Cell Membrane Transport/Factors/Transport of SubstancesPharmacy Universe
The gradient consists of two parts, the electrical potential and a difference in the chemical concentration across a membrane.
In biological processes, the direction an ion moves by diffusion or active transport across a membrane is determined by the electrochemical gradient.
Generally compound moves from an area of high concentration to low concentration (or concentration gradient). All compounds permeable to the phospholipid bilayer will move this way.
This Lecture is presented by our volunteer Md Faheem Shahriar, he is from Bangladesh, he is currently perusing BS in pharmacy from China Pharmaceutical University, Nanjing and, his current topic is Cell membrane transport in this video presentation. Youtube link below:
https://www.youtube.com/watch?v=2TxBwdwLJ8E
Cell Membrane Transport/Factors/Transport of SubstancesPharmacy Universe
The gradient consists of two parts, the electrical potential and a difference in the chemical concentration across a membrane.
In biological processes, the direction an ion moves by diffusion or active transport across a membrane is determined by the electrochemical gradient.
Generally compound moves from an area of high concentration to low concentration (or concentration gradient). All compounds permeable to the phospholipid bilayer will move this way.
This Lecture is presented by our volunteer Md Faheem Shahriar, he is from Bangladesh, he is currently perusing BS in pharmacy from China Pharmaceutical University, Nanjing and, his current topic is Cell membrane transport in this video presentation. Youtube link below:
https://www.youtube.com/watch?v=2TxBwdwLJ8E
Topic : Membrane transport: Transport of water, ion and biomoleculesAJAYSOJITRA6
TOPIC WILL BE CONSIDER…..
TRANSPORT MECHANISM ; TYPES
PASSIVE PROCESS: DIFFUSION,OSMOSIS,PASSIVE TRANSPORT, FACILLATED TRANSPORT
ACTIVE PROCESS: ACTIVE TRANSPORT, ENDOCYTOSIS, EXOCYTOSIS
ENDOCYTOSIS: PINOCYTOSIS,ENDOCYTOSIS
The Art Pastor's Guide to Sabbath | Steve ThomasonSteve Thomason
What is the purpose of the Sabbath Law in the Torah. It is interesting to compare how the context of the law shifts from Exodus to Deuteronomy. Who gets to rest, and why?
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
We all have good and bad thoughts from time to time and situation to situation. We are bombarded daily with spiraling thoughts(both negative and positive) creating all-consuming feel , making us difficult to manage with associated suffering. Good thoughts are like our Mob Signal (Positive thought) amidst noise(negative thought) in the atmosphere. Negative thoughts like noise outweigh positive thoughts. These thoughts often create unwanted confusion, trouble, stress and frustration in our mind as well as chaos in our physical world. Negative thoughts are also known as “distorted thinking”.
Synthetic Fiber Construction in lab .pptxPavel ( NSTU)
Synthetic fiber production is a fascinating and complex field that blends chemistry, engineering, and environmental science. By understanding these aspects, students can gain a comprehensive view of synthetic fiber production, its impact on society and the environment, and the potential for future innovations. Synthetic fibers play a crucial role in modern society, impacting various aspects of daily life, industry, and the environment. ynthetic fibers are integral to modern life, offering a range of benefits from cost-effectiveness and versatility to innovative applications and performance characteristics. While they pose environmental challenges, ongoing research and development aim to create more sustainable and eco-friendly alternatives. Understanding the importance of synthetic fibers helps in appreciating their role in the economy, industry, and daily life, while also emphasizing the need for sustainable practices and innovation.
Welcome to TechSoup New Member Orientation and Q&A (May 2024).pdfTechSoup
In this webinar you will learn how your organization can access TechSoup's wide variety of product discount and donation programs. From hardware to software, we'll give you a tour of the tools available to help your nonprofit with productivity, collaboration, financial management, donor tracking, security, and more.
