Lac operon

1. What are proinsulin and insulin? How different is proinsulin from insulin? A: Insulin is a polypeptide hormone, protein, that is produced by the beta-cells of the pancreas. Proinsulin is a single peptide chain that is a precursor to insulin. It is produced by the beta-cells of the pancreas as well. The structure of proinsulin differs from insulin in that it contains a C-chain that forms a single peptide chain with other chains A and B. Insulin does not contain the C-chain and the A and B…

1) Alcaligenes faecalis is a Gram-negative coccobacilli that is motile, oxidase positive, catalase positive, non-spore-forming, non-fermenting, slow growing, and citrate positive obligate aerobe (Mahon et al., 2014) (Sachdeva et al., 1963). Its colony morphology is flat, thin, and rough with irregular edging (Mahon et al., 2014) and the flagella varies between the usual shape versus the curly structure, however, both shapes do not exist on the same individual bacteria (Leifson, 1960). The…

Illustration of sexduction in E. coli using streptomycin resistant F-lac- recipients and F′lac+ donors Abstract The process in which DNA from a donor cell is transferred through physical contact into a recipient cell is known as conjugation. In the experiment, sexduction, a cross between F′ and F- plasmids, was demonstrated by mixing the donor and recipient, diluting them and using selective plating methods. The plasmids from the donor, recipient and transconjugant were isolated and analyzed…

The effect of the BsrG1 restriction enzyme on Wild Type and Mutation 1 of E. coli DNA Introduction: What a lac operon is involved in the lactose metabolism of E. coli and it can only work when there is no glucose present to interfere with the lactose metabolism. (Khan Academy) E. coli chooses prefers glucose and other "better" sugars, so if any are present other than lactose the lac operon will not be expressed in the plasmid. (Khan Academy) A plasmid is an "independent, circular,…

Andrew Wittman Biology 152 Lab Section 409 3/23/2015 PURIFICATION OF SPERM WHALE APOMYOGLOBIN AND THE ORIGIN OF ITS HELICAL FOLD Abstract The purpose of this research is to understand how secondary structures of a protein, in this case sperm whale apomyoglobin, affect the denatured state of that protein. The scientific community has been working under the impression that once denatured by urea, a protein loses all of its secondary structure. In this research the effect that apomyoglobin’s…

Joshua K. Westervelt Dr. Fair MCB 4404 11-13-17 Scientific Article Analysis Questionnaire A. Read the abstract to get an overview of the article. B. Read the entire article and write notes from each section (Introduction/ Materials-Methods/ Results/ Discussion). Always refer back to the abstract if you get lost in the main sections of the article. C. Then answer following questions (also see “Explanation of Article Sections” below). ABSTRACT/OVERVIEW QUESTIONS: 1. Who did the research, and…

The importance of noncoding DNA sequences Since the completion of Human Genome Project in 2003, it was found that more than 98% of human genome is occupied by noncoding DNA sequences (Genome.gov, 2003), existing between genes and as introns within genes (Figure-1). In genomic, noncoding DNA regions are defined as the sequences of an organism’s DNA, which do not code for proteins. Although it has been known for decades that some of these sequences code for noncoding RNAs that…

Final Exam Bacteria’s gene is only coding (makes a protein) meaning one gene equals one protein. Bacteria’s life history is a short lifespan, reproduces quickly in large number of individuals. Griffith finds that bacterial cells can be transformed. (Raven) There are two forms of bacteria, one that causes pneumonia and a nonvirulent that does not. The nonvirulent lacks enzymes to manufacture the coat of polysaccharide. Griffith performed a series of experiments with these types of bacteria on…

this experiment, E. coli was introduced to two plasmids: pUC18 and lux. Plasmid pUC18 contains a gene that codes for the enzyme beta-lactamase which renders ampicillin and some other antibiotics inactive. Plasmid lux found in V. fischeri contains an operon that codes for luciferase, an enzyme that is involved in a light creating reaction. Within this experiment CaCl2 was used to increase E. coli’s ability to take up plasmids. Once E. coli was able to take up pUC18 and become resistant to…

This can be seen because the tubes that contain only the lactose showed higher enzyme activity and bacterial population size as observed from the Abs420 and OD600. In a lac operon system, a repressor molecule binds to DNA, which prevents gene expression by blocking transcription essentially turning the gene off. However, lactose can bind to the repressor molecule and remove it, so it would start transcription. This system…