1
vote
1answer
154 views

What is the energy balance of cooking?

If I cook some food, I get apparently several energetic advantages: thermal : the temperature of the food is closer or superior to the temperature of my body or internal organs, so I do not have to ...
2
votes
1answer
90 views

The oldest common ancesstor of all human beings

Do all human beings have a single oldest ancestor (a man and a woman), or were there were many ancestors at the same time at different places on earth? This article sheds some light. Is there another ...
4
votes
1answer
759 views

What does conditional analysis of a SNP in a GWA study entail?

I am familiar with the use of tag-SNPs in genome-wide association studies to identify gene loci involved in complex traits, but I keep seeing the term "conditional analysis" used without any ...
0
votes
2answers
198 views

Deterministic model of lambda-phage lysis/lysogeny [MATLAB] [closed]

Project 1 Base: Can someone please help me understand what I need from Project 1 Base code to do questions 1 and 2 from the first image? I'm new to MATLAB so a thorough explanation would be ...
2
votes
1answer
446 views

Manipulation of gene expression using VP16 fusion and engrailed fusion to a transcription factor?

Today, a presenter briefly mentioned that gene expression in sea urchins during development might be manipulated using VP16 and engrailed fusions. On a slide, it said that expression might be ...
1
vote
1answer
1k views

What would be the best design for spike-and-recovery and linearity-of-dilution validation experiments in one 96-well ELISA plate?

I have searched in the web for a detailed explanation of doing such validation experiment, but unfortunately couldn't find a satisfactory one. I came across the following sources: Thermo ...
1
vote
1answer
89 views

Reproductive isolation causing evolution

My course book says about reproductive isolation that it does not allow the interbreeding among the individuals of different species. It also says that it is a cause of evolution. How is this cause ...
0
votes
1answer
152 views

Why does the PR form of phytochrome exist?

I know how it gets converted because PR is more stable and when there is neither red or far red light PFR naturally converts to PR. But what is the point of it? If PFR is the biologically active one ...
1
vote
1answer
177 views

What insect is this?

I found it in Russia. Where they usually live? What they eat? Full length is approximately 2 cm.
1
vote
2answers
166 views

How long can you keep sheep eyes in formaldehyde before dissecting?

We're preparing for an experiment in our classroom and my teaching partner and I are at different points in the unit. I am concerned that the experiment will be less successful because of the ...
1
vote
1answer
2k views

Is episome a plasmid or a virus?

A plasmid is a small DNA molecule that is physically separate from, and can replicate independently of, chromosomal DNA within a cell. In general, in eukaryotes, episomes are closed circular DNA ...
2
votes
0answers
82 views

How do omega-3 fatty acids reduce cholesterol at the molecular level?

I have heard that omega-3 fatty acids found in fish are a good way to prevent/reduce cholesterol problems. My question is how do omega-3 fatty acids do that: what are they doing on a chemical level ...
0
votes
1answer
102 views

How the concentration of an antibiotic is chosen for YPD medium?

I need to prepare YPD plates containing hygromycin, but I don't know which concentration I can use. I'll select transformants of Hansenula polymorpha.
6
votes
4answers
5k views

What is the cause of muscle cramps?

According to wikipedia, muscle cramps are caused by myosin fibers not being able to break free from the actin filaments during contraction, resulting in a prolonged contraction. Obviously a lack of ...
2
votes
1answer
59 views

PTMs of proteins via mass spec?

I understand that mass spec is widely used to study PTMs like glycosylation of proteins, but how can mass spec determine correct PTM structure of say glycosylation if two glycan structures have the ...
1
vote
1answer
122 views

What causes peanut allergies?

Surveys show that 0.6 percent of the US population has an allergic reaction to peanuts. This prevalent allergy has even prompted some to ban peanuts from schools altogether. I am completely ...
2
votes
3answers
110 views

What biochemical molecule viewer allows for changes in amino acids and resulting tertiary structure?

