This slideshow contains various stages of cell cycle regulation, cell cycle checkpoints and their proteins involved in regulation. Cell cycle checkpoints transition phases.
This slideshow contains various stages of cell cycle regulation, cell cycle checkpoints and their proteins involved in regulation. Cell cycle checkpoints transition phases.
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.
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.
Cyclin-dependent kinases (CDKs) belong to a protein serine/threonine kinases whose activity depends on association with a noncatalytic regulatory subunit called a cyclin. Cyclin-dependent kinases inhibitors are vital for progression through the cell cycle and proliferation.
This is a short presentation which helps to understand Cell cycle and Regulation. But it is recommended to read Lodish as reference material to understand this.
cellcycle,cell cycle regulation,phases of cell cycle,cell injury,etiology of cell injury,mechanism of cell injury,apoptosisand necrosis,autophagy,cell death
By using flow cytometry, staining dyes are needed. Creative Bioarray can choose different dyes to perform the assays, including propidium iodide (PI), BrdU, 7-amino actinomycin-D (7-AAD), Hoechst 33342 and 33258, and 4’6’-diamidino-2-phenylindole (DAPI), based on the customer’s applications or requirements.
https://www.creative-bioarray.com/cell-cycle-assays.htm
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.
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.
Cyclin-dependent kinases (CDKs) belong to a protein serine/threonine kinases whose activity depends on association with a noncatalytic regulatory subunit called a cyclin. Cyclin-dependent kinases inhibitors are vital for progression through the cell cycle and proliferation.
This is a short presentation which helps to understand Cell cycle and Regulation. But it is recommended to read Lodish as reference material to understand this.
cellcycle,cell cycle regulation,phases of cell cycle,cell injury,etiology of cell injury,mechanism of cell injury,apoptosisand necrosis,autophagy,cell death
By using flow cytometry, staining dyes are needed. Creative Bioarray can choose different dyes to perform the assays, including propidium iodide (PI), BrdU, 7-amino actinomycin-D (7-AAD), Hoechst 33342 and 33258, and 4’6’-diamidino-2-phenylindole (DAPI), based on the customer’s applications or requirements.
https://www.creative-bioarray.com/cell-cycle-assays.htm
The study of the cell cycle focuses on mechanisms that regulate the timing and frequency of DNA duplication and cell division. As a biological concept, the cell cycle is defined as the period between successive divisions of a cell. During this period, the contents of the cell must be accurately replicated.
The cell cycle is regulated by cyclins and cyclin-dependent kinases.
How long is one cell cycle?
Depends. Eg. Skin cells every 24 hours. Some bacteria every 2 hours. Some cells every 3 months. Cancer cells very short. Nerve cells never.
Programmed cell death:
Each cell type will only do so many cell cycles then die. (Apoptosis)
OVERVIEW OF CELL CYCLE
Explained in brief phases of cell cycle . Given a explanation of each phase in detail, also explained the significance of meiosis in brief.
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.
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.
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
A brief information about the SCOP protein database used in bioinformatics.
The Structural Classification of Proteins (SCOP) database is a comprehensive and authoritative resource for the structural and evolutionary relationships of proteins. It provides a detailed and curated classification of protein structures, grouping them into families, superfamilies, and folds based on their structural and sequence similarities.
Cancer cell metabolism: special Reference to Lactate PathwayAADYARAJPANDEY1
Normal Cell Metabolism:
Cellular respiration describes the series of steps that cells use to break down sugar and other chemicals to get the energy we need to function.
Energy is stored in the bonds of glucose and when glucose is broken down, much of that energy is released.
Cell utilize energy in the form of ATP.
The first step of respiration is called glycolysis. In a series of steps, glycolysis breaks glucose into two smaller molecules - a chemical called pyruvate. A small amount of ATP is formed during this process.
Most healthy cells continue the breakdown in a second process, called the Kreb's cycle. The Kreb's cycle allows cells to “burn” the pyruvates made in glycolysis to get more ATP.
The last step in the breakdown of glucose is called oxidative phosphorylation (Ox-Phos).
