A membrane protein is a protein molecule that is attached to, or associated with the membrane of a cell or an organelle.
More than half of all proteins interact with membranes.
A membrane protein is a protein molecule that is attached to, or associated with the membrane of a cell or an organelle.
More than half of all proteins interact with membranes.
Structure and function of plasma membrane 2ICHHA PURAK
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The presentation consists of 72 slides,describes following heads
DEFINITION : STRUCTURE OF PLASMA MEMBRANE
COMPONENTS OF PLASMA MEMBRANE ( (BIOCHEMICAL PROPERTIES)
LIPID BILAYER
PROTEINS
CARBOHYDRATES
CHOLESTEROL
MODELS EXPLAINING STRUCTURE OF BIO MEMBRANE
FLUID MOSAIC MODEL
MOBILITY OF MEMBRANE
GLYCOCALYX : GLYCOPROTEINS AND GLYCOLIPIDS
TRANSPORT OF IONS AND MOLECULES ACROSS PLASMA MEMBRANE
FUNCTIONS OF PLASMA MEMBRANE
DIVERSITY OF CELL MEMBRANES
SITE OF ATPASE ION CARRIER CHANNELS AND PUMPS-RECEPTORS
Cell is the smallest structural and functional unit in the body of living
organism and micro-organism. Cell has a Cell membrane in its outer most
part in case of animals and cell wall for plant and for plants, cell membrane
is present under the cell wall. Cell membrane has a scientific structure. So,
many scientists gives description about the structure of cell membrane like
Sandwich Model, Unit Membrane model and Fluid Mosaic Model. But,
the Fluid Mosaic Model is widely acceptable.
Structure and function of plasma membrane 2ICHHA PURAK
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The presentation consists of 72 slides,describes following heads
DEFINITION : STRUCTURE OF PLASMA MEMBRANE
COMPONENTS OF PLASMA MEMBRANE ( (BIOCHEMICAL PROPERTIES)
LIPID BILAYER
PROTEINS
CARBOHYDRATES
CHOLESTEROL
MODELS EXPLAINING STRUCTURE OF BIO MEMBRANE
FLUID MOSAIC MODEL
MOBILITY OF MEMBRANE
GLYCOCALYX : GLYCOPROTEINS AND GLYCOLIPIDS
TRANSPORT OF IONS AND MOLECULES ACROSS PLASMA MEMBRANE
FUNCTIONS OF PLASMA MEMBRANE
DIVERSITY OF CELL MEMBRANES
SITE OF ATPASE ION CARRIER CHANNELS AND PUMPS-RECEPTORS
Cell is the smallest structural and functional unit in the body of living
organism and micro-organism. Cell has a Cell membrane in its outer most
part in case of animals and cell wall for plant and for plants, cell membrane
is present under the cell wall. Cell membrane has a scientific structure. So,
many scientists gives description about the structure of cell membrane like
Sandwich Model, Unit Membrane model and Fluid Mosaic Model. But,
the Fluid Mosaic Model is widely acceptable.
Transport mechanisms and their models.JyotiBishlay
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It encloses a brief understanding of transportation, its models and different processes likewise, Active and passive transport and their respective mechanisms, i.e. diffusion, osmosis, exocytosis, aquaporins etc.
This presentation include different kind of transport mechanism of different material inside the cell and outside the cell including Passive transport and Active transport mechenism.
This topic contains Gametogenesis- oogenesis and spermatogenesis, ovulation, fertilization, development of fertilized ovum/ zygote, implantation, development of decidua, chorion and chorionic villi, development of inner cell mass.
This topic includes menstruation:- its definition, anatomical aspects- follicular growth and atresia, germ cells, premodial follicle; menstrual cycle/ ovarian cycle:- definition, phases- recruitment of groups of follicles (premature phase), selection of dominant follicle and its maturation, ovulation, follicular atresia; Endometrial cycle:- division of endometrium- basal zone, functional zone and its phases- stage of regeneration, stage of proliferation, secretory phase, menstrual phase, mechanism of menstrual bleeding, role of prostaglandins, hormones in relation to ovarian and menstrual cycle, ovulation, luteal-follicular shift, menstrual symptoms, menstrual hygiene, anovular menstruation, artificial postponement; cervical cycle, vaginal cycle and general changes in follicular and luteal phase.
