BIOL 130 Lecture Notes - Lecture 19: Enterobacteria Phage T2, Radionuclide, X-Ray Crystallography
Document Summary
Genes exist as parts of chromosomes chromosomes are made of: dna, proteins transformation- change in genotype and phenotype due to assimilation of external dna by a cell, ex- dead pathogens mixed with non-pathogens= living pathogens. Virus- little more than just dna enclosed by a protective coat made of protein. Virus reproduces by infecting a cell and taking over its metabolic machinery. T2 phage- composed almost entirely of dna and protein: could turn e. coli into a t2 producing factory, t2 could reprogram its host cell to produce more viruses (which component of. Dna- made of phosphate group, sugar, 1 of 4 nitrogenous bases. Chargaff"s rules: the base composition of dna varies between species, for each species, a and t are nearly equal and c and g are nearly equal. X-ray crystallography- used to determine structure of dna. Suggested width and of helix and spacing of nitrogenous bases: helix was made up of two strands not three.