The Roman Empire A Historical Colossus.pdfkaushalkr1407
The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
This is a presentation by Dada Robert in a Your Skill Boost masterclass organised by the Excellence Foundation for South Sudan (EFSS) on Saturday, the 25th and Sunday, the 26th of May 2024.
He discussed the concept of quality improvement, emphasizing its applicability to various aspects of life, including personal, project, and program improvements. He defined quality as doing the right thing at the right time in the right way to achieve the best possible results and discussed the concept of the "gap" between what we know and what we do, and how this gap represents the areas we need to improve. He explained the scientific approach to quality improvement, which involves systematic performance analysis, testing and learning, and implementing change ideas. He also highlighted the importance of client focus and a team approach to quality improvement.
1. Human Physiology Chapter 6: Movement of molecules across cell membranes John Paul L. Oliveros, MD
2. Diffusion Molecules of any substance are in a continuous state of movement or vibration The warmer the substance is, the faster its molecules move The average speed of the “thermal motion” depends on the mass of the molecule Water= 2500km/h Glucose= 850km/h In solutions, molecules cannot travel very far before colliding with other molecules The movement of molecules are random The random thermal movement of molecules will redistribute solutes in a solution from regions of higher concentration to regions of lower concentration Diffusion: movement of molecules from one location to another due to random thermal motion
5. Diffusion Flux amount of material crossing a surface in a unit of time Net Flux The difference between the 2 one-way fluxes Determines the net gain/loss of molecules from compartments separated by a membrane Always occur in the direction from higher to lower concentration Distribution Equilibrium The two one-way fluxes are equal in magnitude but opposite in direction Net flux is equal to zero No further changes in the concentration of a substance in the 2 compartments will occur
6. Diffusion Properties of diffusion: Three fluxes can be determined at any surface (2 opposite one-way fluxes; one net flux) The net flux is the most important component in diffusion since it is the net amount of material transfered from one location to the other The direction and the magnitude of the net flux are determined by the concentration difference The net flux always proceeds from regions of higher concentration to regions of lower concentration The greater the difference of concentration between any two regons the greater the magnitudeof the net flux
7. Diffusion Factors determining the magnitude of the net flux at any given concentration difference Temperature Inc. Temp inc. Speed of molecular movement inc. Net flux Mass of the molecule Inc. mass dec. Speed of mol. Mov. dec net flux Surface area Inc S.A. inc space for diffusion inc net flux Medium of which the molecules are moving Air > Water
8. Diffusion Diffusion rate vs Distance Diffusion times increase in proportion to the square of the distance over which the molecules diffuse 265 days 15ms
9. Diffusion Diffusion through membranes Magnittude of the net flux is directly proportional to the difference in concentration across the membrane, the surface area of the membrane, and the membrane permeability constant
10. Diffusion Diffusion through the lipid bilayer Major limiting factor of diffusion across membrane Polar molecules disolve into cells slowly or not at all Organic molecules Nonpolar molecules dissolve rapidly Can dissolve in the nonpolar regions of the lipid membrane Oxygen, carbon dioxide, fatty acids, steroid hormones
11. Diffusion Diffusion of Ions through Protein Channels Ions (Na+, K+, Cl -, Ca++) diffuse faster in cells with more integral membrane proteins Integral proteins form channels Selectivity on passage of ions Diameter Polarity of surface
12. Diffusion Role of Electric Forces on Ion Movement Membrane potential Separation of charges across the cell membrane electric force that influences movemnt of ions across membranes Same sign elcetric charges repel each other Different sign charges attract each other Most cellss are electrically negative atract + charged ion Electrochemical gradient Electrochemical difference across a membrane Concentration difference + electrical difference (membrane potential
