GENE EXPRESSION

Question 1

what is involved in gene expression

Answer 1

• Gene expression involves the transcription and translation of DNA sequences.
• only a fraction of the genes are expressed

Question 2

Transcription and translation involves three
types of RNA (mRNA, tRNA and rRNA)

Answer 2

• RNA is single-stranded and is composed of
  nucleotides containing ribosome sugar,
• phosphate and one of four bases: cytosine,
  guanine, adenine and uracil.

Question 3

the structure and function of mRNA and a codon

Answer 3

• carries a copy of the DNA code from the nucleus to the ribosome
• mRNA is transcribed from DNA in the nucleus and translated into proteins in the cytoplasm
• codon: a triplet of bases that code for a specific amino acid

Question 4

the structure and function of tRNA

Answer 4

• folds due to complementary base pairing
• Each tRNA molecule carries its specific amino acid to the Each tRNA
• has an anti codon (an exposed triplet of bases) at one end and
  an attachment site for a specific amino acid at the other end

-. Ribosomal RNA (rRNA) and proteins form the ribosome

Question 5

The role of RNA polymerase in transcription of DNA into primary mRNA
transcripts

Answer 5

• 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