2.1.7 Organelles & the Production of Proteins

Question 1

what are the organelles that are involved in protein synthesis?

Answer 1

-nucleus
-ribosomes
-rER
-Golgi apparatus
-plasma membrane

Question 2

what are the stages of protein synthesis in the nucleus?

Answer 2

-the DNA from the nucleus is copied into a molecule of mRNA via a process known as transcription
-he mRNA strand leaves the nucleus through a nuclear pore and attaches to a ribosome on the rough endoplasmic reticulum

Question 3

what are the stages of protein synthesis in the rER?

Answer 3

-the ribosome ‘reads’ the genetic instructions contained within the mRNA and uses this code to synthesise a protein via a process known as translation
this protein then passes through the membrane into the cisternae (the inside spaceof the rough endoplasmic reticulum) to be folded and processed

Question 4

what are the stages of protein synthesis in the Golgi apparatus?

Answer 4

-the processed proteins are then transported to the Golgi apparatus in vesicles which fuse with the Golgi apparatus, releasing the proteins
-the Golgi apparatus modifies the proteins, preparing them for secretion

Question 5

what stages of protein synthesis involve the plasma membrane?

Answer 5

-the modified proteins are then packaged into vesicles and are pinched off
-these vesicles (containing the final proteins) fuse with the cell surface membrane, releasing the proteins by the process of exocytosis