What is Molecular Biology?

• lReally an in-depth study of “life technology”

• lInvolves complex chemical interactions of 1000’s of different types of molecules found in any cell!

• lHow is it organized? DNA is the “Master Molecule”:  Structure of DNA à information to create / direct the chemical machinery of life

• lWhat is “Molecular Genetics”? The study of the flow and regulation of the genetic information of DNA / RNA 

 

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 Molecular Biology is a Hybrid Discipline, drawing upon many areas of expertise:

• ·Physics – energy changes and supporting math

• ·Physical Chemistry – the many reactions

• ·Microbiology – observation of single cells

• ·Biochemistry – biochemical components and reactions

• ·Genetics – the information behind life

 

Early History:

lStarted with observation of structure of living organisms, but nlow examines the DNA / information controlling living systems. A quick snapshot of the early history of molecular biology is provided below:

• l1859 – Darwin – looks at changes in population

• l1865 – Mendel – traits inherited by individual organisms

• l1902 – Sutton – chromosome behaviour in cells

• l1941 – Beadle and Tatum – biochemical interactions in cells

• l1944 – Hershey and Chase – DNA interactions in cells

• l1953 – Watson and Crick – molecular structure of DNA

• l1956 - DNA is made artificially.

• l1969 - The first single gene is isolated.

• l1970 - The first artificial gene is made.

• l1973 - Genetic engineering begins with the ability to insert genetic material.

• l1976 - An artificial gene is inserted into a bacterium and, for the first time, works normally.

• l1978 - Bacteria are engineered to produce insulin.

• l1981 - A gene is transferred from one animal species to another.

• l1984 - genetic fingerprinting developed.

• l1984 - gene experiment to try to treat a 4-yr-old girl.

• l1993 - Mice are cured of cystic fibrosis via gene therapy.

• l2001 - The first draft of the human genome published.

 

History - Darwin

1. 1.“Natural Selection” (over huge periods of time) selects for the “fittest” version of the life form
2. 2.Arises as organisms “best able to feed, survive and mate”à have offspring with strong characteristics
3. 3.Occasionally  get “random” physical changes that really help
4. 4.Winning / fittest characteristics continue in offspring

 

History - Mendel (Austrian Monk)

1. lSought to explain how “winning” traits passed between generations
2. lHe related outward appearance (phenotype) to genetic makeup (genotype)
3. lDetermined Dominant and Recessive genes
4. lEach parental cell has only one type
5. lCombination of parental info is random! (Cc x Pp à CP  cP  Cp  cp  (four combos)

   

 

History - Watson and Crick

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• l

  DNA is made of 2 anti-parallel chains in a right-handed double helix

• lComplementary base pairs form hydrogen bonds across duplex A=T, C≡G

• lThere are ~ 10 b.p. / each complete turn of the double helix

 

Each of the above scientists and many. many more have contributed to what is now termed "Molecular Biology". The following sections will examine the various areas of Molecular Biology as we see it today.

 

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