BIO230H1 Chapter Notes - Chapter 1: Cytosol, Two-Dimensional Gel Electrophoresis, Gene Expression

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Control of gene expression - an overview of gene control. The different cell types of a multicellular organism contain the same dna. Different cell type synthesize different sets of rnas and proteins. Many processes are common to all cells, and any two cells in an organism have many gene in common. Some rna and proteins are abundant in the specialized cells in which they cannot be founds elsewhere. A typical human cells expresses 30-60% of its genes. Difference in gene expression between cell types are revealed through methods that directly display the levels of proteins. External signals can cause a cell to change the expression of its genes. Each cell can alter the pattern of gene expression in response to extracellular signals. Different cells respond f=differently to the same outside signal. Some features do not change no matter what the signals are. Gene expression can be regulated at many sites in the pathways from dna to rna to.

Related Questions

Ploidy refers to the number of complete sets of chromosomes (genes) present in a cell. The number of chromosomes in a complete set is a fixed characteristic of a species. Humans are diploid with two sets of 23 chromosomes. Fruit flies are diploid with two sets of 4 chromosomes. Sexually reproducing organisms are diploid, each somatic cell of an organism has two complete sets ("di" is a prefix indicating 2.). To complete a life cycle and reproduce new members of a species, mating is required. Mating brings a donation from a male and a donation from a female together. However, if the male and female cells remain diploid, the fertilization will result in a tetraploid zygote. In general, these are not viable. A mechanism is needed to form special haploid cells, gametes. The diploid set is split precisely into two complete haploid sets. That mechanism is meiosis.

The complete set of chromosomes of a species is also the complete set of genes of a species, the genome. (Yes, there is a minor contribution from mitochondria and chloroplasts. Inheritance of this information is "cytoplasmic".)

Please answer the following questions:

1. How many chromosomes in a brain cell of a fruit fly? How many chromosomes are in a liver cell of a human? Explain both answers.

2. How many chromosomes are in a fruit fly unfertilized egg? How many chromosomes are in a human egg? Explain both answers.

3. Why is meiosis necessary for sexually reproducing organisms? How many chromosomes are in a human zygote? Relate the two answers.

4. What is a gene allele? Suppose there is a gene called "bingo" and it is present once in a complete haploid set. How many alleles of "bingo" does a diploid individual have? How many copies or versions of the gene "bingo" are present in a diploid individual?

5. Modern DNA sequencing clearly identifies alleles by showing the different DNA sequence of each allele. These alleles may be termed structural alleles (I coined the term for this problem.). Classical genetics only dealt with phenotypes or visible traits. As a result, alleles of genes were identified by functionality, usually normal or non-functional. Using your knowledge of gene structure and gene expression, postulate a relationship between structural alleles and functional alleles. (include relative amounts; more, less, or equal).

HELP ASAP; Please help me understand my lab results, so be detailed to clearly understand

Then , Please include answers to the question below to include in your response

1. what role does ampicilin (amp) and arabinose (ara) play in the experiment.

2) Because GFP was isolated from jelly fisht, what modification to the GFP DNA had to be made to result in expression in E. coli?

BACKGROUND INFORMATION

Transformation of GFP and the pGLO Plasmid GFP is a commonly used reporter protein in research labs, as the fluorescence creates a marker protein that can be used in many types of cell biology and biochemical studies. In basic research, GFP is often fused to a specific target protein of interest, creating a chimeric reporter protein. GFP has been used as a reporter protein to study blood vessel and tumor progression in mice, brain activity in mice, and malaria eradication in mosquitoes for instance (see website mentioned in notes). In the first week you will use a procedure to genetically transform bacteria with the gene that codes for Green Fluorescent Protein. Following the transformation procedure, the bacteria express their newly acquired jellyfish gene and produce the fluorescent protein, which causes them to glow a brilliant green color under ultraviolet light. During the second week you will purify the protein away from all of the other proteins produced by the bacteria using chromatography, and during the third week you will evaluate the success of the purification procedure and estimate the size (molecular weight) of GFP by using sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE). Fundamental to the process of genetic transformation of bacteria are plasmids. In addition to one large chromosome, bacteria naturally contain one or more small circular pieces of DNA called plasmids. Plasmid DNA usually contains genes for one or more traits that may be beneficial to bacterial survival. In nature, bacteria can transfer plasmids back and forth allowing them to share these beneficial genes. This natural mechanism allows bacteria to adapt to new environments. The occurrence of bacterial resistance to antibiotics is due in large part to the transmission of plasmids which contain antibiotic resistance genes. The pGLO plasmid contains the gene for GFP, and also contains the gene for the enzyme Î²-lactamase (bla), which provides resistance to the antibiotic ampicillin. The Î²-lactamase protein is produced and secreted by bacteria that contain the plasmid. Î²-Lactamase inactivates the ampicillin present in the LB nutrient agar, allowing bacterial growth. Only transformed bacteria that contain the plasmid and express Î²-lactamase can survive on plates that contain ampicillin. Only a very small percentage of the cells take up the plasmid DNA and are transformed. Untransformed cells cannot grow on the ampicillin selection plates. pGLO also incorporates a special gene regulation system, which can be used to control expression of the fluorescent protein in transformed cells. The gene for GFP can be switched on in transformed cells by adding the sugar arabinose to the cellsâ nutrient medium. Selection for cells that have been transformed with pGLO DNA is accomplished by growth on antibiotic plates. Transformed cells will appear white (wild-type phenotype) on plates not containing arabinose, and fluorescent green when arabinose is included in the nutrient agar medium.

