siRNA

Question 1

how does siRNA prevent/inhibit translation

Answer 1

• siRNA combines with proteins to form RISC (RNA inducing silencing complex)
• enzyme in the RISC hydrolyses the mRNA into smaller fragments
• so translation of mRNA cannot take place

Question 2

describe the structure of siRNA

Answer 2

• double stranded rna
• has complimentary base pairing (a+u, c+g)
• guanine on one strand forms hydrogen bonds with cytosine on other strand
• adenine on one strand forms hydrogen bonds with uracil on other strand

Question 3

describe how siRNA is formed from RNA

Answer 3

• double stranded RNA attatches to enzyme called DICER
• DICER hydrolyses the double stranded RNA into shorter fragments called siRNA
• one of the RNA strands is broken down so RISC contains single stranded siRNA