13. Diffusion Regulation of Diffusion through ion channels Channel gating Process of opening and closing ion channels Patch clamping Technique that helped study ion channels Ligand sensitive channels Binding of specific molecules to channel proteins produces allosteric or covalent changes of the protein Voltage-gated channels Changes in the membrane potential causes movement of charged regions of the channel proteins Mechanosensitive channels Stretching the membrane affect the conformation of some channel proteins
14. Mediated Transport Systems Transporters/carriers Integral membrane proteins that mediate the passage of large or polar molecules and non-diffusional movement of ions Factors determining magnitude of solute flux Extent to which transporter binding sites are saturated The number of transporters in a membrane Rate of conformational change in the transport protein
15. Mediated Transport Systems When transporters are reportedly almost saturated, the maximal transport flux depends on the rate of conformational change of the transporter to transfer its protein from one surface to the other
16. Mediated Transport System Facilitated Diffusion Uses a transporter to move solutes downhill, from a higher to lower concentration until concentration between the 2 sides are the same Really doesn’t involve diffusion but end results are the same No energy is involved E.g. Glucose transport
17. Mediated Transport Systems Active Transport Uses energy to move a substance against its electrochemical gradient (uphill) Requires binding of the substance to the transporter in the membrane AKA pumps Also exhibits specificity and saturation Active transport Needs continuous input of energy Alter the affinity of the binding site on the transporter; higher affinity when facing one side of the membrane than the other Alter the rates at which the binding site on the transporter is shifted from one surface to the other Two types: Primary active transport Secondary active transport
18. Mediated Transport System Primary active transport Transporter: ATPase ATP breakdown and phosphorylation of ATPaseenergy Events during active transport Exposure of binding site to ECF Binding of solute to the binding site Removal of the PO4 group of the transporter Release of solute to ICF Rephosphorylation of binding site as it agian exposed to ECF
19. Mediated Transport Systems Primary Active Transport Na, K-ATPase Present in all plasma membranes High intracellular K+ and low intracelluilar Na+ 1 ATP 3 Na+, out , 2K+ in Ca-ATPase In plasma membrane and endoplastic reticulum H-ATPase In PM, mitochondria and lysosomes H, K-ATPase In acid secreting cells of stomach and kidneys
20. Mediated Transport System Secondary Active Transport Use ion concentration gradient as energy source Events during secondary active transport Altering the affinity of the binding site for the solute Altering the rate of at which the binding site is shifted from one surface to the other Protein allosteric modulation due to ion binding
21. Mediated Transport System Secondary Active Transport Cotransport Solute moves with same direction as ion Countertransport Solute move opposite direction of ion
22. Mediated Transport System Secondary active transport Na+, Ca++ countertransport Digitalis Inhibits Na+,K+-atpase in heart muscle cells Increase in IC Na+ Increase in IC Ca++ Increase in force of contraction of heart muscles
26. Osmosis Water Small polar molecule 0.3 nm in diameter Plasma membranes 10x more permeable to water than artificial membranes Aquaporins: Membrane proteins that form channels where water can diffuse Number differs in different membranesa Can be alterted in response to various signals Osmosis Net diffusion of water across membranes Additon of solute decreases concentration concentration difference flux Mol Wt of H20 = 18 1L H20 =1kg Conc. Of H20 in pure H20 = 1000/18 = 55.5M 1 molecule of solute will displace1 molecule of H20 Dec in H20 conc= conc of solute 1M of glucose = 54.5 M H20
27. Osmosis The degree to which H20 conc is decreased by addition of a solute depends upon the number of particles (molecules/ions) of solute in a solution and not upon the chemical nature of the solute e. g. Concentration of 1 mol glucose solution = 1mol AA soultion= 1 mol urea solution A molecule that ionizes in a solution decreases the water concentration in proportion to the number of ions formed e.g. 1 M of MgCl++ lowers water conc 3x than 1 M glucose
