Draft 1
What is Genomics?
Thesis statement: Genomics is the study of genomes. A genome is the entire DNA code found in the chromosomal set of an organism. A comprehensive genome study would include three parts: (1) structural genomics, (2) functional genomics, and (3) comparative genomics.
Topic Sentence 1: To begin the study of a genome, the first examination is structural analysis of the genome. A structural analysis refers to the location of each gene on a given DNA sequence. Structural analysis is done by molecular and computing techniques which include sequencing and assembly respectively. Today, there is several sequencing techniques used for the study of a genome. The first technique that was used is the Sanger method. Sanger sequencing method is a chain termination reaction that involves the synthesis of DNA strands that are complementary to a single- stranded DNA template (1). The end product of sequencing by the Sanger method is short segmented fragments of DNA. To form the whole genome sequence, the DNA fragments are arranged back together, forming a long continuous sequence of DNA, in short terms, sequence assembly. The ultimate goal of structural genomics is to identify every gene in the genome sequence. Sequence inspection can be used to locate genes because genes are not random series of nucleotides (structural unit of DNA and RNA) but instead have distinctive features. For example, genes always start with a specific sequence, the initiation codon (ATG). This codon (a three-nucleotide sequence that codes for one amino acid) codes for the amino acid methionine (Met).
Topic Sentence 1: To begin the study of a genome, the first examination is structural analysis of the genome. A structural analysis refers to the location of each gene on a given DNA sequence. Structural analysis is done by molecular and computing techniques which include sequencing and assembly respectively. Today, there is several sequencing techniques used for the study of a genome. The first technique that was used is the Sanger method. Sanger sequencing method is a chain termination reaction that involves the synthesis of DNA strands that are complementary to a single- stranded DNA template (1). The end product of sequencing by the Sanger method is short segmented fragments of DNA. To form the whole genome sequence, the DNA fragments are arranged back together, forming a long continuous sequence of DNA, in short terms, sequence assembly. The ultimate goal of structural genomics is to identify every gene in the genome sequence. Sequence inspection can be used to locate genes because genes are not random series of nucleotides (structural unit of DNA and RNA) but instead have distinctive features. For example, genes always start with a specific sequence, the initiation codon (ATG). This codon (a three-nucleotide sequence that codes for one amino acid) codes for the amino acid methionine (Met).
The issue is complicated, because genes are not continuous, and are interrupted by the non-coding sequences called introns. However, these elements can also be identified, because they have common features. Finally, gene sequences always end with a termination codon (for example: UGA). Termination codon interrupts the process of transcription (copying of DNA into RNA), and thus always ends a gene. The sequence identified in this manner between initiation and termination codon is called an open reading frame (ORF). Once all the genes have been located, a complete structure of the genome has been completed.
Topic Sentence 2: As part of a genome study, it is required to narrow down the study and focus in a chromosome and the genes that it contains. By doing this it is easier to find the functions of the genes. Functional genomics is the part of genome study where the functions of genes are determined. As the genes regularly have many different functions, this task is often difficult. Functional genomics is also concerned with interactions between genes and functional differences between different variants of the same gene, as in cancer studies.
function
Topic Sentence 3: Comparative genomics is the part of that compares genomes of related species and determines how they differ in structure and function. This part of genomics is concerned with evolutionary processes, which is how did genomes acquire their present characteristics. And one of the most important questions it studies is “what makes us human”?
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