The cell cycle is regulated by cyclins and cyclin-dependent kinases (Cdks). Cyclins activate Cdks to phosphorylate proteins and trigger transitions between phases such as G1 to S and G2 to M. Checkpoints ensure completion of earlier steps before progression. The levels of cyclins and activity of Cdks are regulated by other proteins in response to internal signals, like DNA replication status, and external signals, like growth factors, to control the cell cycle.
Basic Cell cycle regulation suitable for undergraduate students.
This presentation has been started from the basics to enable easy understanding. It covers all the details of cell cycle regulation in yeast as well as higher 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
This slide describes the various stages of the Eukaryotic cell cycle. The diagrams included here explains the various changes that take place during the mitotic division of a eukaryotic cell.
The delivery of newly synthesized protein to their proper cellular destination, usually referred to as protein targeting or sorting.
The mode of protein transport depends chiefly on the location in the cell cytoplasm of the polysomes involved in protein synthesis.
There are two modes of protein sorting:-
1) Co - translational Transportation.
2) Post - translational Transportation.
Basic Cell cycle regulation suitable for undergraduate students.
This presentation has been started from the basics to enable easy understanding. It covers all the details of cell cycle regulation in yeast as well as higher 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
This slide describes the various stages of the Eukaryotic cell cycle. The diagrams included here explains the various changes that take place during the mitotic division of a eukaryotic cell.
The delivery of newly synthesized protein to their proper cellular destination, usually referred to as protein targeting or sorting.
The mode of protein transport depends chiefly on the location in the cell cytoplasm of the polysomes involved in protein synthesis.
There are two modes of protein sorting:-
1) Co - translational Transportation.
2) Post - translational Transportation.
This presentation on "Cell Cycle regulation" takes you to the cell cycle describing the stages and checkpoints involved providing some of the evidences of cell cycle regulation. Then we will move to cyclins and cyclin dependent kinases and the mechanism they follow.
This journey in regulation of cell cycle will take a halt after a general discussion of positive and negative cell cycle regulators.
Thankyou.
Molecular event during Cell cycle By KK Sahu SirKAUSHAL SAHU
WHAT IS CELL?
WHAT IS CELL DIVISION OR CELL CYCLE?
WHY DO CELL DIVIDE?
HISTORY
CELL CYCLE
INTERPHASE
M-PHASE
MOLECULAR EVENT DURING CELL CYCLE AND CELL REGULATION
TYPES OF CELL DIVISION
IMPORTANCE OF CELL DIVISION
ABNORMALTIES OF CELL CYCLE
REFRENCES
The cell cycle, or cell-division cycle, is the series of events that take place in a cell leading to duplication of its DNA (DNA replication) and division of cytoplasm and organelles to produce two daughter cells.
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
Ethnobotany and Ethnopharmacology:
Ethnobotany in herbal drug evaluation,
Impact of Ethnobotany in traditional medicine,
New development in herbals,
Bio-prospecting tools for drug discovery,
Role of Ethnopharmacology in drug evaluation,
Reverse Pharmacology.
Model Attribute Check Company Auto PropertyCeline George
In Odoo, the multi-company feature allows you to manage multiple companies within a single Odoo database instance. Each company can have its own configurations while still sharing common resources such as products, customers, and suppliers.
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!
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.
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.
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.
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.
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
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.
2. contents
Introduction
Cell cycle
The phases of mitotic cell cycle
Regulation of the cell cycle
Check points of the cell cycle
3. Introduction
• We have previously seen that prokaryotic replication can be
regulated by preventing initiation complex formation .
• Since eukaryotic replication is quite a bit similar to the
prokaryotic replication , it is expected that control of
initiation will play a role in the eukaryotes too.
• However , regulation here must be considerably more
complex not only because eukaryotic chromosomes have
several replicons, but also – and probably more importantly
so- because the cell cycle in eukaryotes in much much more
complex.
• As one considers the process of mitosis, keep in mind that
the structural and functional changes are regulated by the
cell cycle machinery.
4. Cell cycle
Defination :- when the cell has grown to its
maximum size it divides , and it take place a series
of changes in a newly formed cell which involve in
growth and division to form 2 daughter cells, it is
called cell cycle.
It consist of two stages,
1. A non dividing growing interphase
2. A short dividing mitotic / M phase
5. The phases of mitotic cell cycle
The period between 2 mitotic division is called Interphase.
