Transcription and Transalation

Question 1

Define genome.

Answer 1

Complete set of genes in a cell or organism.

Question 2

Define proteome.

Answer 2

Full range of proteins a cell is able to produce.

Question 3

Describe the structure of mRNA.

Answer 3

Long, single strand with a base sequence complementary to DNA. Each codon matches triplet on DNA and tRNA.

Question 4

Describe the structure of tRNA.

Answer 4

Single strand folded into a clover leaf shape. One end extends for amino acid to attach to. On opposite end, anticodon loop is specific to amino acid that attaches.

Question 5

What is transcription?

Answer 5

Production of mRNA from DNA.

Question 6

Describe transcription.

Answer 6

1. DNA Helicase breaks hydrogen bonds between complementary bases and DNA uncoils.
2. Both DNA strands become templates to make mRNA from.
3. RNA Polymerase forms phosphodiester bonds by condensation reactions to join adjacent nucleotides and free nucleotides line up by complementary base pairing.
4. (EUKARYOTES ONLY) Pre-mRNA is spliced which is where introns are cut out, only leaving exons on mRNA strand.
5. mRNA moves out of nuclear pores into cytoplasm.

Question 7

What is transalation?

Answer 7

The production of polypeptides from a mRNA strand.

Question 8

Describe transalation.

Answer 8

1. Ribosome attaches to start codon on mRNA strand.
2. tRNA collects amino acids from cytoplasm and attaches to mRNA by complementary base pairing.
3. Amino acids are joined with peptide bond in ribosome (requires energy from ATP).
4. tRNA detaches and is free to find another amino acid.
5. Ribosome moves along mRNA strand, process repeats until stop codon reached, leaving a polypeptide chain.