28. Osmosis Osmolarity Total solute concentration of a solution 1 osm = 1 molecule of particle in a solution 1M of glucose = 1osm I M of NaCl = 2 osm The higher the osmolarity, the lower the water concentration
29. Osmosis Membrane impermeable to solutes but permeable to water Just like plasma membrane Equilibrium: Equal concentrations in both compartments Volume in expands in the compartment with more solutes if compartments are infinitely expandle, net transfer doesn’t create a pressure gradient
30. Osmosis Membrane impermeable to solutes but permeable to water but non-expandable/limited expansion H20 moves to compartment with more solutes increase in pressure of compartment oppose net water entry Osmotic pressure: the pressure that must be applied to the solution to prevent the net flow of H2O into the solution
31. Osmosis Extracellular osmolarity and cell volume 85% of EC solutes are Na++ and Cl- Na++ moved out by Na, K-ATPase pump Cl- moved out by secondary active-transport pumps Both ions behave as non-penetrating solutes Intracellular K+ and organic molecules Organic molecules are large and polar, thus are non-penetrating K+ is moved preferably moved into cells by Na, K-ATPase pump Both intracellular extracellular osmolarity are kept at 300 mOsm
33. Endocytosis and Exocytosis Endocytosis: Folding of regions of PM small pockets IC vesicles Exocytosis: IC vesicles fusion with PM release of contents EC
34. Endocytosis Pinocytosis (cell drinking) Fluid endocytosis Enclosure of a small volume of ECF Adsorptive endocytosis Molecules bind to membrane CHONs and are carried along with ECF inside the cell when membrane invaginates Phagocytosis (cell eating) Large particles are engulfed by cells PM folds around the surface of the particle so that little ECF is enclosed within the vesicles
35. Exocytosis Funtions: To replace portions of PM removed during endocytosis Route for impermeable CHONs getting outside cell New CHONs endoplasmic reticulum processing in golgi apparatus vesicles plasma membrane released to ECF Release triggered by stimuli that leads to an increase in cytostolic concentration in cells Stimuli opens Ca++ channels in PM and/or membranes of IC organelles Increase in Ca++ activates CHONs requiredfor the vesicle membrane to fuse with the PM and secrete contents EC For rapid secretion of materials in response to stimulus
36. Epithelial Transport Epithelial cells Line hollow organs and tubes Regulate absorption and secretion of substances across membranes Luminal/Apical membrane Surface facing a hollow or fluid filled chamber Basolateral membrane: Adjacent to network of blood vessels Opposite apical membrane 2 pathways crossing the epithelium Paracellular pathway Diffusion between adjacent cells Limited due o tight junction membranes Transcellular pathway Movement across cell from apical to basal membrane
37. Epithelial Transport Transcellular Transport Through diffussion and mediated transport Different transport and permeability characteristics between apical and basement membranes Substances undergo active transfusion across the overall epithelial layer e.g. GI tract, kidneys, glands
39. Glands Glands Secrete specific substances into the extracellular fluid or the lumen of ducts in response to appropriate stimuli Formed during embryonic development by the infolding of the epithelial layer of an organ’s surface Types of Glands Exocrine gland Secretions flow through the ducts and are discharged into the lumen of an organ or the surface of the skin e.g. Sweat glands, salivary glands Endocrine gland Ductless glandsbr />Secretions are released directly on the interstitial fluid surrounding the gland cells Secretions then diffuses into the blood carrying it to all of the body
40. Glands Endocrine glands Hormones Major class of chemical messengers Non-hormonal organic substances e.g. Liver: glucose, A.A., fats, CHONs, Types of glandular secretions Organic material Synthesized by cells Salts and water From blood supplying the tissue
41. Glands Glands Undergo low basal rate of secretion Signal (nerve signals, hormones) augnmentation of secretions Mechanisms in increasing secretion: 1. increase rate of synthesis by increasing enzyme 2. providing Ca ++ for exocytosis 3. altering pumping rates of transporter or opening ion channels Glands Volume of secretion increased by increasing Na+ pump activity or controlling the opening of Na+ channels in the PM Increase in Na+ in the epithelium increases flow of H20 by osmosis