Plasmid Isolation (Alkaline Lysis)

Bacterial plasmids, the non-genomic transferable DNA, can easily be purified from bacteria using numerous techniques.  The purification of DNA is important for genetic research as it provides a source of transferable DNA and allows researchers to isolate large amounts of recombinant DNA. One common technique for plasmid purification is the alkaline lysis method, which breaks open bacteria with an alkaline solution, proteins are removed by precipitation and the plasmid DNA is recovered with alcohol precipitation.
Students purify bacterial plasmids from a liquid culture using this alkaline lysis method. 

Protein biosynthesis

Protein biosynthesis (Synthesis) is the process in which cells build proteins. The term is sometimes used to refer only to protein translation but more often it refers to a multi-step process, beginning with amino acid synthesis and transcription which are then used for translation.

Protein biosynthesis, although very similar, differs between prokaryotes and eukaryotes.The events following biosynthesis include post-translational modification and protein folding. During and after synthesis, polypeptide chains often fold to assume, so called, native secondary and tertiary structures. This is known as protein folding. Amino acids are the monomers which are polymerized to produce proteins.

Amino acid synthesis is the set of biochemical processes (metabolic pathways) which build the amino acids from carbon sources like glucose. Not all amino acids may be synthesised by every organism, for example adult humans have to obtain 8 of the 20 amino acids from their diet. The amino acids are then loaded onto tRNA molecules for use in the process of translation.

RNA

Ribonucleic acid or RNA is a nucleic acid polymer consisting of nucleotide monomers that plays several important roles in the processes that translate genetic information from deoxyribonucleic acid (DNA) into protein products; RNA acts as a messenger between DNA and the protein synthesis complexes known as ribosomes, forms vital portions of ribosomes, and acts as an essential carrier molecule for amino acids to be used in protein synthesis. RNA is very similar to DNA, but differs in a few important structural details: RNA is single stranded, while DNA is double stranded.

Also, RNA nucleotides contain ribose sugars while DNA contains deoxyribose and RNA uses predominantly uracil instead of thymine present in DNA. RNA is transcribed from DNA by enzymes called RNA polymerases and further processed by other enzymes.

RNA serves as the template for translation of genes into proteins, transferring amino acids to the ribosome to form proteins, and also translating the transcript into proteins. RNA is a polymer with a ribose and phosphate backbone and four different bases: adenine, guanine, cytosine, and uracil.
The first three are the same as those found in DNA, but in RNA thymine is replaced by uracil as the base complementary to adenine. This base is also a pyrimidine and is very similar to thymine.

Uracil is energetically less expensive to produce than thymine, which may account for its use in RNA. In DNA, however, uracil is readily produced by chemical degradation of cytosine, so having thymine as the normal base makes detection and repair of such incipient mutations more efficient. Thus, uracil is appropriate for RNA, where quantity is important but lifespan is not, whereas thymine is appropriate for DNA where maintaining sequence with high fidelity is more critical.