Molecular BiologyMolecular BiologyPrinciples and Basic ToolsPrinciples and Basic Tools

Molecular Biology - DefinitionMolecular Biology - Definition

Molecular biologyMolecular biology is the study of biology at a is the study of biology at a molecular level. molecular level.

Molecular biologyMolecular biology; the study of ; the study of genegene structure and structure and functions at the functions at the molecular levelmolecular level to understand the to understand the molecular basis of hereditarymolecular basis of hereditary, , genetic variation, genetic variation, and the expression patterns of genesand the expression patterns of genes..

The field overlaps with other areas of biology and The field overlaps with other areas of biology and chemistry, particularly genetics and biochemistry.chemistry, particularly genetics and biochemistry.

Molecular Biology Interdisciplinary Molecular Biology Interdisciplinary ScienceScience

Molecular biology chiefly concerns itself Molecular biology chiefly concerns itself with understanding the interactions with understanding the interactions between the various systems of a cell, between the various systems of a cell, including the interactions between DNA, including the interactions between DNA, RNA and protein biosynthesis as well as RNA and protein biosynthesis as well as learning how these interactions are learning how these interactions are regulated regulated

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Beginning of Molecular BiologyBeginning of Molecular Biology

The The Modern of molecular biologyModern of molecular biology begins in begins in the 1930s with the convergence of various, the 1930s with the convergence of various, previously distinct biological disciplines: previously distinct biological disciplines: biochemistry, genetics, microbiology, and biochemistry, genetics, microbiology, and virology.virology. With the hope of understanding life at With the hope of understanding life at its most fundamental level, numerous physicists its most fundamental level, numerous physicists and chemists also took an interest in what would and chemists also took an interest in what would become molecular biology. become molecular biology.

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Warren WeaverWarren Weaver While molecular biology While molecular biology

was established in the was established in the 1930s, the term was first 1930s, the term was first coined by coined by Warren Warren WeaverWeaver in 1938. Warren in 1938. Warren was the director of was the director of Natural Sciences for the Natural Sciences for the Rockefeller Rockefeller FoundationFoundation.. ..

Size of Human GenomeSize of Human Genome Each cell carries: 3.2 billion base pairsEach cell carries: 3.2 billion base pairs Approximation:Approximation: 500 books, each book of 500 pages500 books, each book of 500 pages All cell in an adult contain DNA whch can All cell in an adult contain DNA whch can

run 70 times from sun to earth and backrun 70 times from sun to earth and back(length of 1 bp)(number of bp per cell)(number of cells in the body)(length of 1 bp)(number of bp per cell)(number of cells in the body)

(0.34 × 10(0.34 × 10-9-9 m)(6 × 10 m)(6 × 1099)(10)(101313))

2.0 × 102.0 × 101313 meters meters

That is the equivalent of nearly 70 trips from the earth to the sun and back.That is the equivalent of nearly 70 trips from the earth to the sun and back.

2.0 × 102.0 × 101313 meters = 133.691627 astronomical units meters = 133.691627 astronomical units133.691627 / 2 = 66.8458135 round trips to the sun133.691627 / 2 = 66.8458135 round trips to the sun

Watson and CrickWatson and Crick

The structure of The structure of DNADNA was described by was described by British Scientists British Scientists Watson andWatson and CrickCrick as long as long double helix shaped with its sugar double helix shaped with its sugar phosphate backbone on the outside and its phosphate backbone on the outside and its bases on inside; the two strand of helix run bases on inside; the two strand of helix run in opposite direction and are anti-parallel to in opposite direction and are anti-parallel to each other. The each other. The DNADNA double helix is double helix is stabilized by hydrogen bonds between the stabilized by hydrogen bonds between the basesbases

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Watson and Crick discovers DNA / Watson and Crick discovers DNA / Feb 28Feb 28thth 1953 1953

Watson and Crick Builds a Model Watson and Crick Builds a Model DNA 7DNA 7thth March 1953 March 1953

First Document on DNA published First Document on DNA published in Nature 25in Nature 25thth April 1953 April 1953

Watson and Crick - Awarded Nobel Prize in Watson and Crick - Awarded Nobel Prize in 19621962

DNA - StructureDNA - Structure The nucleotide, however, The nucleotide, however,

remains as the fundamental remains as the fundamental unit (monomer) of the unit (monomer) of the nucleic acid polymer. nucleic acid polymer. There are four nucleotides: There are four nucleotides: those with cytosine (C), those with cytosine (C), those with guanine (G), those with guanine (G), those with adenine (A), those with adenine (A), and those with thymine and those with thymine (T). (T).

DNADNAA purine always links with a A purine always links with a

pyrimidine base to pyrimidine base to maintain the structure of maintain the structure of DNADNA..

Adenine ( A ) binds to Thymine Adenine ( A ) binds to Thymine ( T ), with two hydrogen ( T ), with two hydrogen bonds between them.bonds between them.

Guanine ( G ) binds to Cytosine Guanine ( G ) binds to Cytosine ( C ), with ( C ), with three hydrogen three hydrogen bondsbonds between them between them..

Building Blocks of DNABuilding Blocks of DNA

Chemical structure of Chemical structure of DNADNA

DNA is Endless structureDNA is Endless structure The rungs of the ladder The rungs of the ladder

can occur in any order can occur in any order (as long as the base-pair (as long as the base-pair rule is followed) rule is followed)

Those 4 bases have Those 4 bases have endless combinations endless combinations just like the letters of the just like the letters of the alphabet can combine to alphabet can combine to make different words. make different words.