Microscopes allow scientists to see objects that are too small for the naked eye by using lenses that magnify images of specimens up to hundreds of thousands of times their actual size. There are two main types of microscopes - light microscopes, which are inexpensive and easy to use, and electron microscopes, which have much higher magnifying powers and resolving abilities but require more complex equipment. Different microscopes reveal different structural details of cells and organisms depending on their magnification power and resolving abilities.
A CAPE Biology PPT on Cells Structure and Functions. A long with explanations on the various cells. It gives you information on the plant and animal cells and how the organisms within both cells function.
A CAPE Biology PPT on Cells Structure and Functions. A long with explanations on the various cells. It gives you information on the plant and animal cells and how the organisms within both cells function.
A level Biology - Cells, Viruses and Reproduction of Living Thingsmrexham
This is a PowerPoint presentation for Topic 2 in the Edexcel Biology B A Level course that starts in 2015.
This is a free sample, the full PowerPoint presentation is available to purchase here: https://sellfy.com/MrExham
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.Sérgio Sacani
The return of a sample of near-surface atmosphere from Mars would facilitate answers to several first-order science questions surrounding the formation and evolution of the planet. One of the important aspects of terrestrial planet formation in general is the role that primary atmospheres played in influencing the chemistry and structure of the planets and their antecedents. Studies of the martian atmosphere can be used to investigate the role of a primary atmosphere in its history. Atmosphere samples would also inform our understanding of the near-surface chemistry of the planet, and ultimately the prospects for life. High-precision isotopic analyses of constituent gases are needed to address these questions, requiring that the analyses are made on returned samples rather than in situ.
A level Biology - Cells, Viruses and Reproduction of Living Thingsmrexham
This is a PowerPoint presentation for Topic 2 in the Edexcel Biology B A Level course that starts in 2015.
This is a free sample, the full PowerPoint presentation is available to purchase here: https://sellfy.com/MrExham
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.Sérgio Sacani
The return of a sample of near-surface atmosphere from Mars would facilitate answers to several first-order science questions surrounding the formation and evolution of the planet. One of the important aspects of terrestrial planet formation in general is the role that primary atmospheres played in influencing the chemistry and structure of the planets and their antecedents. Studies of the martian atmosphere can be used to investigate the role of a primary atmosphere in its history. Atmosphere samples would also inform our understanding of the near-surface chemistry of the planet, and ultimately the prospects for life. High-precision isotopic analyses of constituent gases are needed to address these questions, requiring that the analyses are made on returned samples rather than in situ.
Multi-source connectivity as the driver of solar wind variability in the heli...Sérgio Sacani
The ambient solar wind that flls the heliosphere originates from multiple
sources in the solar corona and is highly structured. It is often described
as high-speed, relatively homogeneous, plasma streams from coronal
holes and slow-speed, highly variable, streams whose source regions are
under debate. A key goal of ESA/NASA’s Solar Orbiter mission is to identify
solar wind sources and understand what drives the complexity seen in the
heliosphere. By combining magnetic feld modelling and spectroscopic
techniques with high-resolution observations and measurements, we show
that the solar wind variability detected in situ by Solar Orbiter in March
2022 is driven by spatio-temporal changes in the magnetic connectivity to
multiple sources in the solar atmosphere. The magnetic feld footpoints
connected to the spacecraft moved from the boundaries of a coronal hole
to one active region (12961) and then across to another region (12957). This
is refected in the in situ measurements, which show the transition from fast
to highly Alfvénic then to slow solar wind that is disrupted by the arrival of
a coronal mass ejection. Our results describe solar wind variability at 0.5 au
but are applicable to near-Earth observatories.
This pdf is about the Schizophrenia.
For more details visit on YouTube; @SELF-EXPLANATORY;
https://www.youtube.com/channel/UCAiarMZDNhe1A3Rnpr_WkzA/videos
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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.
(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.
Introduction:
RNA interference (RNAi) or Post-Transcriptional Gene Silencing (PTGS) is an important biological process for modulating eukaryotic gene expression.
It is highly conserved process of posttranscriptional gene silencing by which double stranded RNA (dsRNA) causes sequence-specific degradation of mRNA sequences.
dsRNA-induced gene silencing (RNAi) is reported in a wide range of eukaryotes ranging from worms, insects, mammals and plants.
This process mediates resistance to both endogenous parasitic and exogenous pathogenic nucleic acids, and regulates the expression of protein-coding genes.
What are small ncRNAs?
micro RNA (miRNA)
short interfering RNA (siRNA)
Properties of small non-coding RNA:
Involved in silencing mRNA transcripts.
