Cell Communication, Cell Junction and Cell Signaling.pptxSheetal Patil
-Cellular Communication
-There are three stages of cell: communication
a.Reception
b.Transduction
c. Response
-Receptors And Ligands
There are two basic types of receptors:
a.Internal receptors
b.Cell surface receptors
-Internal receptors-often steroid hormones
-There are several different types of ligands
a.Hydrophobic ligands
b. Water soluble hydrophilic ligands
-Three stages of cell communication
-How insulin works
Cell Junction
-There are three types of cell junctions:
1.Adhesive (Anchoring) junctions
2.Tight Junctions
3.Gap Junactions
-The two main kinds of adhesive cell-cell junctions are:
a.Adherens junctions
b.Desmosomes
a. Adherens junctions:
Adherens junction is the cell to cell junction, which connects the actin filaments. In adherens junction, the membranes of the adjacent cells are held together by some transmembrane proteins called cadherins.
b. Desmosome
Desmosome is a cell to cell junction, where the intermediate filaments connect two adjacent cells. Desmosome is also called macula adherens. Desmosomes function like tight junctions. The trans-membrane proteins involved in desmosome are mainly cadherins.
2. Tight Junctions
The cell membranes are connected by strands of trans-membrane proteins such as claudins and occludins.
Tight junctions bind cells together, prevent molecules from passing in between the cells, and also help to maintain the polarity of cells.
-Functions of Tight Junctions:
Another function of tight junctions is simply to hold cells together.
3. Gap Junction
Gap junctions are a type of cell junction in which adjacent cells are connected through protein channels. Gap junctions are made up of connexin proteins. Groups of six connexins form a connexon, and two connexons are put together to form a channel that molecules can pass through. Other channels in gap junctions are made up of pannexin proteins.
-Functions of Gap Junction
The main function of gap junctions is to connect cells together so that molecules may pass from one cell to other.
This allows for cell-to-cell communication.
-Cell Signaling
Cell signaling is the process of cellular communication within the body. The binding of extracellular signaling molecules to their receptors
-Modes of cell-cell signaling
1.Direct cell-cell signaling
2. Signaling by secreted molecule
a.Endocrine signaling:
-E. g. hormones produced by endocrine glands including pituitary, pancreas, adrenal, parathyroid glands etc.
b.Paracrine signaling:
-E.g. action of neurotransmitters in carrying signals between nerve cells at a synapse.
c.Autocrine signaling:
-When interleukin-1 is produced in response to external stimuli, it can bind to cell-surface receptors on the same cell that produced it.
d.Synaptic signaling:
-Types of signaling molecules
a.Nitric oxide
b.Carbon monoxide
c.Neurotransmitter
d.Peptide hormone
-Intracellular signaling pathway activated by an extracellular signal molecule
power point presentation on the topic cellular level of organization from unit first of subject human anatomy and physiology I for first year B.PHARM it is useful for the student to study easily and find out the material easily for their study it is also useful for techers
Describe 3 functions of the cellular membrane and how are these func.pdffootworld1
Describe 3 functions of the cellular membrane and how are these functions accomplished by the
chemical make up of the membrane.
Solution
The main functions of the cell membrane are:to maintain the physical integrity of the cell,that is
to mechanically enclose the contents of the cell,also to control the movement of particles e.g.
ions or molecules,into and out of the cell.It also isolates the cytoplasm from the external
environment.
The hydrophilic head and hydrophobic tails of the phospholipid molecules that form the
phospholipid bilayer of the cell membrane forming its physical/mechanical structure.The ion
channels responsible for the selective permeability of the cell membrane.Membrane pumps that
enable active transport of specific molecules across the cell membrane.Carrier proteins and
receptor proteins that transport specific substance across the cell membrane and receive
(chemical) signals from outside the cell that tell the cell to take a specific
action,respectively.Cholesterol molecules and carbohydrate chains that support the structure of
the membrane and its attachment to other tissues,respectively.Surface protein markers that
identify the cell.Membrane proteins acts as a recptor to combine with specific substance such as
hormones while some form narrow passage ways or channels through which various molecules
and ions can cross the cell membrane.Enzymatic proteins carry out metabolic reactions..
