BIOL1007 Lecture Notes - Lecture 13: Lipid Bilayer, Cell Membrane, Semipermeable Membrane
Explain the major functions of the plasma membrane
Separates contents of cell from outside environment
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Protects inside of cell, only Allows certain molecules to pass in and out of cell, regulation
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Serves as base of attachment for the cytoskeleton in some organisms and cell wall in others,
supports cell and helps maintain shape
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Lipids - give flexibility
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Proteins - monitor and maintain cell's chemical climate, assist molecule transfer across
membrane
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Primarily composed of proteins and lipids
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phospholipid bilayer semi-permeable, allows only selected molecules to diffuse across it
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Describe passive (diffusion and osmosis) and active processes which
allow the flow of substances across a semi permeable cell membrane
Passive processes
Passive diffusion
No energy input
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Screen clipping taken: 4/11/2017 10:31 PM
Osmosis
Water moves from area of high to low conc
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L13 - compartmentalisation of cells
Saturday, 30 September 2017
12:28 AM
Mod 2 Energy Systems and Cells Page 1
Screen clipping taken: 4/11/2017 10:33 PM
Active processes
Controlled channels
Opens up when wants things to come in e.g. nerve cells
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Use powered transport
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Use ATP to carry molecule to other side of membrane
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Screen clipping taken: 4/11/2017 10:32 PM
phagocytosis
Consumes bacterial cells
Screen clipping taken: 4/11/2017 10:36 PM
pinocytosis
Brings in solute molecules
Screen clipping taken: 4/11/2017 10:36 PM
Import into cell
Mod 2 Energy Systems and Cells Page 2
Document Summary
Explain the major functions of the plasma membrane. Protects inside of cell, only allows certain molecules to pass in and out of cell, regulation. Serves as base of attachment for the cytoskeleton in some organisms and cell wall in others, supports cell and helps maintain shape. Proteins - monitor and maintain cell"s chemical climate, assist molecule transfer across membrane phospholipid bilayer semi-permeable, allows only selected molecules to diffuse across it. Describe passive (diffusion and osmosis) and active processes which allow the flow of substances across a semi permeable cell membrane. Water moves from area of high to low conc. Mod 2 energy systems and cells page 1. Opens up when wants things to come in e. g. nerve cells. Use atp to carry molecule to other side of membrane. Mod 2 energy systems and cells page 2 endocytosis protein pulled into cell. Exergonic - energy released, endergonic - energy put in.