Zusammenfassung der Ressource
Transport across membranes
- Cell Membrane
- Made of phospholipid
bi-layer and other
proteins
- The bi-layer allos lipid soluble molecules to pass through
by simple diffusion but prevents the passage of small
polar ions
- selectively permeable membrane
- Fluid-mosaic model
- The lipid bi-layer gives fluidity and elasticity to the cell
membrane.
- Cholesterol in the cell membrane
- Decreases permeability and increases
stability of the membrane
- Different type of cells have different amounts of
cholesterol
- Carrier proteins
- Aid the transport of ions/polar molecules
and large molecules (facilitated diffusion
and active transport)
- Enzymes can also be
found embedded on
the membrane
- Glycoprotiens
- Composed of carbohydrate and protiens, are on
the outer surface of the membrane are
important in cell recoginition and sometimes act
as antigens
- Aquaporins
- Aids the movement of water across the
membrane