The transformation procedure involves three main steps. These steps are intended to introduce the plasmid DNA into the E. coli cells and provide an environment for the cells to express their newly acquired genes. 1) Cells are first treated with a solution of CaCl2, which is thought to neutralize the repulsive negative charges of the phosphate backbone of DNA and the phospholipids of the cell membrane, allowing the DNA to adhere to the cells. This is referred to making the cells âcompetentâ (i.e. the cells are capable, or competent, to take-in exogenous DNA). 2) Cells are then subjected to a heat shock, which is thought to increase the permeability of the cell membrane, allowing the cells to take-in the plasmid DNA. 3) Cells are allowed to grow in a ârecoveryâ phase in the absence of ampicillin. During this time the cells begin to produce the Î²-lactamase protein, which will allow them to survive when they are subsequently placed on agar plates containing ampicillin.

For the first week section of lab

To eac

h of two microfuge tubes, add 250ul of transformation buffer. Keep these tubes on ice.

Using a sterile loop, pick one colony of bacteria from the LB plate. Transfer this colony to one of the microfuge tubes.

Gently vortex the tube until the colony is dispersed. Repeat for the second tube. Add 0.08ug of DNA to one of these tubes (+DNA tube).

Incubate both tubes on ice for 10 minutes. Incubate both tubes at 42Â°C for 50 seconds.

Incubate both tubes on ice for 2 minutes. Add 250ul of LB broth to each tube and incubate at room temperature for 10 minutes. Flick each tube gently. Add 100ul of t

his transformation mix to the appropriate plates.

Results For plates:

+DNA: Has the E. Coli pGlo plasmid and - DNA plates do no have EColi pGLo plasmid .

Amp means ampiclin and Ara means arabinose on agar plates

+ DNA Plate LB/amp/ara--> white 9 colonies, Glow: yes

+DNA LB/amp--> 7 colonies, GLow: no

--DNA LB/AMP- 1 colony so no colony growth and no glovw

-DNA: LB--> many colonies, Glow: no

Please explain significance of result or thand the reason for the results in scientific terms based on the background information provided and your own knowledge to be detailed. Would these results be expected as wll.

*Please don't answer with photos, DO NOT UPLOAD PHOTO, it's hard to read.

I post this question twice, please don't answer this post if you already answer the other one, if you can answer different answer that's fine. REASON WHY I POST IT TWICE, I NEED TWO DIFFERENT VIEW.

Discussion

Hi All - this week you will learn about DNA - the molecule of life! You may think that protein-coding genes are the most important, but results from the Human Genome Project revealed that only about 2% of our DNA codes for protein - so what about the rest of the "junk DNA" (or non-protein coding portion of the genome) - is it functionally important? Yes! Scientists are learning how "the non-protein-coding portion of the genome is of crucial functional importance: for normal development and physiology and for disease". I would like you to please choose a topic with regards to the non-protein coding portion of the genome (this will introduce you to gene regulation which we will cover in chapter 11) or you may also choose to write about a topic that describes a mutation in any protein that is involved in DNA replication, transcription, or translation (we did not talk about all of the enzymes involved in those processes). Please list your reputable source - this is worth 0.5 pt (even if you use one of my sources below) and tell me WHY you chose your topic (this is worth 1 pt.) please try to briefly explain your topic to the best of your knowledge - I don't expect you to write a lot of detail about your topic - it might be hard to understand (which you are welcome to comment on in your paragraph)!

Examples to choose from (but not limited to) include: noncoding RNAs (snRNAs, miRNAs, siRNAs, snoRNAs, piRNAs, lincRNAs) and RNA therapeutics:

LIST:

1. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4119351/ (Development of microRNA therapeutics is coming of age)

2. http://www.umassmed.edu/rti/ (RNA Therapeutics Institute)

3. http://www.genengnews.com/insight-and-intelligence/rna-based-therapeutics-and-vaccines/77900520/

4. http://genesdev.cshlp.org/content/26/21/2361.full (Biology of PIWI-Interacting RNAs: new insights into biogenesis and function inside and outside of germlines)

5. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4265212/ (PIWI proteins and their interactors in piRNA biogenesis, germline development and gene expression)

6. http://www.news-medical.net/news/20121203/microRNAs-play-an-important-role-during-embryonic-development.aspx

7. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4578617/ (the role of microRNAs in cell fate determination)

8. http://news.berkeley.edu/2017/01/13/scientists-reprogram-embryonic-stem-cells-to-expand-their-potential/

9. http://www.the-scientist.com/?articles.view/articleNo/40871/title/The-Second-Coming-of-RNAi/

10. http://web.mit.edu/newsoffice/2013/cardiac-development-needs-more-than-protein-coding-genes-0124.html (long non-coding RNA molecules)

11. http://www.alzforum.org/news/research-news/new-role-micrornas-torpedoes-sink-neurons(microRNAs)

12. http://ghr.nlm.nih.gov/condition/rothmund-thomson-syndrome (mutation in human helicase gene)

13. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3633371/ (mutation in mitochondrial helicase gene called TWINKLE)

14. http://sfari.org/news-and-opinion/news/2013/in-autism-related-disorders-rna-turns-out-to-be-key (RNA topoisomerase)

15. http://ghr.nlm.nih.gov/gene/TERC (dyskeratosis congenita - mutations in the TERC gene - the RNA component of telomerase)

16. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3853347/ (Top3beta is an RNA topoisomerase that works with Fragile X syndrome protein to promote synapse formation)

The following 3 articles discuss long non-coding RNAs - there are many examples in each article so you only need to talk about one example - not the whole article:

1. http://www.sciencedirect.com/science/article/pii/S2468054016300063 (mechanism of action and functional utility)

2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5084630/ (dysregulated expression in ovarian cancer)

3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4736767/ (stem cells)

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BIO230H1 Chapter Notes - Chapter 1: Cytosol, Two-Dimensional Gel Electrophoresis, Gene Expression

BIO230H1 Full Course Notes

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