Genomics (easy)

Question 1

Explain how asRNA therapy affects Tsl [2]

Answer 1

1. mRNA binds asRNA via CBP
   » form dsRNA molecules
2. Ribosomes cannot bind dsRNA molecules

Question 2

Explain how DNA in chromatin is protected from digestion by DNase [2]

Answer 2

1. Negatively charged DNA binds positively-charged histone (Lys tails)
2. AS of DNase unable to access and bind DNA

Question 3

Explain the effects of the deletion of the enhancer [2]

Answer 3

1. Activators cannot bind
2. Cannot interact with GTFs and RNA pol
   » to form a stable Tsc IC

Question 4

State why bacteria do not carry out PTM [1]

Answer 4

No RER and GA

Question 5

Describe how a spliceosome produces a mature mRNA [2]

Answer 5

1. snRNA recognises and binds to specific splice sites at intron-exon boundaries via CBP
2. snRNPs associate to form spliceosomes
   » excise introns by cleaving PPDs, join exons

Question 6

Outline how PG is synthesised from its mRNA [3]

Answer 6

1. RIBOSOME binds 5’ of mRNA
2. tRNA anticodon binds mRNA codon via CBP
3. PEPTIDYL TRANSFERASE
4. Specific codon sequence&raquo_space; specific AA sequence

Question 7

Explain why Tsl can occur simultaneously with Tsc in prokaryotes [2]

Answer 7

1. No membrane-bound nucleus
   » ribosomes can attach mRNA immediately
2. No need for PTM

Question 8

Name the 4 enzymes involved in SCR

Answer 8

Helicase, topoisomerase

DNA pol, DNA ligase

Question 9

Explain why double-stranded structure allows for “backup of the code} [1]

Answer 9

One strand serves as a TEMPLATE for the repair of the other via CBP