This topic includes difference between female and male pelvis, various pelvis types, general description of pelvis bones, division of pelvis, landmarks of pelvis, plane, axis, sacral angle, diameters of inlet, cavity and outlet.
This topic includes Introduction for analgesia and anesthesia used in obstetrics, maternal risk factors for anesthesia, anatomical and physiological considerations, analgesia during labour and delivery, sedatives and analgesia, opioid analgesics, combination of narcotics and antiemetics, inhalation methods, commonly used local anesthesia in obstetrics, spinal anesthesia, infiltration anesthesia, patient controlled anesthesia, psychoprophylaxis, general anesthesia for cesarean section, complication of general anesthesia and its management.
This topic includes Introduction, common side effects from maternal medications on infants, guidelines for medication during lactation, effects of various medications on lactation and neonates
This topic contains anticonvulsants used in obstetrics such as magnasium sulphate, diazepam, phenytoin and anticoagulants such as heparin and warfarin.
It is from biochemistry subject and continuation of previous topic from organization of matter. This topic contains definition of Chemistry, Matter, Mass, Weight. Description of physical state of matter and chemical structure of matter.
link for previous topic: organization of matter- important terms
https://www.slideshare.net/priyankagohil10/organization-of-matter-important-terms-237314150
Vital statistics related to maternal health in indiaPriyanka Gohil
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This topic contains introduction of vital statistics, list of important statistics, birth rate, death rate, specific death rates, infant mortality rate, neonatal mortality rate, under five mortality rate, maternal mortality rate (detailed), perinatal mortality rate (detailed), expectation of life, general fertility rate and still births.
This topic contains Meaning and definitions of midwifery, obstetrics, obstetrical nursing, midwife, scope of midwifery, basic competencies of a midwife, history of midwifery in nursing and development of maternity services in India.
This topic contains definition, instruments, indications, contraindications, prerequisites, advantages, procedure, complications and hazards of ventouse or vaccum delivery.
Presentation on this topic is available on link đ
https://youtu.be/d_JgNiYv7eU
This topic contains detail about genital prolapse in pregnancy, It's definition, incidence, types, stages, causes, risk factors, clinical features, effect of prolapse, effect on pregnancy, effect during labour and puerperium, prevention, treatment and nursing management during pregnancy, labour and puerperium.
This topic contains definition, incidence, varieties, causes, risk factors, dangers, diagnosis, prognosis, prevention and management of inversion of uterus.
This topic contains detailed description regarding Normal puerperium, it's definition, duration, phases, involution of uterus and other pelvic organs, lochia, general physiological changes of puerperium, lactation, management of normal puerperium, management of ailments and postnatal care.
This topic contains detailed description about labour, its definition, date of onset of labour, calculations of date of delivery, causes of onset of labour, physiology of normal labour, and events, clinical course and management of each stages of labour.
Report Back from SGO 2024: Whatâs the Latest in Cervical Cancer?bkling
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Are you curious about whatâs new in cervical cancer research or unsure what the findings mean? Join Dr. Emily Ko, a gynecologic oncologist at Penn Medicine, to learn about the latest updates from the Society of Gynecologic Oncology (SGO) 2024 Annual Meeting on Womenâs Cancer. Dr. Ko will discuss what the research presented at the conference means for you and answer your questions about the new developments.
Tom Selleck Health: A Comprehensive Look at the Iconic Actorâs Wellness Journeygreendigital
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Tom Selleck, an enduring figure in Hollywood. has captivated audiences for decades with his rugged charm, iconic moustache. and memorable roles in television and film. From his breakout role as Thomas Magnum in Magnum P.I. to his current portrayal of Frank Reagan in Blue Bloods. Selleck's career has spanned over 50 years. But beyond his professional achievements. fans have often been curious about Tom Selleck Health. especially as he has aged in the public eye.
