Biochemistry of nucleic acids DNA RNA structures with the comparison chart between them chemistry of nucleic acids structures and composition and protein synthesis nucleotides and nucleosides

1. Biochemistry of
Neucleic Acids
Biochemistry presentation
Submitted to: Mam Iqra Baig

2. Nucleic Acids
1. The most important macromolecule
within the organism.
2. Nucleic Acid are polynucleotides that Is
long chain of molecules composed of
series of nearly identical building blocks
called nucleotides.
3. It is essential to all known forms of life.
4. There are two main classes of: DNA and
RNA

3. Continued…
1. Each nucleotide contains bases, pentose
sugar and phosphate group.
2. Bases are Adenine, Guanine, Thymine,
Cytosine and Uracil.
3. Adenine and Guanine form pair and they
are called as purines.
4. Cytosine and Thymine and Uracil (in case
of RNA) are called as pyrimidines.

4. Differences between DNA and RNA
De-oxyribonucleic Acidz
DNA contains de-oxyribose sugar.
 Structure:
DNA is double stranded.
 Reactivity:
DNA is stable under alkaline conditions.
 Bases:
Adenine, Guanine , Cytosine and Thymine.
 Functions:
Its functions are long-term storage of genetic
information, transmission of genetic information to
make other cells and new organisms.
 Base pairing:
• Adenine and Thymine
• . Guanine and Cytosine
Ribonucleic Acid
RNA contains Ribose sugar.
 Structure:
RNA is single stranded.
 Reactivity:
RNA is not stable but it is more reactive than DNA
 Bases:
Adenine, Uracil, Guanine and Cytosine.
 Function:
Its function is used to transfer genetic code from the
nucleus to ribose to make proteins.
 Base pairing:
1.Adenine and Uracil
2. Guanine and Cytosine.

5. Continued…
DNA(De-oxy ribonucleic Acid)
 UV Damage
DNA is susceptible to UV damage.
 Length:
DNA is much longer polymer than RNA.
Example:
Chromosomes are single long
molecule which would be several
centimetres in length.
 Location:
DNA is found in nucleus.
Small amount of DNA is also present in
Mitochondria
RNA (RiboNucleic Acid)
 UV damage:
Compared with DNA, RNA is relatively
resistant to UV damage.
 Length:
RNA molecules are shorter than long
polymers.
A large RNA molecule might only be a
few thousands base pairs
 Location:
RNA forms in the nucleus and thn
moves to specialized regions of
cytoplasm depending on the type of
RNA formed.

6. Interesting Question:
1: Who came first?
DNA or RNA
2:Why DNA evolved if RNA
existed?

7. DNA Double Helix and Hydrogen Bonding:
1. Made of two strands of nucleotides that are joined together by
hydrogen bonding
2. Hydrogen bonding occurs as a result of complimentary base pairing
3. Adenine and thymine pair up
4. Cytosine and guanine pair up
5. Each pair is connected through hydrogen bonding
6. Hydrogen bonding always occurs between one pyrimidine and one
purine

8. DNA Double Helix Structure
1. Adenine always pairs with
thymine because they form
two H bonds with each other
2. Cytosine always pairs with
guanine because they form
three hydrogen bonds with
each other

9. Watson and Crick Model of DNA
• In 1953, James Watson and Francis Crick
proposed the structure of DNA.
• Watson-Crick model of double helical
structure of DNA.
• Adjacent bases are separated by 0.34 nm.
• The diameter or width of the helix is 2
nanometers.

10. • DNA consists of two
polydeoxyribonucleotide chains
twisted around one another in a right
handed double helix.
• The bases are located perpendicular
to the helix axis, whereas the sugars
are nearly at right angles to the axis.

11. • Always the two strands are
complementary to each other. So, the
adenine of one strand will pair with
thymine of the opposite strand, while
guanine will pair with cytosine.
• The base pairing (A with T; G with
C) is called Chargaff’s rule, which
states that the number of purines is
equal to the number of pyrimidines.

