[1S] UNIT 1.2 History of Molecular Biology Flashcards
ORIGINS OF MOLECULAR BIOLOGY
T/F: Arose from the convergence of work by geneticists, physicists and structural chemists on the nature of inheritance.
T
ORIGINS OF MOLECULAR BIOLOGY
T/F: Molecular diagnostics is relatively a young science tracing back from the 1930s to 1940s and becoming institutionalized on the 1950s and 1960s.
F; Molecular biology
The study of biomolecules and biomolecular mechanisms that occur in living organisms.
Molecular Biology
Mainly focused on the structure and function of gene: molecular nature of the gene, gene replication, mutation and repair and gene expression
Molecular Biology
The study of molecular basis of life such as biochemical processes that control information flow through biochemical signalling and the flow of chemical energy through metabolism.
Biochemistry
Deals with the structures and functions of cellular components such as proteins, carbohydrates, lipids and nucleic acids.
Biochemistry
T/F: Molecular biology and biochemistry are closely related disciplines. Initially, biochemistry focuses on proteins and enzymes until it includes nucleic acids and the molecular mechanisms by which genetic information from DNA results in the processes of life.
T
The term “molecular biology” was coined by _______ ______ of the Rockefeller Foundation in 1938 – in recognition of the importance of new physical and structural chemical approaches to biology.
Warren Weaver
_______ _______ work on transmission of inheritable traits – Law of Aggregation & Law of Independent Assortment
Gregor Mendel
Father of Modern Genetics
Gregor Mendel
Discovered “nuclein” a new molecule from the cell nucleus and believed that proteins were the molecules of heredity, in 1869.
Friedrich Miescher
previously thought the transforming principle is now called the DNA.
Nuclein
In 1928, ________ ________ was studying two strains of Streptococcus pneumoniae that varied dramatically in both their appearance and their virulence. Specifically, the highly virulent S strain had a smooth capsule (polysaccharide), while the nonvirulent R strain lacked a capsule.
Frederick Griffith
found that mice inoculated with either the heat-killed virulent bacteria or the living avirulent bacteria remained free of infection, but mice inoculated with a mixture of both became infected and died.
TRANSFORMING PRINCIPLE: Frederick Griffith
hypothesized that a chemical component from the virulent S cells had somehow transformed the R cells into the more virulent S form
TRANSFORMING PRINCIPLE: Frederick Griffith
In 1944, ________, _______, _______ used a process of elimination to identify the transforming principle.
Oswald Avery, Colin McLeod and Maclyn McCarty
T/F: According to Griffith, DNA is the hereditary material. Thus, transformation cannot occur unless DNA is present.
F; Oswald Avery, Colin McLeod and Maclyn McCarty
DNA AS THE GENETIC MATERIAL
In 1952, they prove that DNA is the transforming principle and not protein using series of experiments involving T2 bacteriophages.
Alfred Hershey and Martha Chase
DNA AS THE GENETIC MATERIAL
are viruses that infect bacteria (T2 bacteriophage infects E. coli) and widely used for studying genetic transmission.
Bacteriophages
DNA AS THE GENETIC MATERIAL
Consists both of protein and DNA which can be selectively incorporated by radioactive isotopes for tracing of bacterial infection. (32-phosphate for DNA and 35-sulfur for protein).
T2 bacteriophage
The elucidation of the double helical nature of DNA must be attributed to the contributions of key scientists (______, _______, ______) including the X-ray crystallography done by _______ ________ & _________ _______.
Miescher, Levene and Chargaff
Rosalind Franklin and Raymond Gosling
Discover the order of the three major components of a single nucleotide (phosphate-sugar-base), carbohydrate component of RNA (ribose), carbohydrate component of DNA (deoxyribose)
Phoebus Levene
first to correctly identify the way RNA and DNA molecules are put together
Phoebus Levene
● the nucleotide composition of DNA varies among species
● almost all DNA-no matter what organism or tissue type it comes from maintains certain properties even composition varies (“Chargaff Rules”)
● In particular: A = T; C = G (A + G) = (C + T)
Erwin Chargaff