Topic 2 – Cell membranes Reading Chapter 5 Objectives Functions of cell membranes The fluid mosaic model The lipid bilayer – phospholipids‚ glycolipids and sterols Properties of the lipid bilayer Membrane proteins – the ‘mosaic’ in the model Solute movements across membranes BIO 1140 – SLIDE 1 http://www.nikonsmallworld.com/gallery/year/2006/id/751 Functions of cell membranes – an overview Fluid mosaic model Singer & Nicolson 1972 Fluid lipid molecules in which
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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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temperature had on the permeability of the cell membrane. Introduction Located within the vacuole of beetroot cells is a red pigment call Betalains. Typically these pigments are contained within the cell vacuole by the tonoplast (vacuole membrane)‚ however When beetroot is heated these red pigments escape the vacuole. This experiment aims to explore the effect of temperature on the permeability of the cell membranes (i.e. Tonoplast). ‘The cell surface membrane is the plasma membrane that surrounds
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fluid mosaic model of the cell membrane. What is the fluid mosaic model? The fluid mosaic model is a model conceived by S.J. Singer and Garth Nicolson in 1972 to describe the structural features of biological membranes. The membrane is described to be fluid because of its hydrophobic integral components such as lipids and membrane proteins that move laterally or sideways throughout the membrane. That means the membrane is not solid‚ but more like a ’fluid’. The membrane is depicted as mosaic because
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The Cell membrane surrounds all living cells and is the most important organelle‚ there is also a similar plasma membrane that surrounds all the organelles except for the ribosome. The membrane controls how and what substances can move in and out of the cell/organelle The structure of the membrane is often referred to as the “Fluid Mosaic Model”; this is because of the way it is structured It is composed of phospholipids‚ proteins‚ and carbohydrates‚ which are arranged in a fluid
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Assignment 1: Cell Membranes and Temperature Background Theory Beetroot contains betalain pigments within it’s vacuole‚ which gives it it’s purple-red colour‚ it’s this pigment which leaks out as the beetroot is heated and the cells membrane begins to break down. The practicals aim is to show the effect of temperature on the cell membrane by observing the colour change of the water the beetroot was placed in. The cell membrane is important as it controls the substances enters and leaves the cell with
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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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Biology Lab Report - Movement in and out of cells (4A) Shiang Chen Ting (24) Sec 313 Introduction The aim of this experiment is to explore the factors which affect the movement of materials in and out of the cells. The dark red or purple colour of Beetroots is caused by a pigment called betalain that is found within the vacuole of the beetroot cells. The pigment remains intact within the cell if the cells are not “stressed” by the external environment. In this exploration‚ two factors that affect
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The Cell: Transport Mechanisms and Cell Permeability 1. Molecular motion: A and D 2. Velocity of molecular movement: B and C 4. Size of pores. Solubility in the lipid portion of the membrane and/or presence of membrane “carriers” for the substance(s). 5. Glucose- (a) move into the sac Albumin- (c) no movement Water- (b) move out of the cell NaCl- (a) move into the celll 7. Hypertonic- C- crenated Isotonic- B Hypotonic- A- hemolysis‚ bursting open due to swelling
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century‚ little was known about cell membranes. Until the early 1950s‚ the biological cell membrane was rarely mentioned in scientific literature. It was recognised that something was probably there‚ but hardly anything about it was known. Considering the lack of technical equipment available a century ago‚ scientists such as Charles Overton and Edwin Gorter were not only exploring new territory in looking at the properties of cell membranes‚ but laying the way for future cell biologists. Scientists had
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