Protein Transport (3.3)

Question 1

Describe the process of protein transport and manufacture (4/5 marks)

Answer 1

• Starts with transcription in the nucleus with mRNA leaving via nucelar pores after this process occurs.
  -mRNA joins onto ribsomes of rough endoplasmic reticulum where translation occurs to form a polypeptide.
  -The protein formed moves into the the RER and travels through the membrane bound sacs of the ER. As it travels through the protein is processed and assumes its tertiary structure.
  -When reaching the end of the RER a vesicle containing the protein is pinched off the ER sac. This transport vesicle moves from the ER to the golgi apparatus.
  -Transport vesicle fuses with receiving face and protein enters golgi apparatus. This is where proteins are modified.
  -Once modified, the now modified protein enters a transport vesicle and is pinched off a seperate face of the golgi.
  -This vesicle leaves the golgi apparatus and fuses with the cell surface membrane to release its contents via exocytosis.