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Introduction
Many have been interested in Tom Selleck health. not only because of his enduring presence on screen but also because of the challenges. and lifestyle choices he has faced and made over the years. This article delves into the various aspects of Tom Selleck health. exploring his fitness regimen, diet, mental health. and the challenges he has encountered as he ages. We'll look at how he maintains his well-being. the health issues he has faced, and his approach to ageing .
Early Life and Career
Childhood and Athletic Beginnings
Tom Selleck was born on January 29, 1945, in Detroit, Michigan, and grew up in Sherman Oaks, California. From an early age, he was involved in sports, particularly basketball. which played a significant role in his physical development. His athletic pursuits continued into college. where he attended the University of Southern California (USC) on a basketball scholarship. This early involvement in sports laid a strong foundation for his physical health and disciplined lifestyle.
Transition to Acting
Selleck's transition from an athlete to an actor came with its physical demands. His first significant role in "Magnum P.I." required him to perform various stunts and maintain a fit appearance. This role, which he played from 1980 to 1988. necessitated a rigorous fitness routine to meet the show's demands. setting the stage for his long-term commitment to health and wellness.
Fitness Regimen
Workout Routine
Tom Selleck health and fitness regimen has evolved. adapting to his changing roles and age. During his "Magnum, P.I." days. Selleck's workouts were intense and focused on building and maintaining muscle mass. His routine included weightlifting, cardiovascular exercises. and specific training for the stunts he performed on the show.
Selleck adjusted his fitness routine as he aged to suit his body's needs. Today, his workouts focus on maintaining flexibility, strength, and cardiovascular health. He incorporates low-impact exercises such as swimming, walking, and light weightlifting. This balanced approach helps him stay fit without putting undue strain on his joints and muscles.
Importance of Flexibility and Mobility
In recent years, Selleck has emphasized the importance of flexibility and mobility in his fitness regimen. Understanding the natural decline in muscle mass and joint flexibility with age. he includes stretching and yoga in his routine. These practices help prevent injuries, improve posture, and maintain mobilit
Prix Galien International 2024 Forum ProgramLevi Shapiro
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June 20, 2024, Prix Galien International and Jerusalem Ethics Forum in ROME. Detailed agenda including panels:
- ADVANCES IN CARDIOLOGY: A NEW PARADIGM IS COMING
- WOMENâS HEALTH: FERTILITY PRESERVATION
- WHATâS NEW IN THE TREATMENT OF INFECTIOUS,
ONCOLOGICAL AND INFLAMMATORY SKIN DISEASES?
- ARTIFICIAL INTELLIGENCE AND ETHICS
- GENE THERAPY
- BEYOND BORDERS: GLOBAL INITIATIVES FOR DEMOCRATIZING LIFE SCIENCE TECHNOLOGIES AND PROMOTING ACCESS TO HEALTHCARE
- ETHICAL CHALLENGES IN LIFE SCIENCES
- Prix Galien International Awards Ceremony
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Ve...kevinkariuki227
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TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
Knee anatomy and clinical tests 2024.pdfvimalpl1234
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This includes all relevant anatomy and clinical tests compiled from standard textbooks, Campbell,netter etc..It is comprehensive and best suited for orthopaedicians and orthopaedic residents.
New Drug Discovery and Development .....NEHA GUPTA
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The "New Drug Discovery and Development" process involves the identification, design, testing, and manufacturing of novel pharmaceutical compounds with the aim of introducing new and improved treatments for various medical conditions. This comprehensive endeavor encompasses various stages, including target identification, preclinical studies, clinical trials, regulatory approval, and post-market surveillance. It involves multidisciplinary collaboration among scientists, researchers, clinicians, regulatory experts, and pharmaceutical companies to bring innovative therapies to market and address unmet medical needs.
Title: Sense of Smell
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the primary categories of smells and the concept of odor blindness.
Explain the structure and location of the olfactory membrane and mucosa, including the types and roles of cells involved in olfaction.
Describe the pathway and mechanisms of olfactory signal transmission from the olfactory receptors to the brain.
