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
Premium Protein Cell membrane Lipid bilayer
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
Premium Protein Cell membrane Membrane biology
unit of the nervous system. These neurons work together with other excitable cells to produce action potentials when they receive electrical or chemical stimuli. Action potentials can be thought of as an “all-or-nothing” event and occur as a large-scale depolarization when sodium and other positive ions rapidly enter the neuron through membrane channel proteins. Once initiated‚ action potentials travel down the length of the axon and when it reaches the end a neurotransmitter is released into the
Premium Neuron Action potential Axon
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
Premium Bacteria Cell Cell membrane
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
Premium Lipid bilayer Cell membrane Cell
Part 1 Part 1 of the experiment investigated the effect of different temperatures on beetroot cell membranes (a type of plant cell). Through this experiment‚ the process of diffusion and osmosis was in action. Various temperatures ranging from low temperatures to high temperatures such as -5⁰C‚ 5⁰C‚ 30⁰C‚ 50⁰C and 80⁰C were used to investigate the temperature effects on beetroot cell membranes. The hypothesis predicted that the higher the temperature the darker the beetroot substance and the lower
Premium Cell membrane Cell PH
the cell membrane with the correct terms integral proteins‚ channel proteins and bilipid construction. Your last paragraph was very detailed with great information about the cell membrane‚ you stated “ The cell membrane is very thin and fragile‚ and it contains two different types of proteins. “Integral proteins are part of the membrane structure and cannot be removed without damaging or destroying the membrane. Peripheral proteins are bound to the inner or outer surface of the membrane and are easily
Premium Cell membrane Gene Cell
Experiment 5 Title: Membrane Permeability Objectives: 1. Define solvent‚ solute‚ solution‚ selectively permeable‚ diffusion‚ osmosis‚ concentration gradient‚ equilibrium‚ turgid‚ plasmolyzed‚ plasmolysis‚ turgor pressure‚ tonicity‚ hypertonic‚ isotonic‚ hypotonic; 2. Describe the effects of hypertonic‚ isotonic‚ and hypotonic solutions on Elodea leaf cells and onion scale leafs. Introduction: Membrane permeability is a quality of a cell’s plasma membrane that allows substances to pass in
Premium Osmosis Cell Cell wall
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
Premium Cell membrane Protein
Title Membrane Permeability Aim To determine the effect of various chemicals and high temperature on the membrane permeability of beetroot Hypothesis Organic solvent and high temperature will destroy the cell membrane and make it permeable to the red pigment. The higher the concentration of the alcohol‚ the greater will be this effect. Principle Beetroot is the material used in this experiment to demonstrate the effects of high temperature and chemicals on the permeability of the cell membranes
Premium Protein Cell membrane Ethanol