploid in nature.
It codes for 37 genes.
13 genes provide instructions for making enzymes involved in oxidative phosphorylation.
It is a process that uses oxygen and simple sugars to create ATP, the cells main energy source.
This ppt explains the different forms of giant chromosomes, polytene and lamp brush chromosomes, its structure and functions. It helps the Genetics, Human genetics and molecular biology, Genetic engineering, Entomology students to learn about the giant chromosomes.
Cot curve dispersed repeated DNA or interspersed repeated DNA tandem repeated DNA Long interspersed repeat sequences (LINEs) Short interspersed nuclear elements (SINEs) satellite, minisatellite and microsatellite DNA Variable Number Tandem Repeat (or VNTR)
Chromosome structure and packaging of dnaDIPTI NARWAL
Chromosome structure : classification based upon centromere position, autosomes and allosomes
Morphology of chromosome: chromatids, chromomeres, telomeres, sister chromatids
packaging of DNA: nucleosome model
functions of Chromosomes
Chromosomes are known as hereditary vehicles
They are formed of strands of DNA molecules which contain information for the development of different characteristics and performance of various metabolic activities of the cells
The coordination of various function is brought about through the formation of enzymes which are complex protein molecules
It is the DNA located in the mitochondria.Mitochondrial DNA (mtDNA or mDNA) is the DNA located in the mitochondria.
They are double stranded circular DNA molecule.
It is only 16 kb in length – contains 16,600 bp.
It is haploid in nature.
It codes for 37 genes.
13 genes provide instructions for making enzymes involved in oxidative phosphorylation.
It is a process that uses oxygen and simple sugars to create ATP, the cells main energy source.
This ppt explains the different forms of giant chromosomes, polytene and lamp brush chromosomes, its structure and functions. It helps the Genetics, Human genetics and molecular biology, Genetic engineering, Entomology students to learn about the giant chromosomes.
A detail ppt about Genome organization with focus on all levels of organization. Most recent research and findings about CT is also added in this ppt. Detail account of 30nm fiber and its ultra structure and types is also included.
What is Genome ?
Types of Genome
Genetic Organization
Genome organization in prokaryotes
BACTERIAL GENOME
Importance of Plasmid
Packaging of DNA
Genome organization in eukaryotes
Chemical composition of chromatin
Nucleosome model
Prokaryotic Genome v/s Eukaryotic Genome
Very informative and basic concepts about laboratory precautions. This presentation shows how to work in laboratory. some people are not following these precaution and create the problem in laboratory work.
The genome assembly is simply the genome sequence produced after chromosomes have been fragmented, those fragments have been sequenced, and the resulting sequences have been put back together. Genome assembly has been metaphorically described as the process of assembling a jigsaw puzzle from the individual reads.
Genome assembly software (BySS, AMOS, Arapan-M, Arapan-S, Cortex, DNA Baser, DNAnexus etc.) combines the read into larger regions called contigs.
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.
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.
The Indian economy is classified into different sectors to simplify the analysis and understanding of economic activities. For Class 10, it's essential to grasp the sectors of the Indian economy, understand their characteristics, and recognize their importance. This guide will provide detailed notes on the Sectors of the Indian Economy Class 10, using specific long-tail keywords to enhance comprehension.
For more information, visit-www.vavaclasses.com
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.
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.
The Roman Empire A Historical Colossus.pdfkaushalkr1407
The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
Students, digital devices and success - Andreas Schleicher - 27 May 2024..pptxEduSkills OECD
Andreas Schleicher presents at the OECD webinar ‘Digital devices in schools: detrimental distraction or secret to success?’ on 27 May 2024. The presentation was based on findings from PISA 2022 results and the webinar helped launch the PISA in Focus ‘Managing screen time: How to protect and equip students against distraction’ https://www.oecd-ilibrary.org/education/managing-screen-time_7c225af4-en and the OECD Education Policy Perspective ‘Students, digital devices and success’ can be found here - https://oe.cd/il/5yV
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
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.
2. o Cells contain a nucleus surrounded by a nuclear membrane in eukaryotic cells,
and a nuclear region in the prokaryotic cells.
o In a non-dividing cell the nucleus is filled with a thread-like material known as
"chromatin".
o Chromatin is made up of DNA and proteins (mainly histones and some non-
histone acidic proteins).
o The chromosomes themselves are macromolecular entities that must be
synthesized, packaged, protected, and properly distributed to daughter cells at
cell division.
3. • The packaging of tremendous amount of genetic information into the small space
within a cell has been called the ultimate storage problem.
• Chromosomal DNA exist in the form of very long molecules, which must be
tightly packed to fit into the small confines of a cell.
• The structure of DNA can be considered at three hierarchical levels:
a. The primary structure of DNA is its nucleotide sequence
b. The secondary structure is the double stranded helix
c. The tertiary structure refers to higher order folding that allow DNA to be
packed into the confined space of a cell.
4. • One type of DNA tertiary structure is supercoiling which takes place when the
DNA helix is subjected to strain by being over wound or under wound.
• Energy is used to add or remove any turns, strains is placed on the molecule,
causing the helix to super coil, or twist on itself.
• Molecule that are over rotated exhibit positive supercoiling.
• Under rotated molecules exhibit negative supercoiling.
• Supercoiling is a partial solution to the cells DNA packing problem because
super coiled DNA occupies less space than relaxed DNA.
