B1.2.2 Transcription Nd Translation

Question 1

How is a copy of DNA made?

Answer 1

DNA can’t leave the nucleus of a cell since its too big.
Instead a copy of it is made called messenger RNA
This is like a single strand.

Question 2

What is the process of translation (6)

Answer 2

mRNA attaches to a ribosome.
The mRNA bases are read in triplets.
Each triplet codes for an amino acid.
Each amino acid is joined together to make a polymer chain.
sequence of amino acids determines how the protein will fold

Question 3

What is the process of transcription

Answer 3

DNA unzips
Free RNA bases pair in complementary pairs to form mRNA( RNA doesn’t have thymine, it is replaced with uracil, U)
mRNA detaches from the DNA and leaves the nucleus where it travels to the ribosome

Question 4

Name some differences between DNA and mRNA

Answer 4

DNA has deoxyribose sugars whereas mRNA has ribose sugars
DNA nucleobases are AGCT whereas in mRNA they are AGCU
DNA is double stranded and mRNA is single stranded
One is formed in DNA replication and the other is formed during transcription

Question 5

Name two differences between transcription and translation

Answer 5

Transcription- Uses a strand of DNA to build a molecule of mRNA
Translation- Uses mRNA to build an amino acid chain
Transcription- occurs in nucleus
Translation- occurs in cytoplasm/ ribosome

Question 6

Suggest why the order of nucleotides in DNA and mRNA is called a triplet code

Answer 6

Each group of three bases in mRNA constitutes a codon, and each codon codes for a particular amino acid (hence, it is a triplet code).