After isolation of DNA from the source it is digested enzymatically with the help of restriction endonucleases. Enzyme treated DNA is then separated by size in an agarose gel and shifted to a membrane. A radioactive or fluorescently labeled probe is bonded with the DNA on the membrane. They target specific sequences that are marked by the restriction enzyme sites. The size of these fragments varies hence generate a biological bar code of restriction enzyme- digested DNA fragments.
Protein synthesis Introduction Translation or protein synthesis is a central process of central dogma of molecular biology. It deals with production of proteins or chains of amino acids by making use of a mRNA as a template, ribosomes as protein synthesizing machinery and tRNA’s as carriers of amino acids during the translation process Living cells devote about 90 % of their chemical energy to synthesis of proteins and only about 10 % to other biosynthetic processes. More than 35% of the dry weight of the cell consists of ribosomes, proteins involved in translation process and tRNA molecules. This suggests that protein synthesis is an important process for the survival of microorganisms Protein synthesis process in
The term “proteome” or “proteomics” was first introduced in 1995. Proteomics is the characterization and identification of all proteins that expressed by a genome or tissue and understanding how these proteins function (Mohanty, 2005). Besides, the purpose of proteomics is not only to recognize all the proteins in a cell but also to generate a complete three-dimensional (3D) map of the cell indicating where the proteins are located. To achieve these goals require the involvement of a large number of different fields such as biochemistry, molecular biology and bioinformatics. Many different areas of study are now grouped under the proteomic such as sequence and structural proteomics, expression proteomics, interaction proteomics and functional
DNA also can directly repaired damaged bases. A repair enzyme recognizes incorrect structure in the DNA and directly converts it to a correct structure. Base exision repair involves a category of enzymes known as DNA-N-glycosylacases. The enzymes identify the damaged base and cleave the bond between it and the sugar in the DNA. Then it will remove one base, excises several around it and then replaces it with several new bases using DNA polymerase adding to 3’ ends and then closing it with ligase attached to 5’ end.
Background Questions P. 2 #1: What is the purpose of electrophoresis?  The purpose of electrophoresis is to separate charged biomolecules such as DNA, RNA, and proteins through differences in the their characteristic such as shape, size, and charge. P. 2 #1: On what basis does agarose gel electrophoresis separate molecules?  Agarose gel electrophoresis separates molecules based on their size, shape, and charge. Within the gel exist pores which the molecules must move through in order to reach the positively or negatively charged electrode.
Homologous recombination (HR) can be explained as a process where DNA is exchanged or copied between two chromosomes or different regions of the same chromosome. The process requires homology between the exchanging DNA regions. Homologous recombination repairs DNA breaks, especially double stranded breaks (DSBs), stabilizes and repairs stalled forks. HR consists of a series of inter related pathways that function in repair of DNA breaks (Figure 4). Initially, stretches of single stranded DNA (ssDNA) are resected at the stalled forks or DSB ends which are quickly bound by replication protein A (RPA).
Student’s Name Professor’s Name Subject DD Month YYYY Question Answer Question 1: Section (a): Composition of Nucleosomes The nucleosome is the basic unit of the DNA and forms the building block of chromatin. Chromatin is a complex of the DNA and the cellular histone protein cores forming eukaryotic chromosomes. Structurally, the nucleosome core particle comprises 1.6 left-handed superhelical turns of DNA wound around a protein complex called the histone octamer, which consists of 2 copies each of the core histones attached to the central tetramer H3/H4. The latter is flanked by two H2A/H2B dimers (Kornberg 868). The histone octamer, therefore, is a set of the 8 basic proteins whose fundamental structure of a single molecule includes three
This breaks the DNA loop. The two AraC-arabinose complexes bind to the aral1 and aral2 sites which promotes transcription. When arabinose is present, AraC acts as an activator. If arabinose is present, it builds a complex: AraC + arabinose This complex is needed for RNA polymerase to bind to the promoter and transcribe the ara operon. Also for activation the binding of another structure to aral is needed: CRP+cyclic AMP so the activation depends on the presence of arabinose and cAMP.