This document discusses the structure and functions of the cell membrane. It is composed of a phospholipid bilayer with integral and peripheral proteins. The membrane regulates the movement of substances via passive and active transport mechanisms. Passive transport includes simple diffusion, facilitated diffusion, filtration, and osmosis which move substances down their concentration gradients. Active transport requires energy and transports substances against their gradients using pumps like the sodium-potassium pump.
'Basic mechanisms of membrane transport is the topic of general pharmacology.
Introduction- Membrane Transport
Plasma Membrane
Lipid solubility in membrane permeation
Transporters Versus Channels
Mechanisms of Transport
Passive Diffusion
Relationship between Molecular weight and Diffusion
Carrier mediated Transport
Facilitated Diffusion
Active Transport
Primary Active Transport
P type- Na+ K+-ATPase
Secondary Active transport- Symport, Antiport
Intestinal Transporters with e.g
Vesicular Transport-Exocytosis, Endocytosis-Phagocytosis,Pinocytosis
Pore (Convective) Transport
Ion Pair Formation
'Basic mechanisms of membrane transport is the topic of general pharmacology.
Introduction- Membrane Transport
Plasma Membrane
Lipid solubility in membrane permeation
Transporters Versus Channels
Mechanisms of Transport
Passive Diffusion
Relationship between Molecular weight and Diffusion
Carrier mediated Transport
Facilitated Diffusion
Active Transport
Primary Active Transport
P type- Na+ K+-ATPase
Secondary Active transport- Symport, Antiport
Intestinal Transporters with e.g
Vesicular Transport-Exocytosis, Endocytosis-Phagocytosis,Pinocytosis
Pore (Convective) Transport
Ion Pair Formation
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.
(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.
Comparing Evolved Extractive Text Summary Scores of Bidirectional Encoder Rep...University of Maribor
Slides from:
11th International Conference on Electrical, Electronics and Computer Engineering (IcETRAN), Niš, 3-6 June 2024
Track: Artificial Intelligence
https://www.etran.rs/2024/en/home-english/
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.
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.
Richard's aventures in two entangled wonderlandsRichard 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.
Toxic effects of heavy metals : Lead and Arsenicsanjana502982
Heavy metals are naturally occuring metallic chemical elements that have relatively high density, and are toxic at even low concentrations. All toxic metals are termed as heavy metals irrespective of their atomic mass and density, eg. arsenic, lead, mercury, cadmium, thallium, chromium, etc.
This presentation explores a brief idea about the structural and functional attributes of nucleotides, the structure and function of genetic materials along with the impact of UV rays and pH upon them.
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.
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.
5. Functions of cell membrane
Acts as semi permeable barrier –(selective)
oMaintains difference in composition of
ICF & ECF & fluid in various organelles
oProtects cell from toxic substances
oExcretion of waste products
oTransport of nutrients
Receives signals from the outside
Chemical signals
Electrical signals
Site for attachment to the neighboring cells
6. Transport across cell membrane
Transport Mechanisms
Passive Active
Simple diffusion
Facilitated diffusion
Filtration
Osmosis
dialysis
Primary active transport
Secondary active transport
Endo/Exocytosis
7. Methods of transport
Passive Active
Lipid bilayer
Protein
channels
Leaky channels
Gated channels
Diffusion
Simple facilitated
Osmosis Filtration
voltage gated
Ligand gated
Dialysis
8. Simple diffusion -
Movement of molecules from higher
concentration to lower concentration till
equilibrium is reached
9. .Diffusion can takes place through:
a) Lipid bilayer
i) Lipid soluble substances-
O2,Co2,alcohol, steriods etc
ii) Lipid insoluble – water (through
spaces bet lipid mol) urea, sugar
(less or no permeability)
iii) Electrolytes – impermeable
– charge on fatty acid chain
- Hydrated forms are larger
10. .
b) Protein Channels Open/leaky – Na+ channels,
K+ channels
Gated –channels open under specific conditions
Ligand gated
Na+
K+
Voltage gated
Na+,
K+
Ca++,
Mutation of ionic channels produce channelopathies –affecting
muscle and brain – paralysis or convulsions
11. Factors affecting rate of diffusion
• Lipid solubility
• Molecular size & wt.