It takes place in specialized cell structures called mitochondria. This process produces a large amount of ATP. Importantly, cells need oxygen to complete oxidative phosphorylation.
If a cell completes only glycolysis, only 2 molecules of ATP are made per glucose. However, if the cell completes the entire respiration process (glycolysis - Kreb's - oxidative phosphorylation), about 36 molecules of ATP are created, giving it much more energy to use.
IN CANCER CELL:
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
introduction to WARBERG PHENOMENA:
WARBURG EFFECT Usually, cancer cells are highly glycolytic (glucose addiction) and take up more glucose than do normal cells from outside.
Otto Heinrich Warburg (; 8 October 1883 – 1 August 1970) In 1931 was awarded the Nobel Prize in Physiology for his "discovery of the nature and mode of action of the respiratory enzyme.
WARNBURG EFFECT : cancer cells under aerobic (well-oxygenated) conditions to metabolize glucose to lactate (aerobic glycolysis) is known as the Warburg effect. Warburg made the observation that tumor slices consume glucose and secrete lactate at a higher rate than normal tissues.
2. INTRODUCTION
The process of cell reproduction replaces dead cells with new ones; repairs
damaged tissues and allow living organisms to grow. One of the first
processes in the human body is cell division. During cell division, two
events occur. The replicated genetic material is equally distributed to two
daughter nuclei in a process called Mitosis, following which the cell gets
separated into two in a process called Cytokinesis.
Meiosis is a specialized type of cell division that reduces the chromosome
number by half, creating four haploid cells, each genetically distinct from
the parent cell that gave rise to them. This process occurs in all sexually
reproducing single-celled and multicellular eukaryotes, including animals,
plants, and fungi.
3. THE CELL CYCLE
All cells go through the same basic cycle,
but they vary in the amount of time they
spend in each stage. Once begun, a cell
division is a continuous process without a
beginning or an end. It is a cycle which
helps the cell to grow and divide.
4. PHASES IN CELL CYCLE
• G0 phase: During the G0 phase, cells are not considered to be in the
cycle of division but become specialized or differentiated in their
function. It is at this time they mature to play the role specified by the
genes.
• G1 phase: The cell grows in volume as it produces tRNA, mRNA,
ribosomes, enzymes and other cell components.
• S phase: DNA Replication occurs in preparation for the distribution of
genes to daughter cells
• G2 phase: The final preparations are made for mitosis with the synthesis
of spindle-fibers proteins.
6. PROPHASE
Prophase is generally termed as the first phase of
mitosis and is when one of the most noticeable
changes occurs. As prophase proceeds, and as the
chromosomes become more visible, we recognize
that each chromosome is made up of two parallel
threadlike parts lying side by side. Each parallel
thread is termed as the chromatid. These
Chromatids are formed during the S phase. The
two chromatids are attached at a genetic region
called the Centromere
Several other changes occur as the cell proceeds
further into prophase. One of them is the
replication of centrioles. As the centrioles replicate,
they move into the spindle. The spindle is an array
of microtubules extending from pole to pole and is
used in the movement of chromosomes.
7. METAPHASE
During metaphase, the second stage in mitosis, the
chromosomes align at the equatorial plane. There
is no nucleus present during metaphase, and the
spindle, which started to form during the
prophase, is completed. The centrioles are at the
poles and the microtubules extend between them
to form the spindle. Then the move until they align
themselves along the equatorial planes at the
equator.
Even at this stage of mitosis each chromosomes
consists of two chromatids attached at a
centromere.
8. ANAPHASE
Anaphase is the third stage of mitosis. The nuclear
membrane is still absent and the chromosome
separate as the move along the spindle fibers
towards the opposite ends of the poles. As the
separation of chromatids occurs, the chromatids
are called daughter chromosomes and they
contain identical genetic information.
At the centromere is a protein structure called
kinetochore. This kinetochore has a protein called
kinesin or the motor protein which is responsible
for the movement of the chromatids
With the aid of ATP, the components of the
spindle protein are clipped of and are pulled
towards the pole.
