D1.2 protein synthesis

Question 1

what are the steps in protein synthesis

Answer 1

transcription
splicing
translation
protein modification and folding

Question 2

explain the process of transcription

Answer 2

first step in protein synthesis
happens in nucleus
mRNA is formed from a dna strand (anti-sense) through complementary base paring
uses enzyme called RNA polymerase (catalyses phosphodiester bonds between free RNA nucleotides to form and RNA polynucleotide= the mRNA)
input= DNA
Output=mRNA
molecules used= rna polymerase and rna nucleotides

Question 3

explain process of splicing

Answer 3

second step in protein synthesis
post transcriptional modification
processes mRNA to form a mature mRNA
mRNA leaves the nucleus and enters the cytoplasm
non protein coding regions of the RNA strand are removed

Question 4

explain process of translation

Answer 4

thrid step in protein synthesis
happens in cytoplasm
polypeptide is formed from mRNA
uses ribosome to form peptide bonds between amino acids
tRNA is used to bring specific amino acids thus free amino acids are used

RNA molecules used as a code for protein assembly at the ribosome
input= mRNA
output=Protein
molecules used= ribosome, amino acid, tRNA, tRNA activating enzyme

Question 5

explain protein modification and folding

Answer 5

gives output to functional protein
post translational modification
protein folding of the 2nd to the 4th structure
addition of chemical groups (sugar, lipid, methyl, acethyl, phosphate etc.