DNA Transcription

Question 1

What is an Amino Acid?

Answer 1

Organic compounds that link together to create proteins
The specific proteins that are produced by a cell determine the structure, function and development of the cell

Question 2

What is Genetic Code?

Answer 2

The order of base pairs in a DNA molecule
Determines how the aas are strung together and how the proteins are made

Question 3

What is Gene Expression?

Answer 3

The transfer of genetic information from DNA to RNA to protein

Question 4

Where does Transcription occur in a Eukaryotic cell?

Answer 4

In the nucleus, and it uses mRNA
mRNA moves into the cytoplasm and directs the synthesis of a polypeptide (a chain of amino acids) with the
aid of transfer RNA (tRNA)

Question 5

What is a codon?

Answer 5

The series of 3 nucleotides used for each amino acid

Question 6

How is Genetic code interpreted?

Answer 6

In terms of the mRNA codon rather than the nucleotide sequence of the original DNA strand

Question 7

Why is the Genetic code redundant?

Answer 7

More than one codon can code for the same AA

Question 8

Genetic code stats

Answer 8

It’s continuous - no spaces or overlap
It’s nearly universal
Almost all living organisms build proteins with this genetic code

Question 9

What is Transcription?

Answer 9

When information in a segment of DNA is copied into mRNA
For each gene, only one strand of DNA is is transcribed - this is the sense strand
The strand that is not transcribed is the anti-sense strand
In a single molecule, either can serve as the sense strand for different genes

Question 10

How does Transcription work?

Answer 10

RNA Polymerase catalyses the synthesis of RNA
A sequence of nucleotides on the DNA molecule serve as a promoter region that tells RNA polymerase where to bind
Once the RNA polymerase has bound to the sense strand of DNA, it opens a section of the double helix
The enzymes then work their way along the DNA molecule and synthesize a strand of mRNA that is complimentary to the
sense strand of DNA
The DNA helix reforms behind the RNA polymerase complex
Like DNA polymerase, RNA polymerase works in 5’ - 3’ direction, adding nucleotides to the 3’ region of the previous nucleotide
Only one strand of DNA is being transcribed so there is no need for Okazaki fragment

Question 11

Termination in transcription

Answer 11

RNA polymerase stops when it gets a stop signal (aka termination sequence)
When RNA polymerase reads this stop signal, it detaches
mRNA strand is released, Double helix reforms