Called “small” because they are usually only about 21-24 nucleotides long.
Synthesized by first cutting up longer precursor sequences (like the 61nt one that Lee discovered).
Silence an mRNA by base pairing with some sequence on the mRNA.
Discovery of siRNA?
The first small RNA:
In 1993 Rosalind Lee (Victor Ambros lab) was studying a non- coding gene in C. elegans, lin-4, that was involved in silencing of another gene, lin-14, at the appropriate time in the
development of the worm C. elegans.
Two small transcripts of lin-4 (22nt and 61nt) were found to be complementary to a sequence in the 3' UTR of lin-14.
Because lin-4 encoded no protein, she deduced that it must be these transcripts that are causing the silencing by RNA-RNA interactions.
Types of RNAi ( non coding RNA)
MiRNA
Length (23-25 nt)
Trans acting
Binds with target MRNA in mismatch
Translation inhibition
Si RNA
Length 21 nt.
Cis acting
Bind with target Mrna in perfect complementary sequence
Piwi-RNA
Length ; 25 to 36 nt.
Expressed in Germ Cells
Regulates trnasposomes activity
MECHANISM OF RNAI:
First the double-stranded RNA teams up with a protein complex named Dicer, which cuts the long RNA into short pieces.
Then another protein complex called RISC (RNA-induced silencing complex) discards one of the two RNA strands.
The RISC-docked, single-stranded RNA then pairs with the homologous mRNA and destroys it.
THE RISC COMPLEX:
RISC is large(>500kD) RNA multi- protein Binding complex which triggers MRNA degradation in response to MRNA
Unwinding of double stranded Si RNA by ATP independent Helicase
Active component of RISC is Ago proteins( ENDONUCLEASE) which cleave target MRNA.
DICER: endonuclease (RNase Family III)
Argonaute: Central Component of the RNA-Induced Silencing Complex (RISC)
One strand of the dsRNA produced by Dicer is retained in the RISC complex in association with Argonaute
ARGONAUTE PROTEIN :
1.PAZ(PIWI/Argonaute/ Zwille)- Recognition of target MRNA
2.PIWI (p-element induced wimpy Testis)- breaks Phosphodiester bond of mRNA.)RNAse H activity.
MiRNA:
The Double-stranded RNAs are naturally produced in eukaryotic cells during development, and they have a key role in regulating gene expression .
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.
7. In order to measure objects in the microscopic world,
we need to use very small units of measurement
The smallest structure visible with the human eye is about 50–100 μm in diameter
(roughly the diameter of the sharp end of a pin). The cells in your body vary in size from
about 5 μm to 40 μm
8. There are two fundamentally different types of
microscope:
Light
Microscope
Electron
Microscope
9.
10. 3 MAIN PARTS:
Head: The upper part of the
microscope that houses the optical
elements of the unit.
Base: The bottom of the
microscope—what the microscope
stands on.
Arm: Structural element that
connects the head of the
microscope to the base.
11. Eyepiece: The lens the viewer looks
through to see the specimen. The eyepiece
usually contains a 10X or 15X power lens.
Body tube (Head): The body tube
connects the eyepiece to the objective
lenses.
Nosepiece/Revolver: A rotating turret
that houses the objective lenses. The
viewer spins the nosepiece to select
different objective lenses.
Coarse adjustment: Brings the specimen
into general focus.
Fine adjustment: Fine tunes the focus
and increases the detail of the specimen.
Objective lenses: One of the most
important parts of a compound
microscope, as they are the lenses closest
to the specimen. A standard microscope
has three, four, or five objective lenses
that range in power from 4X to 100X.
12. Specimen or slide: The specimen is the
object being examined. Most specimens
are mounted on slides, flat rectangles of
thin glass.
Stage: The flat platform where the slide is
placed.
Stage clips: Metal clips that hold the slide
in place.
Stage height adjustment (Stage
Control): These knobs move the stage left
and right or up and down.
Aperture: The hole in the middle of the
stage that allows light from the illuminator
to reach the specimen.
On/off switch: This switch on the base of
the microscope turns the illuminator off
and on.
Illumination: The light source for a
microscope.
Iris diaphragm: Adjusts the amount of
light that reaches the specimen.
Condenser: Gathers and focuses light
from the illuminator onto the specimen
being viewed.
23. Electron microscopes
There are two main types of electron microscope:
⚪ The transmission electron microscope [TEM].
● A beam of electrons passes through the specimen and is dispersed by the
structures there. The scattered electrons are then captured on a photographic
plate.
⚪ The scanning electron microscope [SEM].
