Cell Membrane The Door to the Cell. Structure of the Cell Membrane.
Crossing the Cell Membrane
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Transcript of Crossing the Cell Membrane
Crossing the Cell Membrane
OsmosisActive Transport
Passive transport DiffusionEndo/Exo - Cytosis
Warm Up Questions:1. All _______________ are composed of cells.
2. New cells are produced from _________________.
3. What is the main purpose of the cell membrane?
4. What are some examples of manmade membranes? (Try to think of at least two.)
Cell MembranesMade up of a lipid bi-layer
Selectively Permeable: Not all particles can pass through the membrane without help from special membrane proteins
Active TransportThe process by which proteins on the cell
membrane push particles from one side of the membrane to the otherRequires energy (ATP)
Occurs when particles are two large to diffuse through a membrane or;
Occurs when particles are moving against the forces of diffusion (Particles are moving from an area of low concentration to an area of high concentration)
Active Transport
H2O
H2O
H2O
H2O
H2O
H2O
H2O
H2O
H2O
H2O
H2O
A B
Na+
Na+
Na+
Na+
Active Transport
Active Transport
Passive TransportNormal Diffusion that requires membrane proteins
Channel ProteinsCarrier Proteins
EndocytosisEndocytosis is the process by which nutrients are
engulfed by the cell membrane
ExocytosisThe process by which a vesicle inside the cell
fuses with the cell membrane and expels its contents outside the cell