Sub-cellular processes

Question 1

Steps in making and secreting a protien

Answer 1

1. gene that has coded instruction for a protien (e.g insulin) housed on chromatin in the nucleus is transcribed into a length of RNA = mRNA
2. Many copies of this mRNA are made and they pass out of pores in the nucleur envelope to the ribosomes
3. At the ribosomes the instructions are translated and insulin molecules are assembled
4. Insulin molecules pass along into the cisternae of the rough endoplasmic reticulum along hollow sacs
5. Vesicles with insulin inside are pinched off from the RER and pass via microtubulues & motor protiens to the golgi apparatus
6. Vesciles fuse with the golgi aparatus where the insulin protien molecules may be modified for release
7. Inside vesicles pinched off from golgi aparatus these molecules pass to plasma membraine
8. the vesicles and plasma membraine fuse & the insulin is released to the outside of the cell