Biochemistry and Molecular Biology

All I know is that cellular mitochondria has it’s own DNA. Which confuses my simple understanding of a few things. This rather blurs my idea of what a species is. I thought, ‘one species, one DNA’ Does this mean humans are colony animals? Presumably all creatures have the same duality? The Eve study examined mitochondrial DNA (mtDNA), which is passed only by mothers to their offspring. How can DNA ‘pass’ a different (mito) DNA? Or, how does the mtDNA get into a new human then? (You’ll be ignorant about how ignorant I am, so err on the side of simplistic concision).

This is a question that I'm just a bit curious about. Yesterday morning, I got into a car accident on my way into work. I was blinded by the sun and saw something dart out in front of my car so instinctually I swerved to the right and wound up hitting a telephone pole. I was perfectly fine and nobody else was involved, but it still kind of sucked. Anyway, what has been really weird is that in my mind I keep replaying the accident and it just appears to be playing in slow motion. In addition, there is this really weird haze about the entire situation. I mean, I was there and remember it happening, but a lot of the details are incredibly fuzzy. Things such as the …

A ribozyme is: a) a protein in 30S ribosome unit. b) a RNA that hydrates proteins. c) a protein that cleaves RNA d) a RNA that splits oneself and then glues the pieces together in a new way. mRNA binds oneself to the 30S ribosomal unit: a) in a complex with GTP b) and is then modified with a cap c) together with elongating factors d) first after it has been attached to initiating factors e) none of the above. Poly-a-tail: a) Are in every eukaryote mRNA. b) Are out on the end of every gene transcript c) Exists if the transcript has a sequence which specify polyA on the 3’ end. d) Exist in the end of every gene e) Exists only in prokaryote mRNA …

How do I convert ( glucose concentration ) µg per ml into µM? For example 10 µg per ml?

Hey.. I was wondering.. I have just done a lab investigating kinetics of yeast invertase... I mixed invertase, 0.1M phosphate bufer and 0.2M sucrose (substrate) in a test tube and put it in a water bath. at 1,5,10,15 etc minutes I removed some of the invertase and added distilled water.. I was wondering.. why and how does the addition of distilled water stop the reaction occurring?

Hi, Is there any situation where one would want to use DH10B over DH5alpha competent cells? I've read that DH10B is used for methylated DNA but I'm not sure what that means.

How come IgG isotypes are used as secondary antibody for detection when performing a serum-ELISA and not IgM? It says so in a course immunology, but I can not find the underlying reason.

Hi, I have an exam this tuesday in enzyme kinetics and I have to go through an article and know how they did all the kinetic calculations. My question is how they calculated Km and Kcat values from a figure showing a double reciprocal plot of elongation rate vs EF-Tu concentration The article is 'ppGpp inhibition og elongation factors Tu, G and Ts during polypeptide synthesis' of Rojas, A-M., Ehrenberg, M., Anderson, S.G.E., and Kurland, C.G., Mol Gen Genet 1984 http://www.springerlink.com/content/m3m7250211t6g475/ It is fig 8 and the calculated Km and Kcat values are listed in table 2 I know this require that you'll spend some time reading the paper (…

I'm testing the toxic effects of a protein on a certain cell line but my results dont make any sense to me. Some background info: The protein is a blue copper redox protein native to some bacteria, involved in their electron transport. it is a redox protein, and is known to interact with cell signalling pathways through transcription factors. i did an assay measuring the cell cycle or S phase activity on the cell lines using different concentrations of the protein. In this assay, higher readings indicate higher cell cycle activity. I'm using a control with no protein where the readings from it would indicate normal cell cycle activity My results are strange. U…

Something that crossed my mind recently, can humans digest keratine-proteins (i.e hair and nails) like with other proteins, when they are broken down to individual amino acids?

hi all i have cloned 600 bp gene in pet vector in colony pcr i have got positive result ,i have got amplification in that once after expression analysis of protein with IPTG induction i am getting very less amount of expression can anybody suggest me how to improve expression of target recombinant protein thanks in advance

