Transcription of DNA to RNA

Question 1

RNA falls into three major categories

Answer 1

Messenger RNA (mRNA)
Transfer RNA (tRNA)
Ribosomal RNA (rRNA)

Question 2

copies the genetic code from the DNA into a form that can be read and used to make proteins. It transmits genetic information from the nucleus to the cell’s cytoplasm

Answer 2

mRNA (messenger RNA)

Question 3

is situated in the cytoplasm of a cell, where we can find the ribosomes. It leads the translation of mRNA into proteins.

Answer 3

rRNA (Ribosomal RNA)

Question 4

transfers amino acids to the ribosome that matches to each three-nucleotide codon of rRNA. The amino acids then can be combined and processed to make polypeptides and proteins

Answer 4

tRNA (Transfer RNA)

Question 5

in protein synthesis is the process where RNA is made from the DNA by copying the base sequence of the double stranded DNA into a piece of a single stranded nucleic acid.

Answer 5

Transcription

Question 6

The transcription process is catalyzed by the enzyme?

Answer 6

RNA Polymerase

Question 7

takes place in the cell’s nucleus. This process uses DNA as a model to make an RNA (mRNA) molecule. During this, a strand of mRNA is made that corresponds to a strand of DNA. Just like DNA replication, transcription also occurs in three major steps: initiation,elongation, and termination.

Answer 7

Transcription of DNA to form RNA

Question 8

It transpires when the enzyme RNA polymerase binds to a specific region of a gene which is called the promoter with the help of proteins called ‘transcription factors’. This signals the DNA double strand to unwind and open so the RNA polymerase enzyme can ‘‘read’’ the bases found in one of the DNA strands. With the open strands, one is considered as the template strand (anti-sense strand) and this will be used to generate the mRNA. The other is called the non-template strand (sense strand). After reading the bases, the RNA polymerase enzyme is now ready to make a strand of mRNA with a complementary sequence of bases.

Answer 8

Step 1: Initiation

Question 9

is the adding of nucleotides to the mRNA strand. RNA polymerase reads the opened DNA strand and forms the mRNA molecule with the use of complementary base pairs. There is a short time during this process when the newly formed RNA is bound to the opened DNA. During this process, an adenine (A) in the DNA binds to an uracil (U) in the RNA. RNA polymerase does not need a primer during this process. It simply initiates the mRNA synthesis from the starting point and then moves downstream reading the anti-sense strand from 3’ to 5’ and generating the mRNA from the 5’ to 3’ end as it goes. Unlike helicase enzyme in DNA replication, RNA polymerase zips DNA back up as it goes keeping only 10-20 bases exposed one at a time.

Answer 9

Step 2: Elongation

Question 10

This happens when RNA polymerase enzyme reaches a stop or termination sequence in the gene. When the stop sequence or stop codon is reached, the enzyme detaches from the gene. The mRNA strand is now produced, and it detaches from DNA. It carries with it the information encoded in the gene

Answer 10

Step 3: Termination