Genes and Proteins

Question 1

Transcription vs translation

Answer 1

Transcription = DNA –> RNA
Translation = RNA –> protein

Question 2

Prokaryotic transcription

Answer 2

• Transcription factors bind to the promoter region upstream of the gene
• RNA polymerase carries out transcription
• consensus sequences

Question 3

Eukaryotic transcription

Answer 3

• mRNA = RNA polymerase II
• transcription factors form a complex in the promoter region of the gene
• RNA polymerase II binds and synthesizes RNA that is antiparallel and complementary to the template (not coding) strand of the DNA; DNA is read from 3’ to 5’

Question 4

mRNA processing

Answer 4

• 5’ cap
• 3’ pol-A tail
• Removal of introns

Question 5

snRNPs or snurps

Answer 5

they recognize the intro-exon boundaries and remove the introns

Question 6

Alternative splicing

Answer 6

Exons are reattached in a variety of sequences

Question 7

tRNA

Answer 7

• cloverleaf shape
• bring in amino acids to the ribosome during translation
• one part attaches to amino acid
• the other part has an anticodon that is complementary to the mRNA codon (group of 3 bases that code for specific amino acids)

Question 8

Ribosomes

Answer 8

• protein and rRNA
• read mRNA from 5’ to 3’
• pro: 50S+30S=70S
• eu: 60S+40S=80S

Question 9

tRNA binding sites in a ribosome

Answer 9

• A - binds the tRNA carrying the next amino acid
• P - binds to the tRNA attached to the growing peptide chain
  
  • Peptidyl transferase transfers peptides from P site to A site
• E - binds the tRNA that carried the last amino acid

Question 10

Start codon

Answer 10

AUG that codes for methionine