Something I can't quite grasp, How is it one can detect proteins in Western blot using antibodies, if the epitopes recognised by these antibodies have been denatured in the SDS-PAGE run beforehand? Are you just hoping that the epitopes are continuous or that they partially reform upon transfer to the membrane? Thanks

ok suppose i want to take a short DNA strand like this one 5-gatcctgcta-3 into RNA, and want it to be labeled. So radioactive GTP is used. And supposed if the GTP is radioactived with the additon of 4th phosphate group in the alpha postion, will the resulting RNA be radiolabeled? What about the beta position? I don't get this at all

I wanna build a model for Green Flouresent Protein (GFP). like this one in this pic BUT i need suggestion for simple tools i can use. THANX in advance

Hi, there, I am a novice in Drosophila field. I tried to extract total genomic DNA from fruit fly adults. When I run the total genomic DNA on argarose gel, there are three DNA bands, above 10 k nt (possible genomic DNA), other two small bands (1 k and 2 k, respectively). Can some tell me what are these two small DNA bands in total genomic DNA from Drosophila? Your time is greatly appreciated. Xing Li

Hello, How soon, if ever, do you believe we'll be able to predictively model an entire organism using a computer? I think it will be soon. I'm a layman interested in the subject, and I have a Google Groups page devoted to general interest literature related to Biomodeling, check it out if you have a chance: http://groups.google.com/group/bebobio?hl=en Why should we be interested in Biomodeling? The life sciences move too slowly, in vivo research is too inefficient, the data is too complex to understand using human intuition alone IMHO. Thanks in advance for your thoughts...... Off Topic - Arthur C. Clarke "sic transit gloria mundi" - Thus passes the gl…

If the melting points of these 18-carbon fatty acids are like this, stearic acid, 69.6 °C, oleic acid, 13.4 °C, linoleic acid, -5 °C, and linolenic acid, -11 °C, then what structural aspect of these 18-carbon fatty acids is associated with their melting points? And also, what would be the molecular explanation for the trend in the melting points? So I'm thinking that the reason for this is because of their double bonds. How many double bonds they have would raise their melting points! This is my first post, I wonder if I got this right

Does anyone know how the leucine-responsive regulatory protein works to regulate gene expression? From what I understand, in the pap operon in E. coli, it binds to a operator overlapping a Dam site. By blocking Dam, it prevents the expression of the papI promoter. I don't understand how the protein functions, however. The paper I'm reading doesn't really go into detail about it.

does anyone know how many ribosomal RNA yeast have??? usually when i extract the RNA, i only get 2 intact bands (28S & 18S).. BUT somehow, when i do the RNA extraction, i will get 3 bands... there are another band 'upper' than the 28S rRNA...(but it is not genomic DNA because i run the RNA with 1kb ladder and the size of the 'upper band' is around 4.5kb...) does anyone know about the band???? please help me.. when i measure the absorbance of my RNA, usually i will get a good reading of A260/280 which is around 1.8-2.0....but A260/230, usually i will get around 1.40-1.70... how can i get rid of the polysaccharide contamination????? any suggestion???? p/…

please inform the function of polymerase and neuclease. why there is mismatces in dna coding if there is uracil in dna?

please help me. what is the function of polymerase and nuclease? why there is mismatches in dna coding if there is uracil?

Could you use unitary operators to study for possible convergent processes from the genome into the proteome? Such as at the gene level you will have the information for say eye color existing, this of course operates within a dynamic system.

Hello, What do we know about aging? What are latest findings? I start but my knowledge on this issue may be a few years old ... 1- One of theories is telomere shortening that as far as I know has been shown is related to some forms of pathologic aging. But not all cells divide at the same rate, what about neurons what cause them to be lost in process of aging 2- It has been suggested that some proteins known as Heat shock proteins that help to preserve conformation of cellular proteins may be associated with aging. Their expression decrease with aging. Dose it mean if we could lower temperature of body and prevent local hyperthermia we would much longer. If I recall…

For some reason this seems like a lil ridiculous since I thought about it while I was driving but here goes... So the AIDS virus preferentially attacks T-cells and being a retrovirus has RNA that is translated to DNA via reverse transcriptase which in turn is incorporated into the host cell's genome which codes for the viral structure proteins. The fact that it's preferential for the T-cells means that it preferentially binds with a receptor?/glycoprotein?/sugar? that specifically on the outside of the T-cell. And now the question... Can you design a liposome with the receptors the virus recognizes incorporated into the membrane and thus will attack instead…

What post-translational modifications play a role in intracellular signalling?