5.
6. • Supercoiling relies on topoisomerases enzymes that add or remove rotation
from the DNA helix by temporarly breaking the nucleotide strand, rotating the
ends around each other, the rejoining the broken ends.
• Overrotation or underrotation of a DNA double helix places strain on the
molecule, causing it to supercoil.
• Supercoiling is controled by topoisomerase enzymes.
• Most cellular DNA is negetively supercoiled, which eases the seperation of
nucleotide strands during replication and transcription and allow DNA to be
packed into small spaces.
7. • Individual eukaryotic chromosome
contain enormous amounts of DNA.
• Chromosome are in an elongated
relatively uncondensed state during
interphase of the cell cycle.
p
q
8. • Walther Flemming first used the term Chromatin in 1882. At that time, Flemming
assumed that within the nucleus there was some kind of a nuclear-scaffold.
• Chromatin, which consists of DNA complexed to proteins, is the material that
makes up eukaryotic chromosomes.
• The most abundant of these proteins are the five types of positively charged
histone proteins H1, H2A, H2B, H3, and H4.
• Variant histones may at times be incorporated into chromatin in place of the
normal histones.
• In non-dividing cells there are two types of chromatin: euchromatin and
heterochromatin.
9. Electron micrographs of “chromatin” preparations
• Two classes of chromatin proteins:
a. Histones (core Histones H2A, H2B, H3, H4)
b. Non- histone proteins
11. • The histone octamer and associated DNA that form the nucleosome combine
with histone H1 to form the chromatosome.
• The addition of H1 to a nucleosome results in protection of an additional 20 to
22 bp of linker DNA adjacent to the nucleosome, and thus H1 is often referred
to as the linker histone.
• Only one H1 subunit is present per chromatosome, unlike the core histones,
which are present in two copies each.
• DNA binding in H1 is intrinsic to the central globular region, which contains
two DNA-binding sites.
• H1 binds only one of the linker DNA strands, and the second DNA site in
histone H1 binds to the central region of the DNA supercoil in the nucleosome
12. • Histones are rich in the basic amino acids arginine and lysine, which together make up
about 25% of the amino acid residues in any given histone protein.
• Histone proteins are highly conserved among eukaryotic cells.
• Histones H3 and H4 are nearly identical in all eukaryotes, suggesting strict conservation of
their functions.
• Histones H1, H2A, and H2B show less sequence similarity, but on the whole, they are
more conserved than other types of proteins.
• Salt bridges between positively charged histones and negatively charges DNA play a major
role in stabilizing DNA-histone complex.
13. o H1, H2A & H2B, are rich in lysine whereas H3 & H4 are arginine rich H1 is
highly unconserved and mutable H3 & H4 are highly conserved molecules.
o According to molecular weight the relation is H1 > H3 >H2A >H2B >H4.
o Histones proteins lack Tryptophan amino acid.
o Histones octamer has a structural core of an H3.H4 tetramer associated with two
H2A.H2B dimmers.
o Each Histones is extensively interdigitated with its partner.
o All core Histones have the structural motif of the Histones fold.
o The Histones N-terminal tails extend out of the nucleosome.
15. • In chromatin, those protein which remain after the histone have been
removed as classified as non histone protein .
• Scaffold proteins, DNA polymerase, heterochromatin protein 1 and paycomb
are common non histone .
• Non-histone protein Higher molecular weight - Approximately 1.0 to 1.5
lakh dalton Acidic in nature Mostly act as enzyme Promotes gene action.
16. o DNA is roughly 3 meter long and it has to be packed in nucleus which is few
micrometres in diameter, hence higher order of packaging is required.
o There are various order of packaging
a. First order of packaging – Nucleosome
b. Second order of packaging – Solenoid fibre
c. Scaffold loop Chromatids Chromosome are third order of packaging.
17.
18. The nucleosome is basic repeating unit of
chromatin.
It provides the lowest level of compaction
of double-strand DNA into the cell
nucleus.
It often associates with transcription.
1974: Roger Kornberg discovers
nucleosome who won Nobel Prize in
2006.
19. • The nucleosome consists of a core particle of eight histone proteins and DNA
that wraps around the core.
• Chromatosome, which are nucleosomes bound to an H1 histone, are separated
by linker DNA.
• Nucleosmes fold to form a 30-nm chromatin fiber, which appears as a series
of loops that pack to create a 250 nm wide fiber.
• Helical coiling of the 250 nm fiber produces a chromatid.
20. • Solenoid is known as Second level of packaging .
• Solenoid – Second level of packaging Proposed by Finch & Klug 6 nucleosome
together forms Solenoid Diameter is 30 nm H1 histone stabilizes the Structure.
21. o Super Solenoid : Super Solenoid The final level of packaging is
characterized by the 700 nm structure seen in the metaphase Chromosome
known as super solenoid structure.
o The condensed piece of chromatin has a characteristic scaffolding structure
that can be detected in metaphase chromosomes.
o This appears to be the result of extensive looping of the DNA in the
chromosome.
22.
23. Compaction level of interphase chromosomes is not
uniform
Euchromatin
a. Less condensed regions of chromosomes
b. Transcriptionally active
c. Regions where 30 nm fiber forms radial loop domains
Heterochromatin
a. Tightly compacted regions of chromosomes
b. Transcriptionally inactive (in general)
c. Radial loop domains compacted even further