Cell Communication, Cell Junction and Cell Signaling.pptxSheetal Patil
-Cellular Communication
-There are three stages of cell: communication
a.Reception
b.Transduction
c. Response
-Receptors And Ligands
There are two basic types of receptors:
a.Internal receptors
b.Cell surface receptors
-Internal receptors-often steroid hormones
-There are several different types of ligands
a.Hydrophobic ligands
b. Water soluble hydrophilic ligands
-Three stages of cell communication
-How insulin works
Cell Junction
-There are three types of cell junctions:
1.Adhesive (Anchoring) junctions
2.Tight Junctions
3.Gap Junactions
-The two main kinds of adhesive cell-cell junctions are:
a.Adherens junctions
b.Desmosomes
a. Adherens junctions:
Adherens junction is the cell to cell junction, which connects the actin filaments. In adherens junction, the membranes of the adjacent cells are held together by some transmembrane proteins called cadherins.
b. Desmosome
Desmosome is a cell to cell junction, where the intermediate filaments connect two adjacent cells. Desmosome is also called macula adherens. Desmosomes function like tight junctions. The trans-membrane proteins involved in desmosome are mainly cadherins.
2. Tight Junctions
The cell membranes are connected by strands of trans-membrane proteins such as claudins and occludins.
Tight junctions bind cells together, prevent molecules from passing in between the cells, and also help to maintain the polarity of cells.
-Functions of Tight Junctions:
Another function of tight junctions is simply to hold cells together.
3. Gap Junction
Gap junctions are a type of cell junction in which adjacent cells are connected through protein channels. Gap junctions are made up of connexin proteins. Groups of six connexins form a connexon, and two connexons are put together to form a channel that molecules can pass through. Other channels in gap junctions are made up of pannexin proteins.
-Functions of Gap Junction
The main function of gap junctions is to connect cells together so that molecules may pass from one cell to other.
This allows for cell-to-cell communication.
-Cell Signaling
Cell signaling is the process of cellular communication within the body. The binding of extracellular signaling molecules to their receptors
-Modes of cell-cell signaling
1.Direct cell-cell signaling
2. Signaling by secreted molecule
a.Endocrine signaling:
-E. g. hormones produced by endocrine glands including pituitary, pancreas, adrenal, parathyroid glands etc.
b.Paracrine signaling:
-E.g. action of neurotransmitters in carrying signals between nerve cells at a synapse.
c.Autocrine signaling:
-When interleukin-1 is produced in response to external stimuli, it can bind to cell-surface receptors on the same cell that produced it.
d.Synaptic signaling:
-Types of signaling molecules
a.Nitric oxide
b.Carbon monoxide
c.Neurotransmitter
d.Peptide hormone
-Intracellular signaling pathway activated by an extracellular signal molecule
power point presentation on the topic cellular level of organization from unit first of subject human anatomy and physiology I for first year B.PHARM it is useful for the student to study easily and find out the material easily for their study it is also useful for techers
Describe 3 functions of the cellular membrane and how are these func.pdffootworld1
Describe 3 functions of the cellular membrane and how are these functions accomplished by the
chemical make up of the membrane.
Solution
The main functions of the cell membrane are:to maintain the physical integrity of the cell,that is
to mechanically enclose the contents of the cell,also to control the movement of particles e.g.
ions or molecules,into and out of the cell.It also isolates the cytoplasm from the external
environment.
The hydrophilic head and hydrophobic tails of the phospholipid molecules that form the
phospholipid bilayer of the cell membrane forming its physical/mechanical structure.The ion
channels responsible for the selective permeability of the cell membrane.Membrane pumps that
enable active transport of specific molecules across the cell membrane.Carrier proteins and
receptor proteins that transport specific substance across the cell membrane and receive
(chemical) signals from outside the cell that tell the cell to take a specific
action,respectively.Cholesterol molecules and carbohydrate chains that support the structure of
the membrane and its attachment to other tissues,respectively.Surface protein markers that
identify the cell.Membrane proteins acts as a recptor to combine with specific substance such as
hormones while some form narrow passage ways or channels through which various molecules
and ions can cross the cell membrane.Enzymatic proteins carry out metabolic reactions..
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Sérgio Sacani
We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest
imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters
spanning 0.4−0.9µm) and novel JWST images with 14 filters spanning 0.8−5µm, including 7 mediumband filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data
at > 2.3µm to construct an ultradeep image, reaching as deep as ≈ 31.4 AB mag in the stack and
30.3-31.0 AB mag (5σ, r = 0.1” circular aperture) in individual filters. We measure photometric
redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts
z = 11.5 − 15. These objects show compact half-light radii of R1/2 ∼ 50 − 200pc, stellar masses of
M⋆ ∼ 107−108M⊙, and star-formation rates of SFR ∼ 0.1−1 M⊙ yr−1
. Our search finds no candidates
at 15 < z < 20, placing upper limits at these redshifts. We develop a forward modeling approach to
infer the properties of the evolving luminosity function without binning in redshift or luminosity that
marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the
impact of non-detections. We find a z = 12 luminosity function in good agreement with prior results,
and that the luminosity function normalization and UV luminosity density decline by a factor of ∼ 2.5
from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical
models for evolution of the dark matter halo mass function.
