topic 3
Transport through membranes
- Fluid mosaic model
- Diffusion
- Active transport
- Co-transport
- Osmosis
- Bulk transport
, Fluid mosaic model
- Phospholipids are an important component of cell
surface membranes due the fact they can form
bilayers.
- Due to lipids hydrophilic and hydrophobic nature it
forms 2 layers with the hydrophobic tails pointing
towards each other and the hydrophilic heads on
the outside.
- Phospholipid membranes allow lipid soluble
molecules through it but not water-soluble
molecules.
- Protines are scattered within the membrane and
there are 2 types intrinsic and extrinsic.
- Intrinsic Protines span across both the layers in the
membrane and are used for transport of molecule
passively or actively.
- Extrinsic proteins are on either surface of the
membrane and are used for structural stability.
- The fluid mosaic model was proposed by singer
and Nicolas in 1972 and was named due to the fact
the phospholipid molecules can move within the
layer (fluid) and the scattered Protines within the
bilayer (mosaic)
- Plant and animal cells contain glycoproteins,
glycolipids and sterols (cholesterol in animals)
- Membrane impurities make the membrane more
stable at high temperatures and more fluid at
lower temperatures
- The carbohydrate layer around animal cells is
called glycoclyx hand is involved in hormone
recapturers and cell recognition.
- Small molecules such as oxygen can move
between the membrane molecules so diffuse
across the membrane.
Transport through membranes
- Fluid mosaic model
- Diffusion
- Active transport
- Co-transport
- Osmosis
- Bulk transport
, Fluid mosaic model
- Phospholipids are an important component of cell
surface membranes due the fact they can form
bilayers.
- Due to lipids hydrophilic and hydrophobic nature it
forms 2 layers with the hydrophobic tails pointing
towards each other and the hydrophilic heads on
the outside.
- Phospholipid membranes allow lipid soluble
molecules through it but not water-soluble
molecules.
- Protines are scattered within the membrane and
there are 2 types intrinsic and extrinsic.
- Intrinsic Protines span across both the layers in the
membrane and are used for transport of molecule
passively or actively.
- Extrinsic proteins are on either surface of the
membrane and are used for structural stability.
- The fluid mosaic model was proposed by singer
and Nicolas in 1972 and was named due to the fact
the phospholipid molecules can move within the
layer (fluid) and the scattered Protines within the
bilayer (mosaic)
- Plant and animal cells contain glycoproteins,
glycolipids and sterols (cholesterol in animals)
- Membrane impurities make the membrane more
stable at high temperatures and more fluid at
lower temperatures
- The carbohydrate layer around animal cells is
called glycoclyx hand is involved in hormone
recapturers and cell recognition.
- Small molecules such as oxygen can move
between the membrane molecules so diffuse
across the membrane.
