DNA/RNA/Transcription

Question 1

What are the stages of Transcription?

Answer 1

1- Hydrogen bonds between complimentary bases broken

2- One of the DNA strands is used as a template to make the mRNA molecule

3- RNA nucleotides align by complementary base pairing

4- Uracil (instead of Thymine) base pairs with Adenine

5- RNA polymerase joins adjacent nucleotides

6- By phosphodiester bonds

7- Pre mRNA is spliced (introns removed) to form mRNA

Question 2

Describe how a polypeptide is formed by translation of mRNA

Answer 2

1 - mRNA attaches to ribosome

2- tRNA anticodons bind to complementary mRNA codons

3- tRNA brings a specific amino acid

4- Amino Acids join by peptide bonds

5- Amino acids join with use of ATP

6- tRNA released

7- the ribosome moves along the mRNA to form the polypeptide.

Question 3

Give 2 structural differences between a molecule of mRNA and a molecule of tRNA

Answer 3

1- mRNA does not have hydrogen bonds, tRNA does

2- mRNA does not have an amino acid binding site, tRNA does

3- mRNA has more nucleotides than tRNA

4- mRNA has codons, tRNA has anticodons