(1) RNA occurs in nucleoli, chromosomes, and cytoplasm, with about 90% found in the cytoplasm. (2) There are three main types of RNA - messenger RNA (mRNA) which carries DNA information, transfer RNA (tRNA) which works as an adaptor to carry amino acids during protein synthesis, and ribosomal RNA (rRNA) which is associated with ribosomes. (3) The key differences between RNA and DNA are that RNA contains the sugar ribose instead of deoxyribose, replaces thymine with uracil, and is a single-stranded molecule.

1. RNA 1
Name:
Muhammad BinNaseem
RollNumber:
F16-0358
Section:
A
Department:
Department ofAgricultural Sciences
University:
UniversityofHaripur
Email:

2. RNA 2
muhammadbinnaseem@gmail.com
SubmittedTo:-
RasheedAkber
RNA
RNA occurs in Nucleoli, chromosomes and cytoplasm (about 90% of the
cells RNA occurs in the cytoplasm). RNA chemically consists of 5 carbon
ribose sugar. RNA is single stranded molecule/ RNA is chemical messenger
and plays a key role in the process of Protein synthesis,
RNA consists of sugars, bases and Phosphoric acid. Sugar is ribose against
Deoxyribose in DNA. In RNA the bases are adenine, guanine, uracil and
cytosine i.e. they mine of DNA is replaced by uracil.
Types of RNA
Various types of RNA are found in plant cells.
(a) Messenger RNA (mRNA)
Which carries the information contained in DNA
(b) Transfer RNA (t RNA)
Also known as soluble RNA which work as adaptor molecules for
carrying amino acids to the site of Protein synthesis
(c) Ribosomal RNA (r RNA)

3. RNA 3
Which is associated with ribosome. All these three types are
monogenetic RNA.
Messenger RNA (mRNA)
Comprises only 5% of the RNA in the cell
Most heterogeneous in size and base sequence
All members of the class function as messengers carrying the information in
a gene to the protein synthesizing machinery
Transfer RNA (t RNA)
Transfer RNA are the smallest of three major species of RNA molecules
They have 74-95 nucleotide residues
They are synthesized by the nuclear processing of a precursor molecule
They transfer the amino acids from cytoplasm to the protein synthesizing
machinery, hence the name t RNA.
They are easilysoluble, hence called“Soluble RNA or s RNA
They are also called Adapter molecules, since they act as adapters for the
translation of the sequence of nucleotides of the m RNA in to specific amino
acids
There are at least 20 species of t RNA one corresponding to each of the 20
amino acids required for protein synthesis

4. RNA 4
Ribosomal RNA (r RNA)
The mammalian ribosome contains two major nucleoprotein subunits—a
larger one with a molecular weight of 2.8 x 106 (60S) and a smaller subunit
with a molecular weight of 1.4 x 106 (40S).
The 60S subunit contains a 5S ribosomal RNA (r RNA), a 5.8S r RNA, and a
28S r RNA; there are also probably more than 50 specific polypeptides.
The 40S subunit is smaller and contains a single 18S r RNA and
approximately 30 distinct polypeptide chains.
All of the ribosomal RNA molecules except the 5S r RNA are processed from
a single 45S precursor RNA molecule in the nucleolus.
5S r RNA is independently transcribed.
Differences between DNA and RNA
DNA
 Sugar moiety is deoxyribose
 Uracil is absent.
 Double stranded molecules.
 Sum of purine bases is equal to sum of pyrimidine base.
(A+G)=(C+T)
 Resistant to hydrolysis by alkali because of absence of hydroxyl
group on 2 carbon atom of deoxyribose.
RNA
 Sugar moiety is ribose.
 Thymine is absent.
 Single stranded molecules.
 Sum of purine bases is not equal to sum of pyrimidine base.
(A+G)#(C+T)
 Because of presence of hydroxyl group on 2 carbon atom of ribose,
RNA is easily hydrolyzed by alkali.

5. RNA 5