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.
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.
(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.
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.
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.
The increased availability of biomedical data, particularly in the public domain, offers the opportunity to better understand human health and to develop effective therapeutics for a wide range of unmet medical needs. However, data scientists remain stymied by the fact that data remain hard to find and to productively reuse because data and their metadata i) are wholly inaccessible, ii) are in non-standard or incompatible representations, iii) do not conform to community standards, and iv) have unclear or highly restricted terms and conditions that preclude legitimate reuse. These limitations require a rethink on data can be made machine and AI-ready - the key motivation behind the FAIR Guiding Principles. Concurrently, while recent efforts have explored the use of deep learning to fuse disparate data into predictive models for a wide range of biomedical applications, these models often fail even when the correct answer is already known, and fail to explain individual predictions in terms that data scientists can appreciate. These limitations suggest that new methods to produce practical artificial intelligence are still needed.
In this talk, I will discuss our work in (1) building an integrative knowledge infrastructure to prepare FAIR and "AI-ready" data and services along with (2) neurosymbolic AI methods to improve the quality of predictions and to generate plausible explanations. Attention is given to standards, platforms, and methods to wrangle knowledge into simple, but effective semantic and latent representations, and to make these available into standards-compliant and discoverable interfaces that can be used in model building, validation, and explanation. Our work, and those of others in the field, creates a baseline for building trustworthy and easy to deploy AI models in biomedicine.
Bio
Dr. Michel Dumontier is the Distinguished Professor of Data Science at Maastricht University, founder and executive director of the Institute of Data Science, and co-founder of the FAIR (Findable, Accessible, Interoperable and Reusable) data principles. His research explores socio-technological approaches for responsible discovery science, which includes collaborative multi-modal knowledge graphs, privacy-preserving distributed data mining, and AI methods for drug discovery and personalized medicine. His work is supported through the Dutch National Research Agenda, the Netherlands Organisation for Scientific Research, Horizon Europe, the European Open Science Cloud, the US National Institutes of Health, and a Marie-Curie Innovative Training Network. He is the editor-in-chief for the journal Data Science and is internationally recognized for his contributions in bioinformatics, biomedical informatics, and semantic technologies including ontologies and linked data.
2. Functions of membranes Figure 7-2
Define the boundaries of the cell and its
organelles and act as permeability barrier.
They serve as sites for specific
biochemical functions such as electron
transport during mitochondrial respiration.
Provide for and regulate transport
processes.
2
Cell Biology, lecture 6
3. Functions of membranes Figure 7-2
Cell Biology, lecture 6 3
Contain protein receptors needed to
detect external signals.
Provide mechanisms for cell-cell
contact, adhesion and communication.
5. Functions of membranes; boundaries
and permeability
membrane defines outermost part of living cell
a) Separates physically cell from environment
b) Permeability barrier
c) w/o membranes, important stuff drifts away
d) Must maintain appropriate concentrations of
molecules in smaller volumes
5
Cell Biology, lecture 6
6. e) Compartmentalize functions, Isolate
incompatible reactions
eg: lysosomes contain hydrolytic enzymes not
compatible with other macromolecules
6
Cell Biology, lecture 6
membrane defines outermost part
of living cell
Some proteins in membranes act as
enzymes???? Examples
7. Membranes are sites of specific
functions
eg: reactions of oxidative e-transport and
phosphorylation found only
7
reactions of
photosynthetic
electron transport and
photophosphorylation
found only in the
thylakoid membranes
of chloroplast
Cell Biology, lecture 6
8. Plasma membrane interacts with other cells .
Cells must recognize other cells : immune
response to foreign cells.
receives communications from other cells
chemical communications = hormones
electrical communications = nerve impulse
mechanical communications = adhesion
cells transmit communication
role in cell communication and recognition
Cell Biology, lecture 6 8
9. 9
Gap junctions (also called communicating junctions) provide
cytoplasmic channels from one cell to an adjacent cell. Gap junctions
consist of special membrane proteins that surround a pore through
which ions, sugars, amino acids, and other small molecules may
pass. Gap junctions are necessary for communication between cells
in many types of tissues, including heart muscle and animal
embryos. Cell Biology, lecture 6
10. At tight junctions, the membranes of neighboring cells are very tightly
pressed against each other, bound together by specific proteins.
Forming continuous seals around the cells, tight junctions prevent
leakage of extracellular fluid across a layer of epithelial cells.
Cell Biology, lecture 6 10
11. Cell Biology, lecture 6 11
Desmosomes (also called anchoring junctions) function like
rivets, fastening cells Together into strong sheets. Intermediate
Filaments made of sturdy keratin proteins Anchor desmosomes
in the cytoplasm.
