Structure and function of RNA

Question 1

RNA

Answer 1

Ribonucleic acid (RNA) is a second type of nucleic acid in the cell. RNA is made of nucleotide sub-units and is single stranded.
RNA plays a vital role in the production of protein from the code in the DNA.

Question 2

Differences between DNA and RNA

Answer 2

RNA nucleotides are similar in structure to those of DNA. However in RNA ribose sugar replaces the deoxyribose sugar of DNA and the base uracil replaces thymine.

Question 3

Types of RNA

Answer 3

There are three types of RNA involved in gene expression:

1. MessengerRNA(mRNA)
2. TransferRNA(tRNA)
3. RibosomalRNA(rRNA)

Question 4

mRNA

Answer 4

Messenger RNA is formed in the nucleus, from free nucleotides. It is transcribed from DNA.
mRNA carries a copy of the DNA code from the nucleus to the ribosome in the cytoplasm (where protein synthesis occurs).
The bases which make up mRNA are ‘read’ at the ribosome in groups of three called codons.

Question 5

tRNA

Answer 5

Transfer RNA molecules carry specific amino
acids, bringing them to the ribosome to build proteins.
tRNA molecules fold due to complementary base pairing to form a 3-D shape. Only three bases are exposed, this is called an anticodon. At the other end there is a site for a specific amino acid to attach.

Question 6

rRNA

Answer 6

Ribosomal RNA molecules combine with

proteins to form the ribosome.