Cell membrane and membrane transport

Covers and protects the cells cytoplasm and controls what goes in/out and connects cells to each other

• phosphilipds • proteins • cholestrol • glycoproteins (carb & protein) • Glycolipids ( cab & lipid)

channel carriers selectively move Ions through the membrane in/out.

via selectively permeable membrane

freely pass through and gasses and fat soluble substances can slip through

allow water and ions to pass through a channel

substances moving across cell membrane due to kinectic energy. and do bulk transport NO ATP

involves substances moving across membrane with the use of energy, they go across their concentration gradient.

• the movement of molecules from area of their own high concentration to an area of their own low concentration • with or with out membrane • they include steroids fat soluble vitamins (D, E, K,A) O2 & CO2 etc

• movement of water through selective permeable membrane from an area of high water concentration (hypotonic) to an area of low water Concentration (Hypertonic) • “where NA+ goes H2O follows”

low concentration of solutes

higher concentration of solute.

• The movements of molecules across the membrane down their concentration gradient

have a concentration of amino acids and they push glucose through their protein carrier

• let ions or water through and have gates to let them through (H2O, NA+, K)

• is done by protein structures in the cell membrane called a ‘Pump’. • uses ATP to push substances across the cell membrane against high concentrated substances

• a vesicle is a small membrane-bound spherical sac and is formed by budding off of the membrane

• vesicles fuse with plasma membrane releasing their contents out of the cell into extracellular fluid e.g. proteins synthesised in the cell packaged to leave the cell.

• materials move into the cell • Pagnocytosis (particles) • Pinocytosis ( fluid)

contains digestive enzymes