RNA

Question 1

What is RNA?

Answer 1

RNA is single stranded, it makes a template for DNA replication. In RNA Thymine is replaced with Uracil, this is a pyrimidine and pairs with Adenine.

Question 2

Define codon?

Answer 2

Sequence of 3 bases on mRNA that code for a single amino acid.

Question 3

Define genome?

Answer 3

A complete set of genes in a cell.

Question 4

Define proteome?

Answer 4

The full range of proteins produced by the genome.

Question 5

Define anticodon?

Answer 5

The base sequence on tRNA.

Question 6

What happens when a polypeptide is required?

Answer 6

The triplet code of its gene is convert into a molecule of mRNA via transcription, translation comes later.

Question 7

mRNA description?

Answer 7

Single stranded, short, alpha helix shape, contains ribose sugar, it’s base pairings are A and U, C and G. It’s function is to create a template and it’s located in the nucleus and travels to the ribosome via the cytoplasm.

Question 8

tRNA description?

Answer 8

It is single stranded, shorter and a clover leaf shape. It contains ribose sugar and its base pairings are A and U, C and G miss function is to deliver the amino acid to the ribosome and it’s located in the cytoplasm.

Question 9

Transcription (first)?

Answer 9

RNA polymerase acts on a specific region which breaks the hydrogen bonds. The RNA polymerase then travels along the template strand. Nucleotides join from the nucleus. The RNA polymerase them travels along the DNA stand building a pre mRNA molecule from the template strand until the RNA polymerase reaches the stop codon. It then detached and the pre mRNA is released introns were cut out leaving just the exons, this is called splicing (it doesn’t occur in prokaryotes). The mRNA is produced to go onto translation.

Question 10

DNA to mRNA codons example?

Answer 10

During transcription the mRNA is built up by the complementary base pairing, using the DNA as a templates. The DNA bases were converted into mRNA codons.

DNA: TAC GCA GAT TAC
mRNA: AUG CGU CUA AUG

Question 11

Translation?

Answer 11

Once a molecule of mRNA has been transcribed it moves out of the nucleus via a nuclear pore into the cytoplasm where the mRNA combines with a ribosome. tRNA molecules attach to the ribosome and their anticodon a pair up with the complementary mRNA codon. The amino acids are transported by the tRNA which link together and the tRNA molecule returns to the cytoplasm. Then the next tRNA molecule enters. The ribosome moves along the mRNA and amino acids continue to join together until all the codons have been translated and the polypeptide is complete. ATP is used to from the peptide bonds.