Illustrate the biochemical cascade triggered by odorant binding to olfactory receptors, including the role of G-proteins and second messengers in generating an action potential.
Identify different types of olfactory disorders such as anosmia, hyposmia, hyperosmia, and dysosmia, including their potential causes.
Key Topics:
Olfactory Genes:
3% of the human genome accounts for olfactory genes.
400 genes for odorant receptors.
Olfactory Membrane:
Located in the superior part of the nasal cavity.
Medially: Folds downward along the superior septum.
Laterally: Folds over the superior turbinate and upper surface of the middle turbinate.
Total surface area: 5-10 square centimeters.
Olfactory Mucosa:
Olfactory Cells: Bipolar nerve cells derived from the CNS (100 million), with 4-25 olfactory cilia per cell.
Sustentacular Cells: Produce mucus and maintain ionic and molecular environment.
Basal Cells: Replace worn-out olfactory cells with an average lifespan of 1-2 months.
Bowmanâs Gland: Secretes mucus.
Stimulation of Olfactory Cells:
Odorant dissolves in mucus and attaches to receptors on olfactory cilia.
Involves a cascade effect through G-proteins and second messengers, leading to depolarization and action potential generation in the olfactory nerve.
Quality of a Good Odorant:
Small (3-20 Carbon atoms), volatile, water-soluble, and lipid-soluble.
Facilitated by odorant-binding proteins in mucus.
Membrane Potential and Action Potential:
Resting membrane potential: -55mV.
Action potential frequency in the olfactory nerve increases with odorant strength.
Adaptation Towards the Sense of Smell:
Rapid adaptation within the first second, with further slow adaptation.
Psychological adaptation greater than receptor adaptation, involving feedback inhibition from the central nervous system.
Primary Sensations of Smell:
Camphoraceous, Musky, Floral, Pepperminty, Ethereal, Pungent, Putrid.
Odor Detection Threshold:
Examples: Hydrogen sulfide (0.0005 ppm), Methyl-mercaptan (0.002 ppm).
Some toxic substances are odorless at lethal concentrations.
Characteristics of Smell:
Odor blindness for single substances due to lack of appropriate receptor protein.
Behavioral and emotional influences of smell.
Transmission of Olfactory Signals:
From olfactory cells to glomeruli in the olfactory bulb, involving lateral inhibition.
Primitive, less old, and new olfactory systems with different path
Recomendaçþes da OMS sobre cuidados maternos e neonatais para uma experiência pós-natal positiva.
Em consonância com os ODS â Objetivos do Desenvolvimento SustentĂĄvel e a EstratĂŠgia Global para a SaĂşde das Mulheres, Crianças e Adolescentes, e aplicando uma abordagem baseada nos direitos humanos, os esforços de cuidados pĂłs-natais devem expandir-se para alĂŠm da cobertura e da simples sobrevivĂŞncia, de modo a incluir cuidados de qualidade.
Estas diretrizes visam melhorar a qualidade dos cuidados pĂłs-natais essenciais e de rotina prestados Ă s mulheres e aos recĂŠm-nascidos, com o objetivo final de melhorar a saĂşde e o bem-estar materno e neonatal.
Uma âexperiĂŞncia pĂłs-natal positivaâ ĂŠ um resultado importante para todas as mulheres que dĂŁo Ă luz e para os seus recĂŠm-nascidos, estabelecendo as bases para a melhoria da saĂşde e do bem-estar a curto e longo prazo. Uma experiĂŞncia pĂłs-natal positiva ĂŠ definida como aquela em que as mulheres, pessoas que gestam, os recĂŠm-nascidos, os casais, os pais, os cuidadores e as famĂlias recebem informação consistente, garantia e apoio de profissionais de saĂşde motivados; e onde um sistema de saĂşde flexĂvel e com recursos reconheça as necessidades das mulheres e dos bebĂŞs e respeite o seu contexto cultural.
Estas diretrizes consolidadas apresentam algumas recomendaçþes novas e jĂĄ bem fundamentadas sobre cuidados pĂłs-natais de rotina para mulheres e neonatos que recebem cuidados no pĂłs-parto em unidades de saĂşde ou na comunidade, independentemente dos recursos disponĂveis.
