Molecular Genetics

Antisense RNA  is a single-stranded RNA which is complementary to a messenger RNA strand transcribed within a cell. In tobacco plants resistant to nematodes, the DNA produces both sense and antisense RNA.

This mutation causes no change in the final protein product and can only be identified by sequencing the gene. Most amino acids that make up a protein are encoded by several different codons.

It is a DNA sequence present in the promoter area of genes in archaea and eukaryotes. Around 24% of human genes contain a TATA box within the core promoter.

The site of mRNA synthesis is nucleus. It is synthesised from DNA template in a process called transcription.

tRNA ferries amino acids to ribosomes for protein synthesis. As it functions in transfer of amino acids, it is therefore called transfer RNA.

The site for synthesis of proteins, i.e. ribosomes is synthesised by rRNA.

Hepatitis C is a single stranded RNA virus.

tRNA is a very small molecule and thus, easily solubilises in cytoplasm.

7-Methyl guanosine triphosphate caps the 5' terminal end of mRNA. This cap is involved in recognition of mRNA by translating machinery.

Both 5' cap and 3' tail impart stability to mRNA by protecting it from specific exonucleases.

The 3' end of most mRNA's has a poly A tail. It prevents the attack by 3' exonucleases.

25% of hnRNA is processed to mature mRNA.

Heterogeneous nuclear RNA acts as immediate precursor for synthesis of mRNA. Mature mRNA is formed from hnRNA by capping, tailing, splicing and base modification.

tRNA acts as an adapter for the translation of the sequence of nucleotides of the mRNA into specific amino acids.

Each single tRNA shows extensive internal base pairing and acquires a clover leaf-like structure. The structure is stabilised by hydrogen bonding between the bases and is a consistent feature.