Structure Of RNA

Question 1

How does RNA differ in structure to DNA?

Answer 1

• the pentose sugar in RNA is ribose but in DNA is deoxyribose
• Uracil replaces Thymine
• RNA is single stranded opposed to DNA which is double stranded
  —> no complementary base pairing

Question 2

State the three types of RNA

Answer 2

1. Ribosomal RNA (rRNA)
2. Messenger RNA (mRNA)
3. Transfer RNA (tRNA)

Question 3

Describe the structure and function of mRNA.

Answer 3

Structure:
- single stranded (no hydrogen bonds)
- polynucleotide strands vary in length and base sequence
- 3 bases is called a codon

Function:
- are complementary copies of DNA gene sequences
- the form in which genetic code is carried to the ribosomes to undergo protein synthesis

Question 4

Describe the structure and function of tRNA.

Answer 4

Structure:
- single polynucleotide strand with a fixed length
- clover leaf shape due to hydrogen bonding
- has an amino acid attachment site
- 3 exposed bases known as an anticodon which are complementary to mRNA codons

Function:
- transport specific amino acids to ribosomes during protein synthesis