Ă fornecido um conjunto abrangente de recomendaçþes para cuidados durante o perĂodo puerperal, com ĂŞnfase nos cuidados essenciais que todas as mulheres e recĂŠm-nascidos devem receber, e com a devida atenção Ă qualidade dos cuidados; isto ĂŠ, a entrega e a experiĂŞncia do cuidado recebido. Estas diretrizes atualizam e ampliam as recomendaçþes da OMS de 2014 sobre cuidados pĂłs-natais da mĂŁe e do recĂŠm-nascido e complementam as atuais diretrizes da OMS sobre a gestĂŁo de complicaçþes pĂłs-natais.
O estabelecimento da amamentação e o manejo das principais intercorrências Ê contemplada.
Recomendamos muito.
Vamos discutir essas recomendaçþes no nosso curso de pós-graduação em Aleitamento no Instituto Ciclos.
Esta publicação sĂł estĂĄ disponĂvel em inglĂŞs atĂŠ o momento.
Prof. Marcus Renato de Carvalho
www.agostodourado.com
NVBDCP.pptx Nation vector borne disease control programSapna Thakur
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NVBDCP was launched in 2003-2004 . Vector-Borne Disease: Disease that results from an infection transmitted to humans and other animals by blood-feeding arthropods, such as mosquitoes, ticks, and fleas. Examples of vector-borne diseases include Dengue fever, West Nile Virus, Lyme disease, and malaria.
Lung Cancer: Artificial Intelligence, Synergetics, Complex System Analysis, S...Oleg Kshivets
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RESULTS: Overall life span (LS) was 2252.1Âą1742.5 days and cumulative 5-year survival (5YS) reached 73.2%, 10 years â 64.8%, 20 years â 42.5%. 513 LCP lived more than 5 years (LS=3124.6Âą1525.6 days), 148 LCP â more than 10 years (LS=5054.4Âą1504.1 days).199 LCP died because of LC (LS=562.7Âą374.5 days). 5YS of LCP after bi/lobectomies was significantly superior in comparison with LCP after pneumonectomies (78.1% vs.63.7%, P=0.00001 by log-rank test). AT significantly improved 5YS (66.3% vs. 34.8%) (P=0.00000 by log-rank test) only for LCP with N1-2. Cox modeling displayed that 5YS of LCP significantly depended on: phase transition (PT) early-invasive LC in terms of synergetics, PT N0âN12, cell ratio factors (ratio between cancer cells- CC and blood cells subpopulations), G1-3, histology, glucose, AT, blood cell circuit, prothrombin index, heparin tolerance, recalcification time (P=0.000-0.038). Neural networks, genetic algorithm selection and bootstrap simulation revealed relationships between 5YS and PT early-invasive LC (rank=1), PT N0âN12 (rank=2), thrombocytes/CC (3), erythrocytes/CC (4), eosinophils/CC (5), healthy cells/CC (6), lymphocytes/CC (7), segmented neutrophils/CC (8), stick neutrophils/CC (9), monocytes/CC (10); leucocytes/CC (11). Correct prediction of 5YS was 100% by neural networks computing (area under ROC curve=1.0; error=0.0).
CONCLUSIONS: 5YS of LCP after radical procedures significantly depended on: 1) PT early-invasive cancer; 2) PT N0--N12; 3) cell ratio factors; 4) blood cell circuit; 5) biochemical factors; 6) hemostasis system; 7) AT; 8) LC characteristics; 9) LC cell dynamics; 10) surgery type: lobectomy/pneumonectomy; 11) anthropometric data. Optimal diagnosis and treatment strategies for LC are: 1) screening and early detection of LC; 2) availability of experienced thoracic surgeons because of complexity of radical procedures; 3) aggressive en block surgery and adequate lymph node dissection for completeness; 4) precise prediction; 5) adjuvant chemoimmunoradiotherapy for LCP with unfavorable prognosis.
Ocular injury ppt Upendra pal optometrist upums saifai etawah
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Structure & function of cell membrane
1.