• Temperature
• Thickness of membrane
• Surface area
• Concentration gradient
• Pressure gradient
• Electrical gradient
Molecular
Membrane related
Gradients
12. Fick’s law of diffusion –
Q α ─ ─ ─ ─
ΔC∙P∙A
MW∙ ΔX
Q = net rate of diffusion
ΔC = conc. gradient of a substance
P = permeability of membrane to the sub.
A = surface area of a membrane
MW = molecular wt. of sub.
ΔX = thickness or distance
13. II. Facilitated diffusion :
- for larger water soluble mols.
- type of passive transport
- along the conc. Gradient
- carrier mediated transport
- receptor site on one side
Mechanism
14. - Rate of transport –
Conc. gradient
velocity
Simple diffusion
Facilitated diffusion
Initially, rate is directly proportional to conc. gradient
Till it reaches ( limitation because of no. of
carrier mols. & rate of conformational change)
Hormonal regulation by changing #of carriers.
Vmax
Vmax
Vmax
15.
16. - Peculiarities of carrier mediated transport –
specificity,
competitive or noncompetitive inhibition –
phloridzin for glucose
saturation,
blocking of receptor
Vmax
-Examples – transport of glucose, amino acids,
galactose, etc. in the peripheral cells or counter
transport of Ci and HCO3 in renal tubules
17. III. Osmosis & osmotic pressure–
when two solutions of different concentrations are
separated by a semi permeable membrane
( impermeable to solute and permeable to water )
water mols. diffuse from solution having less conc. To
the sol. having higher conc.
18. Osmotic pressure is the minimum pressure
applied on the solution with high conc. which
prevents osmosis.
- depends upon total no. of particles of dissolved
solutes rather than type of the particles
Osmols or mOsmols – expresses conc. of
osmotically active particles
1 osmol = total no. of particles in gram molecular
wt. of non diffusible substance per kg. of water
19. Isotonic, hypotonic & hypertonic solutions
Isotonic solution – fluids having osmolarity
same as that of plasma ( 290 mOsmols ) . Red
cells suspended in such solution do not shrink
or swell. ( 0.9 % NaCl, 5% glucose )
In Hypotonic soln. RBCs swell and hemolysis
may occur.
In hypertonic solution RBCs shrink because
water moves out.
Applied -
20. Gibbs – Donnan Equilibrium
Explains difference in the conc. of
diffusible ions in two compartments separated by
semi permeable membrane, when one
compartment contains non diffusible ions
Na +
Cl -
Pr -
A B
Na +
Cl -
Proteins are non
diffusible anions in A
Conc. Of Na + is more
in A as compared to B
22. Explaination –
1) All the solutions are electrically neutral.
( total no. of anions = total no. of cations )
2) Product of diffusible cations and an
anions in both the compartment is equal.
( Na+
A x Cl-
A = Na+
B x Cl-
B )
Applied –
In ICF conc. of diffusible K+ is more because of
presence of non diffusible Pr - and PO4
-
23. Diffusion potential or Equilibrium potential - E
Potential generated across the cell membrane in
the presence of non diffusible ions in one
compartment.
Magnitude of potential developed can be
calculated by Nernst equation.
25. IV. Filtration
Filtration is a process in which fluid along
with solutes passes through a membrane due to
difference in pressures on both sides.
e.g. Filtration at capillary
Capillary hydrostatic pressure – 28mm Hg
Interstitial fluid hydrostatic pressure - -2mm Hg
Colloidal osmotic pressure - 25mm Hg
Net Filtration pressure = 28 - (- 2 + 25) = 5 mm Hg
26. V. Dialysis –
separation of larger dissolved particles from
smaller particles
It is used for elimination of waste products in the
blood in case of renal failure.