12. • The DNA strands are held
together mainly by hydrogen
bonds between the purine and
pyrimidine bases.
• There are two hydrogen bonds
between A and T while there
are three hydrogen bonds
between C and G.
• The GC bond is therefore
stronger than the AT bond.

13. • The two strands in a
DNA molecule run
antiparallel, which
means that one strand
runs in the 5′ to 3′
direction, while the
other is in the 3′ to 5′
direction.

14. • In the DNA, each strand acts as a
template for the synthesis of the
opposite strand during replication
process.
• Within a single turn, 10 base pairs
are seen.
• Thus, adjacent bases are separated
by 0.34 nm.
• The diameter or width of the helix
is 1.9 to 2.0 nm.

15. • RNA stands for ribonucleic acid is a polymeric molecule made up of
one or more nucleotides.
• A strand of RNA cam ne thought of as a chain with a nucleotide at each
chain link.
• Each neuclotide is made up of a base ( adenine, cytosine guanine and
uracil , typically abbreviated as a A,C,G and U ) a ribose sugar and
phosphate DNA and RNA from the fundamental building block of the
universal genetic code.
• They can form complex structure which onteract with protein, other
nucleic acid and even small regulatory molecules RNA can even play a
role as am enzyme ( so called ribozymes) which can directly catalyse
chemical reaction and regulate genetic expression
Introduction

16. • Structure of RNA the
structure of RNA
nucleotides is very similar
to that of DNA nucleotides.
DNA and RNA play very
different roles frompne
another in modern cells
Structure of RNA

18. Structure of RNA
• Structure of RNA Ribonucleic acid
(RNA) is a biolpgically important type
of molecule that consists of a long
chain of nucleotide units. Each
nucleotide consists of a nitrogenous
base, a ribose sugar, and a
phosphate.sugar ribose phosphate
group nitrogen contaonibg base
adenine guanine cytosine uracil

19. Nucleotide
• A nucleotide is an organic molecule that is
building block of DNA and RNA A
nucleotide is made up of three parts a
phosphate group a 5 carbon sugars and a
nitrogen base the four nitrogenous bases in
DNA are adenine , cytosine , guanine , and
thymine RNA contain uracil instead of
thymine , A nucleotide within a chain
makes up the genetic material of all known
living things .

20. Composition of nucleotide
1. A nucleotide is made up of 3 composition
2. A nitrogenous base (a purine and pyrimidine )
3. Pentose sugars either , ribose or deoxyribose
4. Phosphate group esterified to the sugar
5. When a base combine with a pentose sugar a nucleoside is formed.
6. When a second phosphate gets esterified to the existing phosphate
group a nucleoside diphosphate is generated .

21. Bases present in
nucleic Acid
The two types in the
nitrogenous bases;
• Purine
• Pyrimidine
That are presents in nucleic
acid .

22. Purine
1. The purine bases are present in RNA and DNA are the same
Adenine and Guanine.
2. Adenine is 6 amino purine and guanine is 2 amino ,6 oxopurine
.
3. The numbering of the purine ring with the structure of adenine
and guanine.

23. Minor purine Bases
1. These bases may be found in small amounts in nucleic acid and hence
called minor purine
2. These are hypoxanthine 6-Oxopurine and xanthine 2,6-di-Oxopurine.

24. Pyrimidine Bases
1. The pyrimidine bases are present in nucleic acids are
2. Cytosine
3. thymine
4. Uracil

25. Pyrimidine bases
1. Cytosine is present in both DNA and RNA structures are;

26. Pyrimidine Bases
1. Thiamine
2. These are present in DNA and uracil in RNA structers;

27. 1. A few other modified pyrimidine bases like dihydrouracil
and 5-methyl cytokine are also found rarely in some
types of RNA.
Modified pyrimidine Bases

28. Biological importance
1. the nucleotides are important intracellular molecules of low molecular
weight
2. they play an important role in carbohydrate fat and protein metabolism
3. the best role of purine and pyrimidine nucleotides is to serve as the
monomeric precursor of RNA and DNA
4. The purine nucleotide also act as the high-energy fourth ATP cyclic GMP
in a wide variety of tissues and organism and as component of coenzymes
of NAD FAD NADP and of an important Metgyl donor methionine s,
adenosylmethionine
5. the pyrimidine nucleotide also at as a high-energy intermediate such as
udp glucose and udp galactose in carbohydrates metabolism and cDp asyl
glycerol in liquid synthesis.