2. ďThe Plasma membrane or the cell
membrane is a thin, biological
membrane present in all eukaryotic and
prokaryotic cells that forms a boundary
between the cell and its environment
and regulating the flow of materials in
to and out of cell.
3.
4. ďThe cells maintain an approprite
amount of all molecules within them to
function effectively.
ďSo, this plasma membrane acts as a
semi permeable membrane allowing
the entry and exits of certain materials.
ďIt is like a gaurd at a gated community
who inspects those who enter and
leave, to make sure that only people
and things needed in the community
are there.
5.
6. ďThe cell membrane was discovered by
a Swiss botanist Carl Naegeli and C
Carmer in 1855.
ďDespite the existance microscopes
from 1600, no-one thought that the cell
membrane existed because all they
could see was the cell wall.
ďCarl Naegeli and Carmer noted that the
surface of the cell was not continuous
and that it was impermeable to
pigments added to the solution around
the cell.
7. ďThey also found that the photoplasmic
surface was more dense and viscous
when compared to the cytoplasm.
ďThey called this surface as the plasma
membrane.
8. ⢠The first insight into chemical nature of
the membrane was obtained by Ernst
Overton in 1890s.
⢠He knew that the nonpolar solutes
dissolved very easily in the non polar
solvents than polar solvents and the
polar solutes had opposite solubility.
⢠So, he realised that the substances
entering the cell had to be dissolved in
the outer boundary of cell is due to
lipids.
9. ⢠Irvin Langmuir, in 1917, during his
research in nature of oil film, found that
the membrane was made of monolayer
of lipids and they were arranged
vertically with hydrocarbon chains
away from water and carboxyl groups in
contact with the surface of water.
⢠This finding was a key in understanding
the lipid bilayer and cell membrane
structure.
10. ⢠The two Dutch scientists E. Gorter and
F. Grendel in 1925 were the first to find
that the membrane was made of two
layers of lipids ( lipid bilayer) with
hydrophilic heads and hydrophobic
tails, but they could not explain about
the solute permeability or the surface
tension.
11. ⢠In 1935, Hugh Davson and James
Danielle proposed that the membrane
is made of lipid bilayer and on both
outer and inner surface there was a
lining of globular proteins.
⢠In 1950 they found that selective
permeability was because of the
presence of protein lined pores within
the lipid bilayer, which allowed the
passage of polar solutes and ions into
and out of cell.
12. ⢠It was in 1972 that S. Jonathan singer
and Garth Nicholson proposed the
Fluid Mosaic Model which is
considered as the central dogma of
membrane biology.
⢠It describes the structure of cell
membrane as a lipid bilayer with
proteins embeded in it and which is
free to move laterally within the
membrane.
13. ⢠It was first proposed by S. J. Singer
and G. Nicholson in 1972 to describe
the structure of the plasma membrane.
⢠The fluid mosaic model describes the
plasma membrane as that which
surrounds the cell, which is made up of
two layers of phospholipids and at
body temperature is fluid.
14. ⢠Embedded within this membrane is
variety of protein molecules that acts
as channels and pumps.
⢠It contains carbohydrates, cholesterol
and other lipids.
⢠The protein and other substances such
as cholesterol become embedded in
the lipid bilayer, giving the membrane
the look of the mosaic.
15. ⢠Since the plasma membrane has the
consistency of vegetable oil at body
temperature, the proteins and other
substances are able to move freely
laterally.
⢠That is why the plasma membrane is
described as a fluid mosaic model.
⢠The fulid mosaic model thoery thereby
states that plasma membrane structure
is a lipid bilayer with mosaic of
proteins embedded in it and moves
freely parallel to the surface of the
membrane.
16. ⢠The fluidity of lipid bilayer was shown
by the technique of fluorescence
recovery.
⢠The fluorescent dye is used to tag the
lipids and a high density laser beam is
used to bleach the dye in a tiny spot on
the cell surface.
⢠When observed under fluorescent
microscope, it is seen that within
seconds the bleached spot became
fluorescent again.
