The Cell Membrane Selectively permeable semipermeable allows only
The Cell Membrane • Selectively permeable (semi-permeable) allows only certain substances to pass through cannot control the movement of water Cell membrane
The fluid mosaic model • double layer of lipids with proteins scattered throughout • flexible, phospholipids move with in the membrane
Main Structures of the Cell Membrane
Parts of the Cell Membrane • Transport Proteins- allows needed substances or waste materials through membrane
Parts of the Cell Membrane • Cholesterol • stabilizes the phospholipids • does not allow fatty acid chains to stick together cholesterol
How do molecules get into and out of a cell?
• Movement of molecules from a place of higher concentration to a place of lower concentration Diffusion • Always higher to lower! • No energy input required!
Osmosis: Diffusion of water through a cell membrane
Transport through the membrane Two types • Facilitated Diffusion • Energy input NOT required • Active Transport • Energy input required
Facilitated Diffusion Energy is NOT required to move substances across the membrane. Protein
Facilitated Diffusion High Concentration Cell Membrane bilayer Low Concentration Glucose molecules Protein channel
Active Transport • Energy is required. • Need ATPthe universal energy molecule. • Low to high
Other ways to get molecules into and out of a cell Some molecules are too large to get through the membrane. 1. Endocytosis • Into 1. Exocytosis • Out of
E N D O C Y T O S I S
62 Inside of the cell Exocytosis Outside of the cell
3 types of Solutions
– The solution with the higher concentration of solutes is hypertonic. – The solution with the lower concentration of solutes is hypotonic. – These are comparative terms. • Tap water is hypertonic compared to distilled water but hypotonic when compared to sea water. – Solutions with equal solute concentrations are isotonic.
What types of solution? Hypertonic Or Hypotonic
Plasmolysis
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