Friday, 17 February 2012

The production of extracellular enzymes


In the nucleus, the DNA double helix unwinds & exposes its two strands for the synthesis of mRNA strand.
The mRNA (messenger RNA) leaves the nucleus through the nuclear pore and moves to a ribosome.
The mRNA attaches itself to the ribosome.
Proteins are synthesised & transported through the space within the rough ER.
Proteins depart from rough ER wrapped in vesicles (transport vesicle) that bud off from the membrane.
The transport vesicle then fuse with Golgi apparatus. The proteins are further modified, packaged, sorted (eg. carbohydrates are added to proteins --> glycoproteins)
Secretory vesicles then bud off from the Golgi apparatus & travel to plasma membrane.
They then diffuse with the plasma membrane before being released outside.