Fluid Mosaic Model
Cell Membrane- cell boundary, transport, communication.
Fluid Portion- moveable, phospholipid bi-layer.
Protein Mosaic- embedded proteins (integral, peripheral)
Protein Functions- Communication, recognition (cell-cell), receptor (cell-environment (hormone)), Transport channels, carrier, ATP in/out
The cell membrane is selectively permeable so that only small, non-polar molecules can easily get through phosphate bi-layer.
Fluid Portion- moveable, phospholipid bi-layer.
Protein Mosaic- embedded proteins (integral, peripheral)
Protein Functions- Communication, recognition (cell-cell), receptor (cell-environment (hormone)), Transport channels, carrier, ATP in/out
The cell membrane is selectively permeable so that only small, non-polar molecules can easily get through phosphate bi-layer.
Solutions- Made up of two parts 1. Solvent, does the dissolving. 2. Solute, being dissolved.
Dilute- less solute
Concentrated- more solute
(Less Solute = More Solvent)
Dilute- less solute
Concentrated- more solute
(Less Solute = More Solvent)
Transport
Passive
No energy required, with concentration gradient.
Rate of diffusion across cell can be affected by temperature, concentration, SA greater : volume
No energy required, with concentration gradient.
Rate of diffusion across cell can be affected by temperature, concentration, SA greater : volume
DIFFUSION
-random -movement of particles in both directions down concentration gradient -smaller non-polar molecules Ex. O2, CO2 |
FACILITATED TRANSPORT
-diffusion of particles through a protein channel -[high] -> [low] -smaller polar molecules Ex. glucose |
OSMOSIS
-diffusion of water -polar molecules Ex. Intestine |
Hypotonic
[Low]
Isotonic
[Even]
Hypertonic
[High]
Active
Requires ATP, movement against gradient.
Requires ATP, movement against gradient.
1. Moves smaller particles
2. Against concentration gradient [low] -> [high]
3. Uses ATP (energy)
4. Either polar or non-polar
Examples
Na K pump and nervous system
Iodine in our thyroid gland
Active Transport with Vesicle
Endocytosis- engulfing, taking in material (white blood cells)
Phagocytosis- eating
Pinocytosis- drinking
Exocytosis- material exiting cells (secretory pathway)
2. Against concentration gradient [low] -> [high]
3. Uses ATP (energy)
4. Either polar or non-polar
Examples
Na K pump and nervous system
Iodine in our thyroid gland
Active Transport with Vesicle
Endocytosis- engulfing, taking in material (white blood cells)
Phagocytosis- eating
Pinocytosis- drinking
Exocytosis- material exiting cells (secretory pathway)