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?

Diffusion Movement of molecules from a place of higher concentration to a place of lower concentration 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 Glucose molecules High Concentration Protein channel Cell Membrane bilayer Low Concentration

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Active Transport Energy is required. Need ATP- the 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. Endocytosis Into Exocytosis Out of

ENDOCYTOSIS

62 Inside of the cell Outside of the cell Exocytosis

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