This document provides an overview of molecular biology, including its key components and techniques. It discusses how molecular biology studies biology at the molecular level, focusing on DNA, RNA, and proteins. Some of the key areas and techniques it covers include recombinant DNA technology, genetic engineering, polymerase chain reaction, restriction enzymes, and gel electrophoresis. The document also recognizes several pioneering scientists in the field, such as Watson, Crick, and Morgan, and discusses how molecular biology research has provided major benefits to society.

1. Molecular Biology:
An Era of
Molecules
Dr. Gurpreet Singh, Ph.D (Biotech.)
Assistant Professor,
Department of Biotechnology
Lyallpur Khalsa College, Jalandhar

2. • Brief you about
• Molecular Biology
–Its definition and components
– Recombinant DNA technology
– Genetic engineering

5. Molecular Biology
• …. is the study of the biology at the
molecular level i.e. DNA, RNA and protein.
• The field overlaps with other areas of
biology, particularly genetics and
biochemistry
• Molecular biology concerns with
understanding the interactions between
the various systems of a cell.

7. • Biochemistry
……is the study of molecules at the
function level (e.g. Proteins).
• Genetics
……is the study of the effect of genetic
differences on organisms.

9. Chromosome : the Superstructure

10. All Life depends on 3 critical molecules
 DNAs
Hold information on how cell works
 RNAs
Act to transfer short pieces of information to
different parts of cell
Provide templates to synthesize into protein
 Proteins
Form body’s major components (e.g. hair,
skin, etc.)

11. Central Dogma of Molecular Biology

12. Gene:
• Mendelian definition: a discrete units of hereditary
information located on the chromosomes and
consisting of DNA .
• Molecular Biology: The part of the DNA that encodes
for a functional proteins are called genes. The DNA
consists of 4-nucleotides (A,T,G,C).
Genome:
Sum total of all the genetic material or
genes(DNA) present in the body.
Genomics:
It deals with the systematic use of genome
information to provide answers in biology, medicine, and
industry.

13. Protein
Sequence of amino acids encoded by a gene.
Proteome
The sum total of all the proteins in any organism
Proteomics
A newly emerging field of life science research that
uses High Throughput (HT)technologies to display,
identify and/or characterize all the proteins in a given cell,
tissue or organism (i.e. the proteome).

14. Proteins: Workhorses of the Cell
• 20 different amino acids
– different chemical properties
– cause the protein chains to fold up into specific three-
dimensional structures that define their particular
functions in the cell.
• Proteins do all essential work for the cell
– build cellular structures
– digest nutrients i.e. acts as enzymes
– execute metabolic functions
– Mediate information flow within a cell and among
cellular communities.

15. How Can We Analyze DNA?
……ATGAGCGCCGGAAGCGCGAGTTTCCTCGAGATCCAGCCCTCGGAGCTGGCATTTCCCTTTGAAT
TGATGAAGCAGAGCTCGTGCTCCATGCAACTCGCAAATAAGACCGACCATTATGTAGCATTCAAGG
TCAAAACTACCAACCCAAAGCAGTACTGTGTGCGCCCTAATATTGGCGTTGTACTTCCTGGGTCGA
CTTGTGATGTTACAGTTACAATGCAAGCGCAGAGGGAAGCACCTCCTGATCTGCAGTGTAAGGACA
AGTTCCTAGTTCAAAGTGTTGCAGCTGAGAATGGTGCAGCAACTCAAGATATTAGTGCAGCAATGT
TCAACAAGGAGCCAGGGAAGGTTGTTGATGAATGCAAGCTGCGTGTAATTTATGTGCCAACATCTT
CACCTAGCCTGTTCTCTGAAGATTCAGAACAAGGGAGTTCTGCTCGTTCATTGGAAAACGGGACTC
CTAATTCTACATTGCCACAATCTGTATTTAGATCATCTGGTGAAGCATCAAAGGAGAAGTCCTCGG
AGGCAACATCCATGATTTCCAAGCTAACTGAGGAGAAAATGTCTGCTGTTCAGCAAAACCAGAAGT
TGAGACAAGAGCTGGATGTCCTACGCAAAGAGAGCAGCAAAAGCAACGGCGGTTTCTCAATCACCT
TCTTGATTGTGGTGGGTATTCTGGGCATCATCGCTGGTTTCATCCTCAAGAAGACATAGGAG…………
……….
……MSAGSASFLEIQPSELAFPFELMKQSSCSMQLANKTDHYVAFKVKTTNPKQYCVRPNIGVVLPG
STCDVTVTMQAQREAPTLSAVYGQVPYFQSVAAQNGAATQDISAAMFNKEPGKVVDECKLRVIYVP
TSSPSLFSEDSEQGSSARSLENGTPNSTLPQSVFRSSGEASKEKSSEATSIISKLTEEKMSAVQQN
QKFRQELDVLRKESSKSNGGFSITFL………………….
Protein sequence
DNA sequence