9. TELOPHASE
Telophase is the last stage of mitosis.
Each set of chromosomes unwinds
and slowly a nuclear membrane starts
to form around them. The nucleoli
appear. Now the two cells have
identical daughter nuclei. In addition,
the microtubules disappear and so
does the spindle fibers. Cell furrow is
formed in animal cells and Cell Wall
gets divided in plant cells.
10. CYTOKINESIS
Cytokinesis is the breaking up of the
cytoplasm. In animal cells, the cell
furrow keeps on deepening and
finally the cell is divided into two
daughter cells. In plant cells the same
is achieved by the formation of the
cell wall. The cell is finally divided with
identical genetic material and the
organelles have also been replicated.
After this the cell starts to enter the
G1 stage. And get prepared for
another round of cell division
14. PROPHASE 1
Prophase I is typically the longest phase
of meiosis. During prophase I,
homologous chromosomes pair and
exchange DNA (homologous
recombination). This often results in
chromosomal crossover. This process is
critical for pairing between homologous
chromosomes and hence for accurate
segregation of the chromosomes at the
first meiosis division. The new
combinations of DNA created during
crossover are a significant source of
genetic variation, and result in new
combinations of alleles, which may be
beneficial.
15. METAPHASE 1
Homologous pairs move together along the
metaphase plate: As kinetochore
microtubules from both centrosomes attach
to their respective kinetochores, the paired
homologous chromosomes align along an
equatorial plane that bisects the spindle, due
to continuous counterbalancing forces
exerted on the bivalents by the microtubules
emanating from the two kinetochores of
homologous chromosomes. This attachment
is referred to as a bipolar attachment. The
physical basis of the independent assortment
of chromosomes is the random orientation
of each bivalent along the metaphase plate,
with respect to the orientation of the other
bivalents along the same equatorial line.
16. ANAPHASE 1
Kinetochore microtubules shorten,
pulling homologous chromosomes
(which consist of a pair of sister
chromatids) to opposite poles.
Nonkinetochore microtubules lengthen,
pushing the centrosomes farther apart.
The cell elongates in preparation for
division down the center.[14] Unlike in
mitosis, only the cohesin from the
chromosome arms is degraded while
the cohesin surrounding the centromere
remains protected. This allows the sister
chromatids to remain together while
homologs are segregated.
17. TELOPHASE 1
The first meiotic division effectively
ends when the chromosomes arrive at
the poles. Each daughter cell now has
half the number of chromosomes but
each chromosome consists of a pair of
chromatids. The microtubules that make
up the spindle network disappear, and a
new nuclear membrane surrounds each
haploid set. The chromosomes uncoil
back into chromatin. Cytokinesis, the
pinching of the cell membrane in animal
cells or the formation of the cell wall in
plant cells, occurs, completing the
creation of two daughter cells. Sister
chromatids remain attached during
telophase.
19. PROPHASE 11
In prophase II we see the
disappearance of the nucleoli and the
nuclear envelope again as well as the
shortening and thickening of the
chromatids. Centrosomes move to the
polar regions and arrange spindle
fibers for the second meiotic division.
20. METAPHASE 11
In metaphase II, the centromeres
contain two kinetochores that attach
to spindle fibers from the
centrosomes at opposite poles. The
new equatorial metaphase plate is
rotated by 90 degrees when
compared to meiosis I, perpendicular
to the previous plate
21. ANAPHASE 11
This is followed by anaphase II, in
which the remaining centromeric
cohesin is cleaved allowing the sister
chromatids to segregate. The sister
chromatids by convention are now
called sister chromosomes as they
move toward opposing poles
22. TELOPHASE 11
The process ends with telophase II,
which is similar to telophase I, and is
marked by decondensation and
lengthening of the chromosomes and
the disassembly of the spindle.
Nuclear envelopes reform and
cleavage or cell plate formation
eventually produces a total of four
daughter cells, each with a haploid set
of chromosomes.
Meiosis is now complete and ends up
with four new daughter cells