I am familiar with the Jmol, Rasmol and PyMoL softwares, and was recently introduced to BioBlender. However, I am completely unaware if any of these programs (or others) are capable of loading a .pdb ...
3
votes
1answer
73 views

What is the translation termination efficiency in mammalian cells?

When I express proteins in bacteria I put at least two stop codons at the end of the gene to increase the termination efficiency. Is this the case in eukaryotic cells too? If I put a single stop codon ...
2
votes
1answer
420 views

Where to put the gene after eukaryotic promoter for best expression levels?

As far as I know there is an optimum distance between a promoter and the gene for the best expression levels. What is that distance for common promoters like CMV, SV40? If you have a first hand ...
0
votes
1answer
25 views

Is there any relation between weight class and extreme lifting performance in O-lifting?

We usually thought that weightlifting is a tough game. It is only for great physique. There are 6 man in history who lifted 3 times their body weight. Check here. 3 of them are Bantamweight(56kg), ...
2
votes
2answers
448 views

Iron deficiency anemia symptoms explanation

In my classes and on the internet, brittle nails and dry hair (or hair loss) are described as symptoms of iron deficiency anemia, but none explains the cause of such symptoms. Does anyone have any ...
1
vote
1answer
687 views

Problems with analysis of small RNAseq data - Adapter trimming

I have always faced a problem while analyzing small RNAseq data, at the step of adapter trimming. Overview of small RNAseq (Illumina) RNA is size fractionated using columns or PAGE 3' and 5' ...
0
votes
1answer
69 views

Free/cheap DNA sequencing options for developing countries? [closed]

I would like to know what are the options for an average person in a developing country to get access to this technology, and be able to get their genome sequenced.
4
votes
1answer
190 views

Can I heat Trizol?

I wonder if I can heat Trizol reagent for 30 min 65C. The goal is to disrupt protein-RNA complex while inhibiting nucleases. (I can't use RNasin cause it's inactivated in 65C, and can't use RVC cause ...
9
votes
2answers
302 views

Chiral (a)symmetry of curly hair (and fur)

Some people have curly hair, as well as fur of some animals can be curly. However, shapes which are curly are not mirror symmetric, much alike screws or chiral molecules. The question is whether ...
2
votes
1answer
102 views

Is it possible to pet/groom birds?

I wonder if it's possible to pet a domestic crow, or an owl. Do birds respond to grooming as cats or dogs, for example? If so, then how does one pet a bird?
2
votes
1answer
89 views

Confusion related to a term probe-by-background interaction

I was reading a paper related to bioinformatics where it uses the drug response on the cancer cells and the gene expression of the individual cells are studied to find any useful insights. Specially, ...
1
vote
1answer
144 views

What's the Evolutionary Purpose of Religion? [closed]

I would imagine the answer to this question would be that religion tends to cause greater compliance of individuals within society, so it is pro-society. Plus these religions tend to incorporate some ...
6
votes
3answers
11k views

Differences Between Protein Motifs and Protein Domains?

I am in a 300-level molecular biology class and am unclear about this concept and how to delineate motifs versus domains of proteins. Any suggestions would be much obliged.
3
votes
3answers
260 views

Is it possible to make bacteria vulnerable to antibiotics it's resistant to?

Since bacteria becomes resistant to antibiotics after an unfinished course, is it possible to do anything to be able to get treatment with the same antibiotic again, and reverse the resistance in the ...
0
votes
0answers
123 views

Perception of distant lights without glasses

I am fairly short-sighted and wear glasses pretty much all the time. Naively, I would expect that when I take my glasses off, the image I see should look very much the same as as a photograph that's ...
4
votes
1answer
136 views

How do the variable portions of antibody genes look in cells which don't produce antibodies?

There are several families of antibodies found in mammals. They may have two or more antibody domains which contain heavy and light chains. The variable regions of the light and heavy chains genes ...
0
votes
1answer
81 views

When is wing growth in the bat complete and how soon can bats fly after wing growth is complete?

I was reading this paper by Cretekos et al (2008), in which they state that wing development in the bat is not complete until after birth - the wing continues to elongate postnatally. This would ...
4
votes
1answer
116 views

How do you store membrane proteins?

