Introduction to Molecular BiologyFirst Lecture

Gihan E-H Gawish, MSc, PhDAss. Professor

Molecular Genetics and Clinical Biochemistry

KSU

Molecular BiologyWhat is the molecular biology science? And

Why it is important to study?!

Timeline Events of Molecular Biology:

• 1860 Mendel – Mendel’s law of inheritance, gene& chromosome

• 1868 Miescher – nuclein, contained an acidic material

• 1890 Weismann - substance in the cell nuclei controls development.

• 1900 Chromosomes shown to contain hereditary information, later shown to be composed of protein & nucleic acids.

• 1928 Griffith’s Transformation Experiment

• 1944 Avery’s Transformation Experiment

• 1953 Hershey-Chase Bacteriophage Experiment

• 1953 Watson & Crick propose double-helix model of DNA

• 1956 Gierer & Schramm/Fraenkel-Conrat & SingerDemonstrate RNA is viral genetic material.

The law of independent assortment

The law of independent segregation

The law of dominance

1 -Mendel’s Three Law of Inheritance:// . . / / /http www sumanasinc com webcontent animations c

/ / .ontent mendel mendel html

Comment: Genes are located on chromosomes

Called in nuclein since it was from the nucleus

Had large amounts of phosphorous and no sulfur so was very different than protein

2 -Friedrick Miescher, a Swiss chemist

(Discovery of Deoxyribonucleic acid)

Comment: the two constituents of chromosomes; Proteins & DNA

Analytical Tests forC, H,P,O and N

“Nuclein”

DNA the molecule of life