Select the answer that represents the correct order of structures involved in protein synthesis and secretion.

a. nucleus, rough er, condensing vesicle, golgi apparatus, transitional vesicle
b. nucleus, smooth er, transitional vesicle, golgi apparatus, secretory vesicle
c. nucleus, golgi apparatus, transitional vesicle, rough er, secretory vesicle
d. nucleus, rough er, transitional vesicle, golgi apparatus, secretory vesicle

d. Nucleus, rough ER, transitional vesicle, Golgi apparatus, secretory vesicle

Explanation:

The process of protein synthesis begins in the nucleus with transcription. Specific mRNA of the complementary DNA code of the protein  to be   synthesize   is copied.  The mRNA binds to the DNA molecule template  by enzyme RNA polymerase; this enzyme  binds the mRNA at the promoter site of the DNA and the bases joined together  by hydrogen bonds.This is transcription. When  full complementary of the mRNA from the template DNA has been copied they are releases by the enzyme RNA polymerase at terminator. The mRNA leaves the nucleus through the nuclear pore for the nucleus.

The mRNA binds to the ribosomes which are mostly attached to the endopalsmic reticulum, and are therefore called rough endoplasmic reticulum or  drifting freely in the cytoplasm. tRNA molecules are  present in the cytoplasm. they have two ends; one end for binding with triplet of bases(anticodons) and the other end for amino acid attachments on the mRNA(codons). This is initiation, and it takes place in the cytoplasm.

Trasnslation

The complementary binding leads to formation of sequence of amino acid  polypeptide chains,.it is catalysed by the enzyme peptidyl transferase,on the small ribosome  small sub units; in presence of ATPs, the first codon is usually AUG,  for the amino acid methionine. It terminates at the stop condon ;UAA,UAG It is called translation, because the mRNA is translated to polypepetide chains of amino acids  on the small unit of ribosomes, the location.

The polypeptide chains of amino acids  are transported through the  transport vesicles to the Golgi  cisternae ( Golgi apparatus).for processing and sorting.

 They are moved by cisternae migration to trans-golgi reticulum,,where the  are sorted out,From here they are transported to the trans-Golgi network;for onward  transportation  into the secretory vesicles and   transport vesicles. The latter fused with the plasma membrane , and secreted to the outside by Exocytosis.

Proteins  stored in the secretory vesicles usually  stimulus for exocytosis, thus are not immediately available for secretion

a physical change is being made.