* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Cell Transport
Survey
Document related concepts
Model lipid bilayer wikipedia , lookup
Cell nucleus wikipedia , lookup
Lipid bilayer wikipedia , lookup
Cellular differentiation wikipedia , lookup
Extracellular matrix wikipedia , lookup
Cell culture wikipedia , lookup
Cell encapsulation wikipedia , lookup
Cell growth wikipedia , lookup
Membrane potential wikipedia , lookup
Signal transduction wikipedia , lookup
Cytokinesis wikipedia , lookup
Organ-on-a-chip wikipedia , lookup
Cell membrane wikipedia , lookup
Transcript
CELL TRANSPORT Roselyn Aperocho – Naranjo Pharmacy Instructor USPF – College of Pharmacy www.roselynnaranjo.vze.com The Cell Membrane Anatomy Composition Function Cell Coat Chondroitin Principal sufuric Acid Hyaluronic Acid Collagen, Elastin Sialic Acid component of connective tissue Adsorption of compounds Cell Membrane Protein Hydrophilic Triglycerides Lipophilic Steroids Layer,bimolecular (barrier) Phospholipids (lecithin) Thickness Layer 20-25 Å THE CELL MEMBRANE CELL COAT Cell Coat Protein 25 Å Membrane Phospholipids 25 Å Protein 25 Å Inside of the Cell Schematic Diagram of the Cell membrane Structure having a pore THE CELL MEMBRANE Properties of the Membranes Permeability - Lipid soluble unionized substances dissolved in the lipid membrane during transfer (Factors involved: pka, pH, lipid/water partition coefficient)- - passive diffusion - - - ion pair - water soluble, lipid insoluble substance of small molecular weight transfer through water-filled pores in the membrane- - - - convective transport - solid substances and oil droplets may transfer the membrane in a vessel - - - - pinocytosis Properties of the Membranes Surface Tension – very low due to adsorption of protein to the outside of the lipid layer Electrical Properties – membrane potential due to different distribution of ions in the extracellular and intracellular fluid THE CELL MEMBRANE LIPID BILAYER Basic structural framework Consist of two back to back layers made up of three types of lipid molecules – (75%) Phospholipids, cholesterol, glycolipids 2 layers of phospholipids • Phosphate head is polar (water loving) • Fatty acid tails nonpolar (water fearing) • Proteins embedded in membrane THE CELL MEMBRANE Functions Controls what enters and exits the cell to maintain an internal balance called homeostasis b. Provides protection and support for the cell have pores (holes) in it c. Selectively permeable: Allows some molecules in and keeps other molecules out d. The structure helps it be selective! a. THE CELL MEMBRANE Types of Cellular Transport Passive Transport cell doesn’t use energy 1. 2. 3. Diffusion Facilitated Diffusion Osmosis Weeee!!! high low Active Transport cell does use energy 1. 2. 3. Protein Pumps Endocytosis Exocytosis This is gonna be hard work!! high low THE CELL MEMBRANE Passive Transport (HighLow) cell uses no energy molecules move randomly Molecules spread out from an area of high concentration to an area of low concentration. Four types: 1. Diffusion 2. Facilitative Diffusion – diffusion with the help of transport proteins 3. Osmosis – diffusion of water THE CELL MEMBRANE Passive Transport (HighLow) 1. Diffusion: random movement of particles from an area of high concentration to an area of low concentration. (High to Low) • Diffusion continues until all molecules are evenly spaced (equilibrium is reached)-Note: molecules will still move around but stay spread out. THE CELL MEMBRANE Passive Transport (HighLow) 2. Facilitated diffusion: diffusion of specific particles through transport proteins found in the membrane a. Transport Proteins are specific – they “select” only certain molecules to cross the membrane b. Transports larger or charged molecules Facilitated diffusion (Channel Protein) Diffusion (Lipid Bilayer) Carrier Protein THE CELL MEMBRANE Passive Transport (HighLow) Glucose molecules 2. Facilitated diffusion: High Concentration High Cell Membrane Low Concentration Through a Transport Protein Low THE CELL MEMBRANE Passive Transport (HighLow) 3.Osmosis: diffusion of water through a selectively permeable membrane Water moves from high to low concentrations •Water moves freely through pores. •Solute (green) to large to move across. THE CELL MEMBRANE Active Transport (Low High) cell uses energy actively moves molecules to where they are needed Movement from an area of low concentration to an area of high concentration (Low High) Three Types: – – – Protein pumps Endocytosis Exocytosis THE CELL MEMBRANE Active Transport (Low High) 1. Protein Pumps transport proteins that require energy to do work – Example: Sodium / Potassium Pumps are important in nerve responses. Protein changes shape to move molecules: this requires energy! THE CELL MEMBRANE Active Transport (Low High) 2. Endocytosis: taking bulky material into a cell • • • • • Uses energy Cell membrane in-folds around food particle “cell eating” forms food vacuole & digests food This is how white blood cells eat bacteria! THE CELL MEMBRANE Active Transport (Low High) 3. Exocytosis: Forces material out of cell in bulk • membrane surrounding the material fuses with cell membrane • Cell changes shape – requires energy EX: Hormones or wastes released from cell • ELECTROLYTES What are electrolytes? Chemically, electrolytes are substances that become ions in solution and acquire the capacity to conduct electricity. Electrolytes are present in the human body, and the balance of the electrolytes in our bodies is essential for normal function of our cells and our organs. Common electrolytes that are measured by doctors with blood testing include sodium, potassium, chloride, and bicarbonate. The functions and normal range values for these electrolytes are described on the next slide. ELECTROLYTES NATRIUM/ SODIUM Sodium is the major positive ion (cation) in