⢠This explained the lateral diffusion of
phospholipids.
25. ⢠To maintain cell functions, many
biological molecules enter and leave
the cell.
⢠All materials that the cell gets from its
environment or sends to the
environment, Passes through this
semipermeable plasma membrane.
⢠Membrane transport is esseltial for
cellular life.
26.
27.
28. ďśChemicals that can pass through the
membrane are:-
ď§Water
ď§Carbon dioxide
ď§Oxygen
ď§Small polar molecules such as ammonia
ď§Lipids such as cholesterol
ďśChemicals that cannot pass through the
membrane are:-
ď§All ions including hydrogen ions
ď§Large polar molecules like glucose
ď§Aminoacids
ď§Macromolecules such as proteins,
polysachharides
29.
30.
31.
32.
33. ď§Small uncharged polar molecules like
water, urea, ethanol, have an exceptions as
they can diffuse through the lipid bilayer.
ďśThere are certain factors that affect the
diffusion across the cell membrane:
ď§Size of solute
ď§Solute polarity
ď§Temperature
ď§Lipid solubility
34.
35.
36.
37. ď§The substances to be moved binds to these
proteins and this complex will bind to a
receptor site and then be transported across
the membrane.
ď§This process does not require energy as
molecules are moving down the concentration
gradient.
ď§Polar and charged solutes such as glucose,
fructose, galactose and some vitamins are
transported by facilitated diffusion.
38.
39. ď§A solution with lower solute concentration
than inside of cell is called hypotonic
solution.
ď§It causes the cell to swell and burst as it
causes movement of water to inside of cell.
ď§A solution with higher solute concentration
than inside of cell is called hypertonic
solution.
ď§This causes osmosis of water from inside of
cell to outside leading to shrinkage of cell.
40.
41. Eg, transportation of sodium out of cell and
potassium into the cell.
ďśThere are two forms of active transports:-
42. ď§ When the process uses chemical energy in
the form of ATP, redox energy or photon
energy to transport substances across the
membrane, it is called primary active
transport.
ď§ The energy is derived directly from the
breaskdown of ATP or some other high
energy phosphate compounds.
ď§ The proteins act as pumps to transport
ions.
43. ď§ Most of the enzymes that perform this
transport are transmembrane ATP-ase.
ď§ A primary ATP-ase which is universal to all
animal cells is sodium- potassium pump
which maintains the cell potential.
44. ď§ When the process uses electrochemical
gradient to transport substances, it is called
secondary active transport.
ď§ Here the energy is derived secondarily from
energy that has been stored in the form of
ionic concentration differences between the
two sides of a membrane, created in the first
place by primary active transport.
45. ď§ The pore forming proteins act as channels
across the cell membrane for transporting
substances.
ď§ The energy stored in Na+
, H+
concentration
gradient is used to transport other solutes
or ions.
46.
47.
48.
49. ď This pump is called a P-type ion pump
because the ATP interactions phosphorylate
the transport protein and causes a change in
its confirmation.
50. ď It is an antiporter enzyme located in the
plasma membrane of the cells, which
transport potassium ions from the extra
cellular fluid to the cytoplasm and sodium
ions from the cytoplasm to outside of the
cell.
ď The pump is present in all the cells of the
body, and it is responsible for maintaining
the sodium and potassium concentration
difference across the cell membrane as well
as establishing a negative electrolyte
potential inside the cells.
51. ď It was discovered by Danish scientist Jens
Christian Skou in 1950.
ď It was investigated by the passage of
radioactively labelled ions across the plasma
membrane.
ď It showed that the sodium and potassium
ions on both sides were interdependent
which suggested that the same carrier
protein transported both the ions.
ď This carrier protein is a complex of two
globular proteins namely Îąsubunit
andβsubunit which has receptor sites for
transport of three sodium ions out of cell for
every two potassium ions pumped in.
52.
53. 4. Now, two potassium ions binds at the
receptor sites present on the portion of
protein that is near to outside of the
carrier protein.
5. The ATP is then activated and the energy
released causes confirmational change in
the protein causing potassium ions to be
released into the cell.
