This document discusses DNA replication. It begins by defining DNA replication as the process of producing two identical copies of DNA from one original DNA molecule. It then describes some of the key biological significance of DNA replication, such as maintaining genomic integrity between generations. The document goes on to explain the basic rules and mechanisms of DNA replication, including semi-conservative replication, replication forks, and the roles of various replication proteins like DNA polymerase, helicase, and ligase. It also discusses the initiation, elongation, and termination stages of replication.
DNA replication is the process by which DNA makes a copy of itself during cell division.The separation of the two single strands of DNA creates a 'Y' shape called a replication 'fork'. The two separated strands will act as templates for making the new strands of DNA.
DNA replication is the process by which DNA makes a copy of itself during cell division.The separation of the two single strands of DNA creates a 'Y' shape called a replication 'fork'. The two separated strands will act as templates for making the new strands of DNA.
replication of DNA to form two daughter DNA molecules, basis of cell division and transfer of genetic information from one generation to other generation
DNA replication, repair and recombination NotesYi Fan Chen
DNA, replication, repair and recombination Notes based on Molecular biology of the cell. Biology Elite: biologyelite.weebly.com, please use together with the presentation
In molecular biology, DNA replication is the biological process of producing two identical replicas of DNA from one original DNA molecule. DNA replication occurs in all living organisms acting as the basis for biological inheritance. The cell possesses the distinctive property of division, which makes replication of DNA essential.
Autoimmune disease HEMOLYTIC ANEMIA AND DIABETESArchanaSoni3
An autoimmune disease is a condition in which your immune system mistakenly attacks your body.
The immune system normally guards against germs like bacteria and viruses. When it senses these foreign invaders, it sends out an army of fighter cells to attack them.
Normally, the immune system can tell the difference between foreign cells and your own cells.
In an autoimmune disease, the immune system mistakes part of your body — like your joints or skin — as foreign. It releases proteins called autoantibodies that attack healthy cells.
Some autoimmune diseases target only one organ. Type 1 diabetes damages the pancreas. Other diseases, like lupus, affect the whole body.
endocytosis and exocytosis is a procss of cell eating and drinnking. it is a mazor tool for self defence to an individual cell. there are some molecular mechanism for this process described in given notes.
(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...Scintica Instrumentation
Intravital microscopy (IVM) is a powerful tool utilized to study cellular behavior over time and space in vivo. Much of our understanding of cell biology has been accomplished using various in vitro and ex vivo methods; however, these studies do not necessarily reflect the natural dynamics of biological processes. Unlike traditional cell culture or fixed tissue imaging, IVM allows for the ultra-fast high-resolution imaging of cellular processes over time and space and were studied in its natural environment. Real-time visualization of biological processes in the context of an intact organism helps maintain physiological relevance and provide insights into the progression of disease, response to treatments or developmental processes.
In this webinar we give an overview of advanced applications of the IVM system in preclinical research. IVIM technology is a provider of all-in-one intravital microscopy systems and solutions optimized for in vivo imaging of live animal models at sub-micron resolution. The system’s unique features and user-friendly software enables researchers to probe fast dynamic biological processes such as immune cell tracking, cell-cell interaction as well as vascularization and tumor metastasis with exceptional detail. This webinar will also give an overview of IVM being utilized in drug development, offering a view into the intricate interaction between drugs/nanoparticles and tissues in vivo and allows for the evaluation of therapeutic intervention in a variety of tissues and organs. This interdisciplinary collaboration continues to drive the advancements of novel therapeutic strategies.
Nutraceutical market, scope and growth: Herbal drug technologyLokesh Patil
As consumer awareness of health and wellness rises, the nutraceutical market—which includes goods like functional meals, drinks, and dietary supplements that provide health advantages beyond basic nutrition—is growing significantly. As healthcare expenses rise, the population ages, and people want natural and preventative health solutions more and more, this industry is increasing quickly. Further driving market expansion are product formulation innovations and the use of cutting-edge technology for customized nutrition. With its worldwide reach, the nutraceutical industry is expected to keep growing and provide significant chances for research and investment in a number of categories, including vitamins, minerals, probiotics, and herbal supplements.
This pdf is about the Schizophrenia.
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Richard's entangled aventures in wonderlandRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
Seminar of U.V. Spectroscopy by SAMIR PANDASAMIR PANDA
Spectroscopy is a branch of science dealing the study of interaction of electromagnetic radiation with matter.
Ultraviolet-visible spectroscopy refers to absorption spectroscopy or reflect spectroscopy in the UV-VIS spectral region.
Ultraviolet-visible spectroscopy is an analytical method that can measure the amount of light received by the analyte.
2. DNA REPLICATION
DNA REPLICATION IS THE BIOLOGICAL PROCESS OF
PRODUCING TWO IDENTICAL REPLICAS OF DNA FROM
ONE ORIGINAL DNA MOLECULE.
BIOLOGICAL SIGNIFICANCE
• EXTREME ACCURACY OF DNA REPLICATION IS
NECESSARY IN ORDER TO PRESERVE THE INTEGRITY
OF THE GENOME IN SUCCESSIVE GENERATIONS
• IN EUKARYOTES , REPLICATION ONLY OCCURS DURING
THE S PHASE OF THE CELL CYCLE.
