Download Structure,Function of RNA

Structure,Function of RNA !!
RNA
RNA is a polymer of ribonucleotides, linked together by 5′ –
3′ phosphodiester linkage.
RNA strands for Ribonucleic acid.
It is a polymeric molecule implicated in various biological
roles in coding, decoding regulation and expression of genes.
DISTRIBUTION
RNA found in cytoplasm, ribosome and nucleus.
CHEMICAL STRUCTURE OF RNA
1. Each RNA molecule made up with ribonucleotide linkage
2. Each nucleotide is made up with 3 components
A phosphate group
A ribose sugar
A nitrogen base
3. Nitrogenous base hold together by covalent bonds
4. RNA molecule have two purine base (adenine, guanine) and
two pyrimidine base (uracil, cytocine)
5. Ribose sugar bonded with one nitrogen base form
Ribonucleoside,
and bind with phosphate group by phosphodiester
bond formed Ribonucleotide.
3. Many nucleotide molecules adding one by another to form
a single stranded polynucleotide chain.
DIFFERENCE BETWEEN DNA AND RNA
TYPES OF RNA
Cells have three major types of RNA
1. Messenger RNA or M-RNA
2. Ribosomal RNA or R- RNA
3. Transfer RNA or T- RNA
m-RNA
CHARACTERS
1. m-RNA transcribed from DNA carrying information for
protein synthesis
2. Comprises only 5% of the cellular RNA
3. Most heterogeneous in size and base sequence
FUNCTIONS
1. All member of the class function as messenger carrying
the information in a gene to the protein synthesizing
machinery.
2. m-RNA carries the genetic information from the nucleus
to the site of protein synthesis in the cytoplasm
r- RNA
CHARACTERS
1. The RNA component of the ribosome
2. It associates with protein to form ribosome
3. r-RNA is essential for protein synthesis in all living
organism
4. Represent 70-80 % of cellular RNA
5. . Found in ribosome & nucleus
FUNCTIONS
1. helps ribosome to bind with m- RNA
2. plays structural and catalytic ( Ribosome) roles in
ribosome
t RNA
CHARACTERS
1. t- RNA molecule consists of single RNA strand that is
only about 80 nucleotide long.
2. Each tRNA molecule has a sequence of three bases called
3.
4.
5.
6.
an anti codons.
Anticodons are complementary to mRNA cordons and
correspond to specific amino acid
t RNA has clover shaped loop structure
Comprises only 50% of the cellular RNA
Small in size
FUNCTIONS
1. Bring amino acid to ribosome during translation
2. Serve physical link between mRNA and amino acid sequence
FUNCTION OF RNA
1. RNA helps in protein synthesis making gene into a trait
2. It takes a copy of DNA molecule out of the nucleus as a
form of mRNA & function as a working copy of DNA
This is the general notes on The Structure and Function of RNA
.
Thank You.