6. The returns to its first stage-steady to
receive new sodium ions, so that the
cycle can begin all over again.
54.
55.
56.
57.
58. ⢠It is the movement of substances out of the
cell in the form of the secondary vesicles,
which fuses with the plasma membrane and
then releases its contents into the
extracellular fluid.
⢠It is important in the expulsion of waste
materials out of the cell, and the secretion of
enzymes and hormones.
⢠Neurotransmitters, digestive enzymes,
hormones are released from cell by
exocytosis.
59. ⢠It is the movement of substances from extra
cellular fluid into cell in the form of vesicles.
⢠The large polar molecules that cannot pass
through the plasma membrane enters the cell
by endocytosis.
⢠This process requires energy in the form of
ATP.
66. ď It attracts the substance tobe absorbed
by forming a membrane depression or a
coated pit on the membrane.
ď When sufficient molecules have been
attracted, the pocket will pinch off
forming a coated vesicle in the
cytoplasm.
ď Inside the cytoplams the vesicle shed off
their coats and then fuse with other
membrane bound structures releasing
their contents.
ď E.g, Uptake of iron, cholesterol by the
cell occurs by receptor mediated
endocytosis.
67.
68. ⢠Cell junction is a type of structure that
exists in the tissues and organs.
⢠It is a multi-protein complex that
occurs between the neighbouring cells
which helps in communication between
them.
⢠There occurs a specialized
modification of the plasma membrane
at the point of contact, forming a
function or a bridge.
69.
70. ⢠Also known as occluding junction, is
the closest contact between adjacent
cells providing a tight seal, preventing
the leakage of mlecules cross the cells.
⢠It is found just beneath the apical
region (portion of cell exposed to
lumen is apical surface) of cell around
the cell circumference.
71. ⢠Since they are tight seals limiting the
passage of molecules and ions, most
materials actually enter the cells by diffusion
or active transport.
⢠The tight junction is formed by proteins
called claudins and occludins which are
arranged in strands along the line of junction
creating a tight seal.
⢠It is usually seen in epithelial cells, ducts of
liver, pancreas and urinary bladder.
72.
73. ⢠These are protein complexes that occur
at cell to cell junction in epithelial and
endothelial tissues which provides
strong mechanical attachments
between adjacent cells.
⢠It is built from proteins cadherins and
catenins.
74. ⢠The cytoplasmic face of the cell has actin
filaments and these actin bundules of one
cell joins with the actin bundles of the
neighbouring cells providing a strong
mechanical attachment.
⢠The space between the neighbouring cell
membranes are about 20-25 nm.
⢠This kind of junction is seen in heart muscles
and they hold the cardiac muscles together
when it expands and contracts.
75.
76. ⢠They are specialized intracellular
channels which are brought into
intimate contact with a gap of about 2-3
nm between the adjacent cells.
⢠They directly form a connection
between the cytoplasm of adjacent cell
so that molecules, ions, electrical
impulse pass directly from cell to cell.
77. ⢠The intracellular channels are like hollow
cylinders and they are called as connexons.
⢠These connexons are madeup of proteins
called connexin.
⢠The two adjcent connexons form a
hydrophilic channel of 3 nm diameter and it
is through this channel that the ions and
molecule pass.
⢠Gap junction is seen in muscles and nerves.
In heart tissue helps in regular heart beat, in
brain it is seen in cerebellum and it helps in
muscular activity.
78.
79.
80. ⢠These are intracellular junctions which form
a strong adhesion between adjacent cells.
⢠It enables the cell to resist any stress.
⢠The intermediate filaments (presents
intracellularly) of adjacents cells join with
eachother to form the strong adhesions so
that they can function as a single unit.
⢠They are usually seen in orgns subjected to
mechanical stress like skin, heart and neck
of uterus
81.
82. ⢠It is a type of cell junction seen in plants.
⢠These are microscopic channels that connect
the cytoplasm of adjacent cells.
⢠It penetrates through the cell wall and it
provides an easy route for movement of ions,
small molecules like RNA and proteins.