We're producing some membrane proteins and they aren't amenable to freeze thaws even when we add glycerol. The proteins are solubilized in detergent above the cmc so they should be in micelle form in ...
2
votes
1answer
309 views

How exactly does marijuana damage brain cells?

I've heard that THC can cause permanent damage to brain cells. I've also heard this reffered to anti drug propaganda. Another theory i've read is that temporary effects reduce intelligence but long ...
6
votes
1answer
60 views

What controls the southern range of willows?

Many willows (Salix spp.) grow in northern states but do not grow in southern states, for example Salix viminalis. What mechanisms control the southern range of temperate hardwoods such as willow? Is ...
1
vote
1answer
159 views

Cyanobacterial photosynthetic oxygen yield

I am somehow not convinced that biotic factors are solely responsible for creating 21% of atmosphere (around 40 million moles of oxygen). There may be additional issues here. Since cyanobacteria ...
0
votes
0answers
53 views

Western blotting of lung samples [duplicate]

I have been working on lung samples to perform western blotting. I have two related questions about this: I get very nonspecific results: at times nothing at all, at times it glows on membrane but ...
1
vote
1answer
135 views

How do axon terminals report to the soma?

It is important to bear in mind that the distance between a neuron's axon terminal and its soma can be extensive, up to about 1m in the human body. The fastest transport along the axon is 400mm/day ...
2
votes
3answers
1k views

How did this spider evolve to mimic exactly a human face and arms?

So I came across something terribly amazing today, that is, a video showing this species of peacock-spider, that literally, transforms into a human face waving his arms about. What could have ...
3
votes
1answer
120 views

What is range of the number of individual organelles in cells

What is the range of the number of individual organelles in a cell? I am not a biologist but I understand that there's one nucleus and sometimes lots of mitochondria, so I am after the total number. ...
2
votes
1answer
342 views

Strange behavior of a DNA gel

I ran a PCR product of ~300 bp on a 2% TAE-agarose gel for 30 minutes. I used Sybr-safe as a DNA stain. Voltage was 80V. When I imaged the gel, the DNA on the bottom half of the gel, including the ...
6
votes
2answers
2k views

Why does plucking nose hair cause tears in the eyes?

It's not a particularly sad or painful thing to pluck a few nose hairs, but it's common for the tear ducts to wet up when doing this. I would like to know the physiological reason for the ...
1
vote
1answer
175 views

Parthenogenesis in Bees

Parthenogenesis is defined as: "A type of asexual reproduction in which egg develops without fertilization to form a new individual." If parthenogenesis takes place in bees, a drone or male bee is ...
1
vote
1answer
140 views

Why does contracting the iris allow less intense light to go in?

The iris contracts automatically in the presence of bright light. This makes a flashlight appear bright in darkness, but outside in daylight you can't even see it's light. The iris is changing your ...
2
votes
2answers
610 views

How prevalent is Taq polymerase in adding 3' A overhangs to the PCR product?

I am conducting a mutagenesis on a gene in vivo of which I need to ligate into an expression vector. The primers I have designed overlap restriction sites of which I plan to use to ligate into the ...
0
votes
1answer
271 views

Definition of Dye- Reduction Test?

Can some one give a simple explanation or definition on what a dye-reduction test is.
5
votes
1answer
213 views

Are there eukaryotes without introns?

This question on the function of introns in eukaryotic genes made me think: I know that more basal organisms have smaller introns and fewer alternatively spliced exons compared to mammals. But are ...
6
votes
3answers
732 views

What percentage of protein isoforms have different functions?

I am looking for studies on how many protein isoforms have different functions, preferably in human. We know that a great many, if not most, of human genes are alternatively spliced and that many ...
2
votes
1answer
119 views

EGFR, sialylation, and cancer progression

EGFR (epidermal growth factor receptor) has been intensively studied in cancer and treatments have been developed to inhibit EGFR signaling. Sialylation of EGFR is known to block dimerization and ...

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