fluid outside of cells. The chemical notation for sodium is Na+. When combined with chloride, the resulting substance is table salt. Excess sodium (such as that obtained from dietary sources) is excreted in the urine. It regulates the total amount of water in the body and the transmission of sodium into and out of individual cells also plays a role in critical body functions. Many processes in the body, especially in the brain, nervous system, and muscles, require electrical signals for communication. The movement of sodium is critical in generation of these electrical signals. Too much or too little sodium therefore can cause cells to malfunction, and extremes in the blood sodium levels (too much or too little) can be fatal. ELECTROLYTES NATRIUM/ SODIUM Increased sodium (hypernatremia) in the blood occurs whenever there is excess sodium in relation to water. There are numerous causes of hypernatremia; these may include kidney disease, too little water intake, and loss of water due to diarrhea and/or vomiting. A decreased concentration of sodium (hyponatremia) occurs whenever there is a relative increase in the amount of body water relative to sodium. This happens with some diseases of the liver and kidney, in patients with congestive heart failure, in burn victims, and in numerous other conditions. A Normal blood sodium level is 135 - 145 milliEquivalents/liter (mEq/L), or in international units, 135 - 145 millimoles/liter (mmol/L). ELECTROLYTES POTASSIUM Potassium is the major positive ion (cation) found inside of cells. The chemical notation for potassium is K+. The proper level of potassium is essential for normal cell function. Among the many functions of potassium in the body are regulation of the heartbeat and the function of the muscles. A seriously abnormal increase in potassium (hyperkalemia) or decrease in potassium (hypokalemia) can profoundly affect the nervous system and increases the chance of irregular heartbeats (arrhythmias), which, when extreme, can be fatal. ELECTROLYTES POTASSIUM Increased potassium is known as hyperkalemia. Potassium is normally excreted by the kidneys, so disorders that decrease the function of the kidneys can result in hyperkalemia. Certain medications may also predispose an individual to hyperkalemia. Hypokalemia, or decreased potassium, can arise due to kidney diseases; excessive loss due to heavy sweating, vomiting, or diarrhea, eating disorders, certain medications, or other causes. The normal blood potassium level is 3.5 - 5.0 milliEquivalents/liter (mEq/L), or in international units, 3.5 - 5.0 millimoles/liter (mmol/L). ELECTROLYTES CHLORIDE Chloride is the major anion (negatively charged ion) found in the fluid outside of cells and in the blood. An anion is the negatively charged part of certain substances such as table salt (sodium chloride or NaCl) when dissolved in liquid. Sea water has almost the same concentration of chloride ion as human body fluids. Chloride also plays a role in helping the body maintain a normal balance of fluids. ELECTROLYTES CHLORIDE The balance of chloride ion (Cl-) is closely regulated by the body. Significant increases or decreases in chloride can have deleterious or even fatal consequences: Increased chloride (hyperchloremia): Elevations in chloride may be seen in diarrhea, certain kidney diseases, and sometimes in overactivity of the parathyroid glands. Decreased chloride (hypochloremia): Chloride is normally lost in the urine, sweat, and stomach secretions. Excessive loss can occur from heavy sweating, vomiting, and adrenal gland and kidney disease. The normal serum range for chloride is 98 - 108 mmol/L. ELECTROLYTES BICARBONATE The bicarbonate ion acts as a buffer to maintain the normal levels of acidity (pH) in blood and other fluids in the body. Bicarbonate levels are measured to monitor the acidity of the blood and body fluids. The acidity is affected by foods or medications that we ingest and the function of the kidneys and lungs. The chemical notation for bicarbonate on most lab reports is HCO3- or represented as the concentration of carbon dioxide (CO2). The normal serum range for bicarbonate is 22-30 mmol/L. ELECTROLYTES BICARBONATE The bicarbonate test is usually performed along with tests for other blood electrolytes. Disruptions in the normal bicarbonate level may be due to diseases that interfere with respiratory function, kidney diseases, metabolic conditions, or other causes. ELECTROLYTES Normal Value Calcium 8.8 - 10.3 mg/dL Potassium 3.5 - 5.0 mEq/L Calcium, ionized 2.24 - 2.46 meq/L Sodium 135 - 145 mEq/L Chloride 98 - 108 mEq/L Ferritin Magnesium 1.6 - 2.4 mEq/L Folate Phosphate 2.5 - 4.5 mg/dL Glucose, fasting 13 - 300 (ng/ml) 3.6 - 20(ng/dl) 60 - 110(mg/dl) Glucose (2 hours postprandial) (mg/dl) Up to 140 Hemoglobin A1c 6-8 Iron (mcg/dl) 65 - 150 Lactic acid (meq/L) 0.7 - 2.1 LDH (lactic dehydrogenase) 56 - 194 IU/L THE CELL MEMBRANE Hypotonic Solution Hypotonic: The solution has a lower concentration of solutes and a higher concentration of water than inside the cell. (Low solute; High water) Result: Water moves from the solution to inside the cell): Cell Swells and bursts open (cytolysis)! THE CELL MEMBRANE Hypertonic Solution Hypertonic: The solution has a higher concentration of solutes and a lower concentration of water than inside the cell. (High solute; Low water) shrinks Result: Water moves from inside the cell into the solution: Cell shrinks (Plasmolysis)! THE CELL MEMBRANE Isotonic Solution Isotonic: The concentration of solutes in the solution is equal to the concentration of solutes inside the cell. Result: Water moves equally in both directions and the cell remains same size! (Dynamic Equilibrium) THE CELL MEMBRANE What type of solution are these cells in? A B Hypertonic C Isotonic Hypotonic Prepare one – half sheet of paper Good Luck to be continued…