Lab #6 info

Lab #6 info - Laboratory VI You are working with E. coli...

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Laboratory VI You are working with E. coli bacterial strain Make sure your lab coats are buttoned You must use gloves (lab 6-10) when you have cuts and bruises on your hands Limit the paper material at the work area to avoid contamination Wash your hands well with soap before you leave the lab Topic: Bacterial Transformation Introduction : Genes are short segments of DNA and located in the chromosomal DNA. In bacteria, genes are also present on extrachromosomal DNA, known as plasmids. The primary transfer of genetic information within cells follows the order: DNA→RNA→PROTEIN→TRAIT. DNA is deoxyribonucleic acid and is the universal template for biological information. DNA molecules are very long chains composed of repeating subunits known as nucleotides or bases A , G , C , and T . DNA almost always occurs in double-stranded form, the two strands containing complementary. (i) A pairs with T (ii) C pairs with G. The double-stranded pair is written as follows: 5'. .. AGGTC ...3' 3'. .. TCCAG ...5' The process of copying segments of DNA into RNA is called transcription , and is performed by a protein called RNA polymerase . RNA is ribonucleic acid and helps to retrieve and execute the instructions which are stored in DNA. The pairing rules are the same as for DNA except that A pairs with U . Some examples of RNA are mRNA, tRNA and ribosomal RNA. Although RNA can pair with complementary RNA or DNA, in cells RNA is usually single-stranded. RNA molecules are generally short, compared to DNA molecules; this is because each RNA is itself a copy of a short segment ( gene coding regions) from a DNA molecule. The information residing in RNA is used to assemble the amino acids in proteins. Ribosomes read mRNA sequences by a process called “ translation” to synthesize amino acids. During translation, the ribosome reads 3 nucleotides at a time known as a codon. There are 64 possible codons. Each codon is assigned to an amino acid ( Glycine - GGT, GGC, GGA, GGG; Lysine : AAA, AAG) or a start (ATG) or stop signal (TGA). Proteins perform biochemical functions inside (and often outside) the cell. Enzymes act as catalysts in chemical reactions; Hormones carry signals from one part of a cell to another or from one cell to another; Regulatory proteins police various activities within cells so as to keep them within “legal” limits. The precise three-dimensional features of the protein structure determine its function. The exact sequence of amino acids within a polypeptide chain determines how that chain will fold into its three-dimensional structure. Proteins determine the trait or phenotype. Trait is the feature observed in the organism. Examples: disease trait, pigmentation, antibiotic resistance. Recombinant DNA Technology
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This note was uploaded on 03/09/2011 for the course PHS 2301 taught by Professor Bohu during the Spring '11 term at St. John's.

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Lab #6 info - Laboratory VI You are working with E. coli...

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