29. ATp
1. adenosine triphosphate ATP
2. adenosine triphosphate ATP Storage battery of tissues
3. most abundant in cell two of the three phosphate Residue or high
energy phosphate and on hydrolysis each releases energy
4. that utilized for androgenic reaction ATP is an important source of
energy for muscle contraction transmission of nerve impulses transport
of nutrient across the cell membrane mortality of spermatozoa

30. ADp
1. adenosine diphosphate ADP
2. act as a primary po4 acceptor in oxidative phosphorylation the played
an important role in cellular respiration
3. etc. ; and muscle contraction it is also important for activation of the
enzyme glutamate dehydrogenase which is required for the Di
amination reaction is liver to produce ammonia

31. AMp
1. adenosine monophosphate AMP
2. IT Act as an activator of several independent issued in glycolytic
pathway the enzyme is inhibited by ATP but the inhibition is reversed
by AMP
3. AMP is formed by ADP by the enzymes adenylate kinase reaction
4. the AMP produced activate the phosphorylase of enzyme in muscle
and increase the breakdown of glycogen

32. NUCLEOSIDE

33. INRODUCTION OF NUCLEOSIDE ;
• A structural subunit of nucleic acids, the heredity-
controlling components of all living cells, consisting
of a molecule of sugar linked to a nitrogen-containing
organic ring compound. In the most important
nucleosides, the sugar is either ribose or deoxyribose,
and the nitrogen-containing compound is either a
pyrimidine (cytosine, thymine, or uracil) or a purine
(adenine or guanine).
1. Examples of nucleosides
2. Cytidine, uridine, adenosine, guanosine, thymidine
and inosine. While a nucleoside is a nucleobase
linked to a sugar, a nucleotide is composed of a
nucleoside and one or more phosphate groups.

34. TYPES OF NECLEOSIDE
 Adenosine
1. Adenosine is a purine nucleoside that has adenine bound to a ribose sugar by a glycosidic bond.
It is found in all living organisms as a structural component of important biomolecules such as
DNA and RNA. It is also a major molecular component of ATP, ADP, and AMP.
1. Guanosine
1. Guanosine is a purine nucleoside that has guanine bound to a ribose sugar.
It may be converted into nucleotides: guanosine monophosphate cyclic
guanosine monophosphate , guanosine diphosphate or guanosine
triphosphate through phosphorylation
1. Cytidine
1. Cytidine is a pyrimidine nucleoside that has cytosine attached to the
pentose sugar ribose. It may have an antidepressant effect as it could
regulate neuronal-glial glutamate cycling.

35.  Uridine
1. Uridine is a ribonucleoside that has uracil attached to a ribose ring. It is a white,
odorless powder important in carbohydrate metabolism.
 Deoxyguanosine
1. Deoxyguanosine is a purine nucleoside that has guanine attached to a deoxyribose
sugar. Deoxyadenosine differs from guanosine by having deoxyribose as its sugar
component instead of ribose.
 Deoxycytidine
1. Deoxycytidine is a pyrimidine nucleoside that has cytosine attached to a
deoxyribose ring. It differs from cytidine with one oxygen atom removed.
 Inosine
1. Inosine is another nucleoside. One of the ways by which it forms is when
hypoxanthine is attached to a ribose ring via β-N9-glycosidic bond. Inosine can be
found typically in tRNAs. Inosine is also involved in purine nucleotide reactions

36. Medical importance
Nucleoside analogues are produced artificially for use as
therapeutic drugs. They have antiviral properties and
therefore are used to prevent further growth of pathogenic
virus inside the host cell. They may also be used as
anticancer agents.
Nucleosides are important biological molecules that function
as signaling molecules and as precursors to nucleotides
needed for DNA and RNA synthesis. Synthetic nucleoside
analogues are used clinically to treat a range of cancers and
viral infections.

37. THANK YOU !