Gene Expression

Question 1

Messenger RNA Basic

Answer 1

Carries a copy of the DNA code from the nucleus to the ribosome

Question 2

Transfer RNA Basic

Answer 2

Each tRNA molecule carries its specific amino acid to the ribosome

Question 3

Ribosomal RNA

Answer 3

rRNA and proteins form a ribosome

Question 4

Transcription RNA Polymerase

Answer 4

RNA polymerase moves along DNA unwinding the double helix and breaking the hydrogen bonds between the bases. RNA polymerase synthesises a primary transcript of mRNA from RNA nucleotides by complementary base pairing.

Question 5

RNA Splicing forms

Answer 5

Mature Transcript

Question 6

Introns

Answer 6

The introns of the primary transcript are non- coding regions and are removed.

Question 7

Exons

Answer 7

The exons are coding regions and are joined together to form the mature transcript.

The order of the exons is unchanged during splicing.

Question 8

Can Different proteins can be expressed from one gene, as a result of alternative RNA splicing?

Answer 8

Yes

Question 9

tRNA involvement in translation

Answer 9

tRNA is involved in the translation of mRNA into a polypeptide at a ribosome.

Translation begins at a start codon and ends at a stop codon.

Anticodons bond to codons by complementary base pairing, translating the genetic code into a sequence of amino acids.

Peptide bonds join the amino acids together.

Each tRNA then leaves the ribosome as the polypeptide is formed.

Question 10

Different mature mRNA transcripts are produced from the same primary transcript depending on

Answer 10

Which exons are retained

Question 11

Amino Acids

Answer 11

Amino acids are linked by peptide bonds to form polypeptides. Polypeptide chains fold to form the three-dimensional shape of a protein, held together by hydrogen bonds and other interactions between individual amino acids. Proteins have a large variety of shapes which determines their functions