Transcription and Translation

Question 1

What are the two main stages of protein synthesis?

Answer 1

Translation and Transcription

Question 2

What is transcription?

Answer 2

Transcription is when one gene on the DNA is copied into mRNA.

Question 3

What is translation?

Answer 3

Translation is when the mRNA joins with a ribosome and corresponding tRNA molecules bring the specific amino acid the codon codes for.

Question 4

Process of transcription (5)

Answer 4

1)DNA helicase breaks the hydrogen bonds between the DNA bases.
2)One strand of DNA acts as a template.
3)Free RNA nucleotides align by complementary base pairing.
4)RNA polymerase joins adjacent RNA nucleotides by phosphodiester bonds.
5)Pre-mRNA is spliced to form mRNA.

Question 5

Where does transcription occur?

Answer 5

In the nucleus.

Question 6

Why can’t DNA just leave the nucleus alone?

Answer 6

It is too big to leave and attach to a ribosome. Also, in the cytoplasm, there are enzymes that could damage the DNA.

Question 7

Once the mRNA is modified how does it leave the nucleus?

Answer 7

Through the nuclear pores.

Question 8

When is pre-mRNA modified?

Answer 8

After transcription.

Question 9

How is pre-mRNA modified?

Answer 9

Introns are spliced out by a protein called splicesome. This leaves behind just the exons which are the coding regions.

Question 10

How does translation occur? (5)

Answer 10

1)mRNA attaches to ribosomes.
2)tRNA anticodons bind to complementary mRNA codons.
3)tRNA brings a specific amino acid and the amino acids are joined by peptide bonds with the use of ATP.
4)tRNA is released.
5)The ribosome moves along the mRNA to form the polypeptide.

Question 11

What happens after translation?

Answer 11

The polypeptide chain will enter the golgi body for modification and folding.