It is further divisible into 3 stages:
1. G1 phase
2. S phase
3. G2 phase
G1 phase:- It is post mitotic phase and takes place at the
end of cell division the newly formed cells accumulate the
energy and prepares themselves for the synthesis of DNA.
During this, active synthesis of RNA and protein takes place.
6.
7. S phase :- It is the synthesis phase during this phase
duplication of DNA and centriol takes places.
The duplication of DNA results in the duplication of
chromosomes.
G2 phase:- It is the pre-mitotic gap phase (invisible
phase) the synthesis of RNA and protein continues in
this phase.
The formation of macro molecules for spindle
formation takes place and the cell prepare itself to go
into the mitotic phase.
8. Mitotic phase
• M phase follows the interphase. This last for a short
period compare to interphase.
• During this phase 2 important processes occur
simultaneously they are,
Karyokinesis (division of nucleus): It results in the
separation of chromosomes into 2 equal groups.
Cytokinesis (division of cytoplasm):- It results in
division of cytoplasmic components into
approximately 2 halves.
• After M phase a cell may either enter interphase to
repeat the cell cycle or G0 phase to arrest the cell
cycle.
• The cells in G0 phase may grow in size and get
differentiated.
9. Regulation of the cell cycle &
checkpoints
• Mitotic chromosome cycle is found to be regulated
by the following 3 control factors :
1. The S –phase activator that normally appears in
the cytoplasm only during S –phase and ‘switches
on ‘ DNA synthesis (Rao and Johanson ,1970).
2. The M-phase promoting factor (MPF) that is
present only in M-phase cytoplasm and causes
chromosomes condensation .
3. The DNA- dependent M-phase delaying factor
that is present in S-phase cytoplasm and inhibits
the process leading to onset of MPF production.
10. • Each successive step depends on a preceding one (all
processes of chromosomes cycle are linked together as
dependent sequence).Thus,
1. The cell can not pass through mitosis until MPF has been
produced
2. MPF cannot be produced until M-phase –delaying factor
has disappeared
3. The M-phase delaying factor and S –phase activator cannot
disappear until DNA – synthesis has ended
4. DNA synthesis cannot end until all of the DNA has
replicated
5. The DNA cannot begin to replicate until DNA re-replication
block has been removed by passage through mitosis into
G1 and lastly
6. A cell cannot progress from mitosis into G1 , until the
chromosomes have separated on the mitotic spindle.
11.
12. A check point in the cell cycle is a critical control point
where stop and go signals regulate the cycle.
3 major checkpoints are found in the G1, G2, and M
phases.
G2 checkpoint control by MPF
Active MPF(Maturation promoting factor) = mitotic
Cdk + mitotic cyclin
Cdk is cyclin –dependant kinase
MPF controls G2 → phosphorylating and activating
proteins involving in :-
• chromosome condensation
• Nuclear envelope breakdown
• Spindle assembly
13.
14. • The cell cycle is regulated by protein kinases.
• The mechanism regulating the progression of cells
through their division cycle is highly conserved in
evolution, and plants have retained the basic
components of this mechanism.
• The key enzymes that control the transitions
between the different states of the cell cycle, and
the entry of nondividing cells into the cell cycle,
are the cyclin-dependant protein kinases,or CDKs.
• Endogenous hormones such as auxin, cytokinins,
abscisic acid, gibberellins and brassinosteroids as
well as enviornmental factors all regulate
progression through the cell cycle.
15. • Protein kinases are enzymes that phosphorylate
proteins using ATP.
• The regulated activity of CDKs is essential for the
transitions from G1 to S and from G2 to M, and for
the entry of nondividing cells into the cell cycle.
• The transition from G1 to S requires a set of cyclins
(G1 cyclins ) different from those required in the
transition from G2 to mitosis, where mitotic cyclins
activate the CDKs.
16. • Similarly, protein phosphatases can remove
phosphate from CDKs, either stimulating or
inhibiting their activity, depending on the position
of the phosphate.
• CDK activity can be regulated in various ways, but
2 of the most important mechanisms are
1. Cyclins synthesis and destruction and
2. The phosphorylation and dephosphorylation of
key amino acid residues within the CDK protein.
17. Summary : - Cell cycle control
A “clock” is running within the cell – of synthesis
and degradation of cyclins- which activate cyclin-
dependate kinases (Cdk’s ) which activate other
proteins to causes checkpoints transitions.
The “clock” is adjusted (cyclins and Cdk’s are
regulated ) by other proteins, based on :
External signals (growth factors )
Internal signals (correct completion of previous
step )