a. How does the information found in DNA become the instructions for constructing proteins?
The information in DNA is transribed into mRNA. The mRNA flows from the cytosol into the nucleus through its nuclearpores and undergoes transcription. Transcription is the process by which genetic information is copied from DNA into RNA. Transcription
b. How does the process of transcription work?
Transcription begins as mRNA binds to a specific region of a DNA molecule called the promoter region. The DNA seperates and the mRNA uses one of its strains as a template to copy the genetic informatioin. After the DNA has seperated an enzyme called RNA polymerase attaches to the region of transcription and adds new, complementary nucleotides to the mRNA. However, when transcription occurs the nucleotide uracil binds with adenine for mRNA; instead of adenine binding with thymine. Transcription continues until the RNA polymerase reaches the termination signal and releases the mRNA into the cytosol where it can tansfer the genetic information to the ribosomes.
c. How does the process of translation work?
First, translation is the process of making proteins from information incoded in mRNA. Translation begins as mRNA migrates to the ribosomes at the site of protein synthesis. As the mRNA docks at the ribosome tRNA brings the correct amino acid to the correct codon on the mRNA. However, tRNA doesn't bring any amino acids until the start codon AUG, for the amino acid methionine, in read on the mRNA. After AUG is read the process doesn't stop unitl a stop codon of UAA, UAG, or UGA is read on the mRNA. When the amino acid reaches its destination it breaks away and attaches to a growing polypeptide chain which will become a protein when completed.
Information provided by: http://learn.genetics.utah.edu/units/basics/transcribe/