16. Analyzing a Genome
• We analyze a genome in four easy steps.
– Cut it
• Use enzymes to cut the DNA in to small fragments.
– Copy it
• Copy it many times to make it easier to see and detect.
– Read it
• Use special chemical techniques to read the small fragments.
– Assemble it
• Take all the fragments and put them back together. This is hard!!!
• Bioinformatics takes over
– Where we learn from the sequenced DNA about its properties using
computers.

17. Tools in Molecular Biology
• Cutting and joining DNA
– Restriction Enzymes (cutting) and DNA ligase (joining)
• Copying DNA
– Polymerase Chain Reaction (making a million copies in 3 hours)
– Cloning ( copying one gene from an organism to another)
• Measuring DNA Length
– Electrophoresis (separating components exploiting different
properties of the molecule like DNA, RNA and Proteins)
– DNA and protein sequencing

18. Cutting DNA
Restriction Enzymes
Discovered in the early 1970’s
Enzymes from bacteria
Used to cut DNA molecules in specific places

19. Preparing a clone………..

20. Polymerase Chain Reaction (PCR)
 …is a rapid, inexpensive and
simple way of copying specific
DNA fragments from minute
quantities of source DNA
material.
 It does not necessarily require
the use of radioisotopes or toxic
chemicals.
 It involves preparing the sample
DNA and a master mix with
primers, followed by detecting
reaction products.

21. 1. Denaturation: DNA fragments are heated at high
temperatures, which reduce the DNA double helix to
single strands. These strands become accessible to
primers.
2. Annealing: Primers anneal to the complementary
regions in the DNA template strands, and double
strands are formed again between primers and
complementary sequences.
3. Extension: The DNA polymerase synthesize a
complementary strand. The enzyme reads the
opposing strand sequence and extends the primers
by adding nucleotides in the order in which they can
pair. The whole process is repeated over and over.
How PCR works i.e. steps involved

22. Recombinant DNA technology/molecule
Recombinant DNA technology
 the collection of methods used to
accomplish genetic engineering
Genetic engineering
 the deliberate modification of an
organism's genetic information by directly
changing its nucleic acid

23.  Recombinant DNA
 is a molecule that combines DNA from two
sources
 Also known as gene cloning
 Creates a new combination of genetic material e.g.
Human gene for insulin was placed in bacteria
and the bacteria are recombinant organisms and
produce insulin in large quantities for diabetics
 Vector:
molecule carrier of DNA fragment into cell
 Transformation:
uptake of foreign DNA into cells
Some important terms used in
Recombinant DNA Technology

24. Genetic Engineering

25. Blood sample DNA
Restriction enzymes
In a molecular biology lab, we
observe different components as…

26. Gel electrophoresis of DNA, RNA
and Proteins
Electrophoresis is derived from two words
Electro- which means electric field
Phoresis- separation
i.e. Separation of DNA, RNA or the
protein molecule under the influence of
electric field.
Gel
….is a solid support in which the
samples moves and gets separated. It may
be agaroase (DNA or RNA) or
polyacrylamide for protein

27. Some of the Scientist, contribution of whom are
pioneered in the development of the field of Molecular
Biology
Gregor Mendel 1865:
The Father of Genetics
Emil Fischer 1902:
showed amino acids
are linked and form
proteins
Thomas Morgan:
genes on
chromosomes are the
discrete units of
heredity

28. James Watson and Francis
Crick 1953; double helix
structure of DNA
Leroy Hood: Developed
automated sequencing mechanism
• 1995 John Craig Venter: First bacterial
genomes sequenced

31. Major Contribution of the Molecular Biology
studies to the society

33. Thank you for
your kind
attention!!!