Biological Membranes Lipid Membranes • Receptors‚ detecting the signals from outside: Light Odorant Taste Chemicals A Hormones Neurotransmitters Drugs • Channels‚ gates and pumps • Electric/chemical potential Neurophysiology Energy • Energy transduction: Photosynthesis Oxidative phosphorylation • • • • • • Structure Function Composition Physicochemical properties Self-assembly Molecular models highly selective permeability barrier Internal membranes for organelles Bilayer Permeability
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Experiment 2 : Transport Across Membrane Name : Matrix No : Group : B Semester : 1 Date of Experiment : 05.09.2013 Lecturer’s Name : Miss OBJECTIVE To study the effects of hypotonic‚ hypertonic and isotonic solutions on plant and animal cells. INTRODUCTION In cellular biology the term membrane transport refers to the collection of mechanisms that regulate the passage of solutes such as ions and small molecules through biological membranes‚ which are lipid bilayers
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BIOSC 048: Problem Set Questions 1. Given that cell A has significantly more nongated K+ channels than cell B‚ which cell has the larger resting membrane potential? Explain. If the permeability to K is higher in A than in B‚ then the resting membrane potential (rmp) will be closer to the equilibrium potential in cell A‚ which means the rmp will be more negative in cell A than in cell B; or in other words‚ the potential difference will be LARGER in cell A. 2. Predict the effect of a reduced
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Cell Membranes and Transport Hands-On Labs‚ Inc. Version 42-0033-00-01 Exercise 1: Diffusion Observations Data Table 1: Rate of diffusion in different temperatures | | ºC | Minutes | Temperature | InitialTemp. | InitialColor | 5 | 10 | 15 | 20 | 25 | 30 | 60 | Cold | 10°celsius | clear | clear | clear | clear | clear | clear | light purple | light purple | Ambient | 25°celsius
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1 The Effect of Molecular Weight on the Rate of Diffusion of Substances1 Alexander Ken Libranza Group 1 Sec. A – 1L March 6‚ 2012 A scientific paper submitted in partial fulfillment of the requirements in General Biology I laboratory under Prof. Cheryl M. Talde‚ 2nd sem.‚ 2011-2012. 1 2 ABSTRACT The effect of molecular weight on the rate of diffusion was assessed using two tests: the glass tube test and the agar-water gel test. In the glass tube set-up‚ two cotton plugs soaked
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on plant cell membranes The purpose of this activity is: • to practise experimental and investigative skills • to investigate the effect of temperature on cell membrane structures Procedure SAFETY: Always carry scalpels clasped to a tile and with the tip pointing away from you. Beetroot cells contain pigments called betalains that give the tissue its dark purple-red colour. The pigment is contained in the cell vacuole. Investigation a. Collect 3 or 4 beetroot cores from the
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called peptidoglycans. Just inside the cell wall is a less rigid envelope called the plasma membrane also known as the cytoplasmic membrane. In bacterial cells the plasma membrane has two primary functions: it serves as a selective barrier to molecules that are penetrating the cell wall allowing water and oxygen to flow easily into the cell but restricting other proteins from entering; secondly‚ the plasma membrane contains enzymes proteins that cause chemical reactions to occur that are vital to the
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4.1 Aim The aim of this lab session is to demonstrate the effect of different conditions on membrane permeability. 4.2 Learning Objectives In this Lab Session‚ students will acquire the skills to: - analyze the effect of different temperatures on membrane integrity. - analyze the effect of the organic solvent acetone on membrane integrity. 4.3 Introduction Even though membranes separate cells from their surrounding environment and different organelles within the cells from the
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Cell Membrane Permeability and Osmosis Experiment 3 Objectives: To demonstrate the mechanism involved in Osmosis; To demonstrate the tonicity of solutions by subjecting the cells to different concentration of solute. To view‚ under the microscope‚ any change in the shape and volume of the cells after subjecting them to different concentrations of solutes; To demonstrate the permeability of cell membrane by subjecting the cells to different solutes; To demonstrate the mechanism involved in
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2. Draw and completely label a cell membrane. [pic] 4. List and briefly discuss the 5 components of cellular membranes. 1. Phospholipids layer- 2 layers ‚ polar and non polar ‚ polar facing the extracellular fluid and cytoplasm 2. Transmembrane proteins-integral membrane proteins are proteins that expand the membrane 3. Interior protein network-peripheral proteins are in the interior side of the membrane 4. Cell surface markers are glycolipids‚ carbohydrates/lipid
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