Share
Explore BrainMass

Reading the Genome and Gene Expression

The genome is comprised of chromosomes which contain DNA, the molecule essential for producing proteins and thus, expressing genes. In order to read the genome and express genes, DNA must create RNA which then is utilized to synthesize proteins.

Protein production requires two important processes, these are transcription and translation. In a nutshell, transcription is a process in which the DNA double helix becomes unwound and gets translated into mRNA within the cell nucleus. This mRNA then undergoes splicing and receives a 5’ cap and a 3’ tail so that it is able to leave the nucleus and safely enter the cytoplasm so that this mRNA can be read. Splicing is necessary so that only the appropriate DNA is encoded and the 5’ cap and 3’ tail are needed to protect the mRNA which must travel in the cytoplasm.

The process of translation is required to actually synthesize the protein. Translation is done using ribosomes found in the cytoplasm. These ribosomes read the mRNA and attach the complementary tRNA molecules which carry the appropriate amino acids. A series of amino acids joined together make up a polypeptide and proteins are composed of polypeptides.

It is through gene expression and the controls inflicted upon gene expression that the cells within an organism become differentiated, creating the different phenotypes which exist. Genes are controlled through different methods such as developmental programs and variations in promoter sequences for instance.

Furthermore, in terms of gene expression, certain processes such as post-transcriptional processes and post-translational modification alter the function of particular proteins. Other factors, for example, the fact that some genes are only expressed in certain tissues, also greatly influence gene expression and organism differentiation.

Evidently, the genome and gene expression are two incredibly related concepts. Understanding these concepts is instrumental to the study of genetics and analyzing the uniqueness of all species which exist. 

Genetics-From genes to protein, mutations.

Transcribe and translate EACH of the three following DNA gene sequences. Turn these in using the graphic organizer. The letters represent the DNA N-base sequences of the genes. The first is the original gene. The next two are mutations of the original. Note that the changes (mutations) are shown in parenthesis. Original Ge

Gene Regulation and Expression

Diphtheria is caused by strains of Corynebacterium diphtheriae that are lysogenic for a bacteriophage called "b". This phage carries a gene for an endotoxin (tox) that inhibits eukaryotic protein synthesis, and is a major virulence factor for this pathogen. Gene order in the b prophage is shown below: C. diphtheriae that ar

Ancient DNA

1. What are two of the major challenges associated with studying ancient DNA? 2. Provide two key insights into the evolutionary history of Neandertals that have been derived from the analysis of mitochondrial DNA (mtDNA). In what ways might the use of mtDNA be misleading or limiting? 3. Who were the Denisovans? From an ant

Reading Scientific Research Papers

I am reading up on a research paper. Can someone explain how using a luciferase reporter gene by being positioned next to the PPRE-containing fatty acyl CoA oxidase gene promoter? Was used to assess the effect of X protein since it was not in the knockout mice? I would appreciate it if it is short and simple so I can understand

Calculating the number of replication units in Drosophila genome

DNA (3.5 x 108 base pairs) in diploid cells of Drosophila melanogaster is replicated in about 3 minutes. Assuming that all replication forks move at a constant rate of 104 base pairs per minute, what is the minimum number of replication units present in the Drosophila genome?

lambda phage genome insertion

Integration of the lambda phage genome into the E. Coli chromosome involves: A Staggered cleavage of viral DNA, formation of a blunt-ended double strand break in the bacterial DNA, joining of the ends of the two DNA molecules, gap filling by DNA polymerase, and ligation of the last phosphodiester bond. B Staggered cleavage of

Operon overview

What are the components of an operon? What important regulator is not part of the actual operon? Know how operons are classified and how each type works (Inducible, Repressible, Positive, Negative.)

Two functions of DNA

Word paper that describes two functions of DNA and explains how DNA's structure allows it to fulfill these functions. Include the following in your answer: o Structure of a nucleotide o Base-pair rules o Process of replication, including enzyme function o RNA structure o Process of transcription o Translation o Codons a

CDNA libraries and RNA editing

(i) When constructing cDNA libraries it is very important to copy the whole of an mRNA into cDNA. One way to try and ensure that the 5' end of a mRNA is represented in a cDNA copy is to use "cap-trapper" technology. Explain in your own words and with a simple diagram how this works (do not include other steps in cDNA library c

DNA

1. Describe DNA sequencing with reference to the cloning of a DNA fragment in a bacteriophage M13 based cloning vector. 2. Describe the use of a expression vector to isolate the gene from a cDNA library that codes for a specific protein.

Mutations affecting the function of lac operon

Mutations can alter the function of an operon. Predict how the following mutations would affect the function of the lac operon in the presence and absence of allolactose (lactose). Please indicate if transcription will occur or if transcription will not occur. If this result is the same as what would have occured without the

Mutation rates are assessed.

The mutation rate to a lethal, recessive genetic illness is 10-10. Individuals die before they get a chance to reproduce. Under mutation-selection balance, what is the equilibrium frequency of the recessive allele? What is the equilibrium frequency of the genetic illness?

Human Genome

How did human populations adapt to alcohol consumption and how did they adapt to milk consumption in adult life?