● The specimen is coated in a very thin layer of metal and a beam of electrons is
bounced off the surface onto a photographic plate. This allows 3-D images to
be formed.
24. Advantages/Disadvantages of EM
Advantages of EM Disadvantages of EM
Resolution is x2000 more than
LM
Samples have to be placed in a
vacuum
Produces detailed images Very expensive
SEM produces 3D images Need to be highly skilled to
create samples
30. LIMITATIONS
⚪ BOTH:
⚪ MUST BE IN A VACUUM – SO
⚪ LIVING SPECIMENS CAN’T BE OBSERVED
⚪ COMPLEX STAINING PROCESS REQUIRED BUT
⚪ IMAGE STILL BLACK AND WHITE
⚪ IMAGE MAY CONTAIN ARTEFACTS
⚪ TEM
⚪ SPECIMEN MUST BE V. THIN
⚪ TO ALLOW THE ELECTRONS TO PENETRATE
⚪ THEREFORE – FLAT 2D IMAGE
⚪ CAN OVEROME BY TAKING SERIES OFSECTIONS
⚪ SEM
⚪ LOWER RESOLVING POWER THAN TEM BUT STILL TEN TIMES
BETTER THAN LIGHT MICROSCOPE
34. The basic unit of all living organisms; it is surrounded
by a cell surface membrane and contains genetic
material (DNA) and cytoplasm containing organelles
What is cell?
37. Why should we learn about cells?
After all, our bodies are made up of trillions of cells. By
learning about cells, we come to understand how we can:
• protect cells to prevent infection and other harmful effects
• observe cells to diagnose disease
• treat cells to heal illnesses
• stop harming cells through our choices and actions
38.
39. All cells have an internal structure known as
the ultra structure.
2 types of cell
Eukaryotic - Organisms made of cells with
membrane-bound nuclei
Prokaryotic - The simpler cells lacking
membrane-bound nuclei
Eukaryotic cells have a distinct nucleus and
possess membrane bound organelles, and
epithelial cells are concerned with absorption
and secretion.
43. Prokaryotes
● Simple cells with few organelles (structures) inside them
● Bacteria such as cholera are prokaryotic
● Made up of:
❏ Plasmids – small circular DNA strands
❏ Genetic material – DNA
❏ Cell surface membrane
❏ Cell wall
❏ Capsule – protective
❏ Flagellum – to move
❏ Mesosome – site of respiration
All prokaryotic organisms are unicellular
44. No nucleus yet
No nuclear membrane
Diameter of 0.1 - 1 µm
Smaller than Eukaryotes
49. Eukaryotes
➢ Nucleus
➢ Nuclear membrane that
surrounds the nucleus, in
which the well-defined
chromosomes (bodies
containing the hereditary
material) are located.
➢ Organelles
➢ Diameter of 10 - 100 µm
➢ Eukaryotic organisms unlike
prokaryotic can be unicellular or
multicellular.
50. Nucleus
● ›Contains genetic material and controls
cell activity. Made up of:
● ›The nuclear envelope – double membrane that
controls material entry and exit
● ›Nuclear pores – allows large molecules like mRNA
out of the nucleus
● ›Chromatin – made of proteins and DNA. Controls
the cell activity
● ›Nucleolus – makes ribosomes
55. Eukaryotic cells can be multicellular
• The whole cell can be specialized for one job
• cells can work together as tissues
• Tissues can work together as organs
57. Organelle
An organelle is a structure within a cell. Organelles work
together to carry out specific functions that support the
life of the cell. These functions include :
• bringing in nutrients
• removing wastes
• generating and releasing energy for the cell to use
• making substances that the cell needs
• reproducing
58. How do these cells reproduce?
Eukaryote
Prokaryote
Meiosis
Mitosis
Cell division creating 2
identical cells
Binary Fission
Division of cells into
smaller parts than
regeneration
Sexual Reproduction
Asexual Reproduction
59. Similarities
• Both types of cells have cell
membranes (outer covering of
the cell)
• Both types of cells have
ribosomes
• Both types of cells have DNA
• Both types of cells have a liquid
environment known as the
cytoplasm
60. The Difference
Name Characteristics Eukaryotic Cells Prokaryotic Cells
Nadya Organelles Has a complex
organelles (nucleus)
to support the life of
the cells
Have a few
organelles
Levia cytoplasm Has a Cellular
organelle
Cytoplasm doesn’t
have organelles
Rio Cell membrane0 Has cell membrane
bound
Has no cell
membrane bound
Daanisy Cellular activities Unicellular &
Multicellular
Unicellular