27. Active transport
Primary active transport
Secondary active transport
Endocytosis
Pinocytosis
Phagocytosis
Exocytosis
28. Peculiarities of active transport
1) Carrier mediated transport
2) Rapid rate of transport
3) Transport takes place against electrochemical
gradient ( uphill )
4) Expenditure of energy by transport protein
which incorporates ATPase activity
30. I. Primary active transport –
Examples - Na+ - K+ pump, Ca++ pump
H+-K+ pump
- Inner surface of carrier mol. has ATPase
which is activated by attachment of specific
ions and causes hydrolysis of ATP molecule
- Energy released from ATP causes
conformational change in the carrier which
transports ions to the opposite side.
31. a) Na+ -K + pump- electrogenic pump
- Attachment of 2K+ on outer side & 3 Na+ on inner side
Activation of ATPase
Conformational change
Efflux of 3 Na+ & influx of 2K+
Creates high K+ conc. & - vity inside the cell
Helps in maintaining cell volume
3Na+
2K+
ATPa
es
32. Na-K pump is one of the major energy using
process in the body & accounts for a large part
of basal metabolism.
Regulators of Na-K pump –
- Incraesed amount of cellular Na conc.
- Thyroid hormones increase pump activity by more # of Na-K
ATPase mol
- Aldosterone also increases # of pumps
- DOPamine inhibits pump
- Insulin increases pump activity
- Oubain or Digitalis inhibits ATPase (used when weakness of
cardiac muscle –maintains Ca conc. In ICF of cardiac muscle
33. - Ca++ pump –
present in the membrane of ER,
mitochondria and cell membrane
- involves uniport carrier
- helps to maintain low Ca++conc. in ICF
34. II. Secondary active transport
Active transport depending upon conc.
gradient of Na+ from ECF to ICF created by
utilization of energy
_ carrier does not have ATPase activity
Substance is transported along with Na+
(Na increases affinity of carrier for gl.)
Na+ is transported only when glucose mol. is
attached
35. Examples – a) Reabsorption of glucose & amino
acids in PCT & Intestinal mucosa – Co-transport
mechanism
b) H+ secretion by tubular epithelium
– counter transport mechanism
c)In heart Na-K ATPase indirectly affects Ca transport. –antiport
in the membrane of cardiac muscle exchanges intracellular Ca
for extracellular Na
36. Na+
K+
Glucose
lumen
basal
Na + – K + pump on basal side
Electrochemical gradient for Na + on luminal side
Carrier mediated transport (SGLT-1)of Na+ along
with glucose ( or amino acid ) through the apical
membrane
Transport of glucose by facilitated diffusion
( GLUT-2 ) through basal side
38. Extracellular material to be tackled by
lysosomes is brought into the cell by
endocytosis
3 types
pinocytosis
Receptor
mediated
endocytosis
phagocytosis
Specialised
cells
All cells
Requires ATPase, Ca, microfilaments
40. B. Receptor mediated endocytosis – highly
selective process to import imp. specific large
molecules. Requires energy & Ca++.
Coated pit
Clathrin, actin,
myosin
e.g. endocytosis of low density
lipoproteins
e.g. endocytosis of viruses such as
hepatitis, AIDS viruses & excess iron
41. C. Phagocytosis
• Internalization of large multimolecular
particles, bacteria, dead tissues by
specialized cells e.g. certain types of
w.b.c.s ( Professional phagocytes)
• The material makes contact with the
cell membrane which then invaginates.
43. Passive transport Active transport
• No expenditure of
energy molecules
• Takes place along
conc., electrical, &
pressure gradient
• Carrier may or may
not be required
• Rate is proportional to
conc. difference
• Expenditure of energy
mol. ( ATP )
• Can take place against
conc. Gradient
• Carrier is always
required
• Rate is proportional to
availability of carrier
& energy. (Vmax)
44. Simple Diffusion Facilitated Diffusion
• Passive transport
• For small molecules
• No carrier required
• Rate of transport is
directly proportional to
conc. gradient
• Examples –
Lipid soluble –
O2, CO2, alcohol
Lipid insoluble –
urea, Na+, K+
• Passive transport
• For large molecules
• Carrier mediated
• Initially rate is
proportional to conc.
gradient till Vmax
( saturation of carriers)
• Examples –
glucose, amino acids