• REPLICATION RATE IN EUKARYOTES IS SLOWER
RESULTING IN A HIGHER FIDELITY/ACCURACY OF
REPLICATION IN EUKARYOTES
4. BASIC RULES OF REPLICATION
a. SEMI-
CONSERVATIVE
b. STARTS AT THE
‘ORIGIN’
c. SYNTHESIS
ALWAYS IN THE 5-3’
DIRECTION
d. CAN BE UNI OR
BIDIRECTIONAL
e. SEMI-
DISCONTINUOUS
f. RNA PRIMERS
REQUIRED
5. THE MECHANISM OF DNA
REPLICATION
ARTHUR KORNBERG, A NOBEL PRIZE WINNER AND OTHER
BIOCHEMISTS DEDUCED STEPS OF REPLICATION
• INITIATION
• PROTEINS BIND TO DNA AND OPEN UP DOUBLE HELIX
• PREPARE DNA FOR COMPLEMENTARY BASE PAIRING
• ELONGATION
• PROTEINS CONNECT THE CORRECT SEQUENCES OF NUCLEOTIDES
INTO A CONTINUOUS NEW STRAND OF DNA
• TERMINATION
• PROTEINS RELEASE THE REPLICATION COMPLEX
6. INITIATION
• THIS PROCESS IS
INITIATED AT PARTICULAR
POINTS IN THE DNA,
KNOWN AS "ORIGINS",
WHICH ARE TARGETED
BY INITIATOR PROTEINS.
EX: DNAA IN E.
COLI; ORIGIN
RECOGNITION COMPLEX IN
YEAST
• SEQUENCES USED BY
INITIATOR PROTEINS TEND
TO BE "AT-RICH“
7. ELONGATION
• IN THIS MECHANISM, ONCE THE TWO STRANDS ARE
SEPARATED, PRIMASE ADDS RNA PRIMERS TO THE
TEMPLATE STRANDS.
• THE LEADING STRAND RECEIVES ONE RNA PRIMER WHILE
THE LAGGING STRAND RECEIVES SEVERAL.
• THE LEADING STRAND IS CONTINUOUSLY EXTENDED
FROM THE PRIMER BY A DNA POLYMERASE WITH
HIGH PROCESSIVITY, WHILE THE LAGGING STRAND IS
EXTENDED DISCONTINUOUSLY FROM EACH PRIMER
FORMING OKAZAKI FRAGMENTS.
• RNASE REMOVES THE PRIMER RNA FRAGMENTS, AND A
LOW PROCESSIVITY DNA POLYMERASE DISTINCT FROM
THE REPLICATIVE POLYMERASE ENTERS TO FILL THE
GAPS.
8.
9. ELONGATION
• WHEN THIS IS COMPLETE, A SINGLE NICK ON THE
LEADING STRAND AND SEVERAL NICKS ON THE
LAGGING STRAND CAN BE FOUND.
• LIGASE WORKS TO FILL THESE NICKS IN, THUS
COMPLETING THE NEWLY REPLICATED DNA
MOLECULE.
• AS DNA SYNTHESIS CONTINUES, THE ORIGINAL
DNA STRANDS CONTINUE TO UNWIND ON EACH
SIDE OF THE BUBBLE, FORMING A REPLICATION
FORK WITH TWO PRONGS.
• IN BACTERIA, WHICH HAVE A SINGLE ORIGIN OF
10. REPLICATION FORK
• IT IS CREATED BY HELICASES. THE RESULTING
STRUCTURE HAS TWO BRANCHING "PRONGS", EACH
ONE MADE UP OF A SINGLE STRAND OF DNA. THESE
TWO STRANDS SERVE AS THE TEMPLATE FOR THE
LEADING AND LAGGING STRANDS, WHICH WILL BE
CREATED AS DNA POLYMERASE MATCHES
COMPLEMENTARY NUCLEOTIDES TO THE
TEMPLATES.
a: template, b: leading strand, c: lagging strand, d: replication fork, e: primer, f:Okazaki fragments
11. DNA REPLICATION PROTEINS
Enzyme Function in DNA replication
DNA Helicase
Also known as helix destabilizing enzyme. Unwinds the DNA double
helix at the Replication Fork.
DNA Polymerase
Builds a new duplex DNA strand by adding nucleotides in the 5' to 3'
direction. Also performs proof-reading and error correction.
DNA clamp
A protein which prevents elongating DNA polymerases from dissociating
from the DNA parent strand.
Single-Strand
Binding (SSB)
Proteins
Bind to ssDNA and prevent the DNA double helix from re-annealing
after DNA helicase unwinds it, thus maintaining the strand separation,
and facilitating the synthesis of the nascent strand.
Topoisomerase Relaxes the DNA from its super-coiled nature.
DNA Gyrase
Relieves strain of unwinding by DNA helicase; this is a specific type of
topoisomerase
DNA Ligase
Re-anneals the semi-conservative strands and joins Okazaki
Fragments of the lagging strand.
Primase
Provides a starting point of RNA (or DNA) for DNA polymerase to begin
synthesis of the new DNA strand.
Telomerase
Lengthens telomeric DNA by adding repetitive nucleotide sequences to
the ends of eukaryotic chromosomes. This allows germ cells and stem
cells to avoid the Hayflick limit on cell division.
13. TERMINATION
• TERMINATION REQUIRES THAT THE PROGRESS OF
THE DNA REPLICATION FORK MUST STOP OR BE
BLOCKED.
• TERMINATION AT A SPECIFIC LOCUS INVOLVES THE
INTERACTION BETWEEN TWO COMPONENTS:
(1) A TERMINATION SITE SEQUENCE IN THE
DNA
(2) A PROTEIN WHICH BINDS TO THIS
SEQUENCE TO PHYSICALLY STOP DNA REPLICATION.
• IN VARIOUS BACTERIAL SPECIES, THIS IS NAMED THE
DNA REPLICATION TERMINUS SITE-BINDING