Yo dawg, I'm slightly confused on some organelles, I keep reading different points on them in different books. The main thing I have trouble understandding is what it is that the nucleus does in technical terms that i need for the exam, what does it have to do with protein synthesis? I THINK it produces mRNA and passes this out of the nuclear pores into the RER where it is used by ribosomes to make proteins? Does the nucleus contain amino acids or is it just the cytopplasm?
Then what exctly do the RER and SER do? Transport proteins and lipids throughout the cell? The golgi apparatus packages and labels proteins and lipids for endo / exocytosis yes?
Sorry if it's a lot to ask, I'd jus like a clear explanation of how a protein is synthesised using these organelles and a rundown of essential thigns i need to know about the seperate organelles if possible.
help with cell structures / protein synthesis unit 1 AQA Watch
- Thread Starter
- 22-12-2010 22:07
- 23-12-2010 17:16
Right, the nucleus is made up of the nucleolus- which produces ribosomes, the chromatin- material consisting of DNA and proteins, and the nuclear envelope- the double membrane enclosing the nucleus, has pores and is continous with the ER.
I'll give you a step by step guide to protein trafficking:
1. Proteins made on the ribosomes enter through the rough endoplasmic reticulum
2. As the proteins move through the ER space, the polypeptide chain bends until it reaches its precise 3D shape
3. A transport vesicle buds off the ER space
4. It takes the protein with it
5. The vesicles fuse to form the flattened sacs of the Golgi apparatus
6. The proteins are modified within the Golgi apparatus
7. Part of the Golgi apparatus’ membrane becomes a secretory vesicle
8. The secretory vesicle containing the protein gets pinched off the Golgi apparatus
9. The secretory vesicle fuses with the cell surface membrane through exocytosis
10. Thus, it releases the protein out of the cell
I hope that helped.