Introduction to Transcription and Translation

Question 1

What are genes?

Answer 1

Short segments/sequences of DNA that contain genetic instructions that specify the AA sequences of proteins

Question 2

What acts as the bridge between genetic information (DNA) and a protein?

Answer 2

Ribonucleic acid

Question 3

How does RNA acts a bridge between DNA and a protein?

2

Answer 3

RNA copies a short segment of DNA by using it as a template

This is then used in the synthesis of the protein

Question 4

Which happens first translation or transcription?

Answer 4

Transcription first then translation

Question 5

List the order of the flow of genetic information.

5

Answer 5

DNA

Transcription

mRNA

Translation

Protein

Question 6

Define transcription

Answer 6

A portion of DNA nucleotide sequence (gene) is copied into a RNA nucleotide sequence

Question 7

Where does transcription occur in eukaryotes?

Answer 7

Occurs in the nucleus

Question 8

Where does transcription occur in prokaryotes?

Answer 8

Occurs in the cytoplasm

Question 9

Define translation.

2

Answer 9

The synthesis of polypeptide under direction of RNA

Formation of amino acid chains - proteins

Question 10

Where does translation occur?

Answer 10

Cytoplasm

Question 11

Why does transcription occur in the nucleus of eukaryotic cells?

Answer 11

Because the DNA of eukaryotes is protected by the nucleus

Question 12

What must be cut out of eukaryotic DNA before translation?

Answer 12

Non-coding DNA must be cut out

Question 13

What is non-coding DNA also called?

Answer 13

Introns

Question 14

What is coding DNA also called?

Answer 14

Exons

Question 15

What must be done between transcription and translation in eukaryotic cells?

Answer 15

mRNA processing is required

Question 16

What are the two main differences between RNA and DNA?

2

Answer 16

RNA is single stranded and a short polymer

DNA is double stranded and a long polymer

Question 17

What is messenger RNA?

Answer 17

RNA molecules copied from genes which direct synthesis of proteins

Question 18

Give three examples of RNAs

Answer 18

Transfer RNA (tRNA)

Ribosomal RNA (rRNA)

Small nuclear RNA (snRNA)

Question 19

How does transcription begin?

Answer 19

It begins with opening and unwinding of a small portion of DNA to expose the bases on each DNA strand

Question 20

How does DNA replication differ from transcription?

4

Answer 20

The RNA strand does not remain hydrogen bonded to it’s DNA template

The DNA helix reforms and displaces the RNA chain

RNA copies only from a limited region of DNA

RNA polymerases are used instead of DNA polymerases

Question 21

Why does RNA copies only from a limited region of DNA?

Answer 21

This is because RNA molecules are much shorter than DNA

Question 22

What does RNA polymerase do?

Answer 22

It catalyses the formation of the phosphodiester bonds that link nucleotides together and form the sugar-phosphate backbone of the RNA chain