Question

Explain the structure, function and types of RNA. <!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> [Textbook question 3d pg no.193]

Answer 1

Answer

Structure of RNA can be described as RNA is single-stranded, each strand is made up of ribonucleotides that are linked by phosphodiester bonds.

• A ribonucleotide in the RNA chain contains

1. Ribose (the Penrose sugar)
2. One of four nitrogenous bases (A, U, G and C) uracil replaces Thymine.
3. A phosphate group.

Types of RNA:

There are four types of RNA.

• mRNA or messenger RNA. These are responsible for encoding the amino acid sequence of a polypeptide .
• tRNA – It brings amino acids to ribosomes during translation.
• rRNA or ribosomal RNA. rRNA along with ribosomal proteins make ribosomes.

Functions of RNA are as follows

1. mRNA carries genetic information copied from DNA in the form of a series of three base code words.
2. tRNA carries the growing end of polypeptide chain if next for code word on mRNA Calls for it. At each step the correct tRNA with it’s attached amino acid is selected.
3. rRNA is associated with a set of proteins to form ribosomes rRNA along with mRNA catalyze assembly of amino acids into protein chains. rRNA is also responsible for binding tRNA and various molecules necessary for protein synthesis.