4
votes
1answer
81 views

Can anti-aging cream work?

I have a friend who told me that anti-aging cream cannot work to reduce wrinkles as it only penetrates x amount of skin layers and can never make a long term effect. Me not knowing much about how ...
5
votes
1answer
85 views

Stretching and compressing bones

The Young's modulus of elasticity when a bone is stretched is : 16×109 and when it is compressed, it is 9×109 N/m2. That means, change in length will be more if you compress a bone as compared to ...
6
votes
1answer
2k views

How does a sperm cell die?

What causes an animal sperm cell to die? Does it die somehow from being outside its original environment? I've studied the Wikipedia page on sperm and I see a lot of information on what makes up a ...
3
votes
1answer
112 views

Proteins in Milk, Oat , Eggs and Soy

I have read that there are proteins in oat which are similar to those in soy, milk and eggs. I know nothing about biochemistry, and I'm struggling to decipher the info i find.. the closest Ive got to ...
0
votes
2answers
50 views

Can someone link me to resources on the efficiency of sticky end ligation?

I really would like to know if sticky end ligation could potentially be performed with very high efficiency, and which factors influence that. However, I can't find any papers on the subject, even ...
3
votes
1answer
77 views

Reconstruction of wildlife distribution based on poorly-sampled data [closed]

cross-posted to Signal Processing, Cross Validated, and World Building Stack Exchange Hi, I thought I'd also put this here in case there are any field biologists with ideas on the matter. Problem: ...
0
votes
0answers
83 views

Medical Uses of toxic venom

One interesting thing I recently learned is that venom has medical uses that can actually save lives! But from what I see so far this either applies to venoms from creatures that are not fatal to ...
3
votes
1answer
327 views

What happens to the precursor protein's signal sequence after it is cleaved?

Where does this signal sequence "go" after it has been cleaved by signal peptidase and what is its next function?
6
votes
2answers
2k views

Why is the opposite of plantar flexion called “dorsiflexion”?

Why is the action of flexing the foot so that the toes move anteriorly/superiorly (i.e. in the direction opposite that which they move during plantar flexion) described as "dorsiflexion"? In the same ...
0
votes
0answers
100 views

Why does a human's field of view narrow when moving faster?

A relative of mine is a driving instructor and he regularly likes to bring up that the field of view narrows noticeably when driving at higher speeds. Is this true, why is this so and does this apply ...
5
votes
1answer
145 views

Telomerase as cancer target

There are a lot of publications, starting from 2000, about using telomerase for targeting cancer cells (it is upregulated in more than 80-90% of tumor cells). Specifically using its promoter (hTERT). ...
2
votes
0answers
59 views

CRISPR Knock in

Using the CRISPR/Cas9 technology, it is possible that after inducing a DSB with the Cas9 endonuclease guided with an RNA designed by the user and using a template DNA, get a desired Knock-In (KI) by ...
1
vote
1answer
221 views

Hydrogen peroxide decomposition and catalase uses [closed]

All google searches have simply returned more info on catalase. I'm looking for a catalyst that isn't found inside living organisms which can break down H2O2. Looking for any resources to look at, or ...
4
votes
1answer
64 views

By what mechanism does Risperidone swell breast tissue?

There has been much talk of the anti-psychotic drug Rispeirdone causing un-natural breast tissue growth as well as galactorhea (milk production). Especially in young men and boys. What is the ...
9
votes
3answers
431 views

How can I align more than 2 sequences locally?

ClustalW and Omega of EBI and Blast of NCBI, both globally align sequences. Smith waterman of EBI aligns sequences locally, but works with just two sequences. How can I align more than 2 sequences ...
4
votes
0answers
118 views

Are there any de-novo genome assembly programs for HADOOP?

I have access to a small (approx 20 nodes) cluster that has HADOOP running on it, and I need to do some de-novo genome assembly. I'd like to ask is anyone knows of any program that can do this on a ...
9
votes
1answer
2k views

Why are butterflies drinking blood?

According to this video, butterflies sometimes drink blood. Do they have the organs necessary to digest blood? I thought they eat only salts and nectar, which are easy to digest compared to proteins. ...
2
votes
0answers
25 views

What is the role of RAGEs?

According to articles I read, AGEs (advanced glycation end products) activate RAGEs (receptors for AGEs). This activation increases the ROS (reactive oxygen species) levels in the cells. 2003 - ...
7
votes
2answers
388 views

Do butterflies see behind?

Butterflies, like many other insects, understand that I am getting near from behind. How do they feel this - through vision, hearing, or some other sense?
2
votes
0answers
33 views

Is (are) there any crucial gene(s) for the formation of flower in flowering plants? [closed]

I am interested in qualitative (flowers of some plants have petal or sepal, but some plants have not) and quantitative (number of flowers of plants) differences between flowers of different plants. ...
3
votes
1answer
129 views

What type of flask should I use to culture NTERA2 embryonic cancer stem cells?

I'm just starting my MSc research and I am in the process of making a list of equipments/consumables to order. Is there a specific flask in which I can culture NTERA2 (NTERA2/D1) cell line?
1
vote
3answers
2k views

When is the second polar body extruded from the egg nucleus?

When does the second polar body gets expelled from the egg nucleus during oogenesis ? I know that it occurs after the entry of the sperm into the secondary oocyte but does it occur before the ...
5
votes
1answer
180 views

Is hands-only CPR as effective as traditional CPR?

Is hands-only CPR as effective as traditional CPR ? Wouldn't 30 chest compressions + 2 rescue breaths be more effective if the person doesn't have a pulse AND not breathing? From my understanding (...
1
vote
1answer
182 views

Yeast absorption of different spectra of light

I'd like to monitor the growth of a yeast population by shining light through it and monitoring the change in light that gets through as it grows. I'm not sure if I should use IR, or any particular ...
4
votes
2answers
92 views

How can (or did) Deinococcus radiodurans continue to evolve after developing resistance to mutation?

Deinococcus radiodurans has a remarkable ability to resist damage to its DNA due to radiation, dehydration or (to my knowledge) any other source. It keeps multiple copies of its genome and has a ...
1
vote
1answer
107 views

What are genome wide functional linkages?

There are two types of interaction classifications used to describe Protein-protein interactions, namely physical and functional. Whilst physical interactions are obvious in nature and methodological ...
13
votes
2answers
903 views

Do transcription factors bind to both strands of DNA?

Do transcription factors (or generally proteins) bind to only single strand of DNA or both strands? Since it can have non covalent bonds to both strands in theory. I would like to know the mechanism. ...
7
votes
1answer
87 views

Do DNA repressors exist?

I know about enhancers and the mechanism that lead them to increase the gene expression of their targets but I was wondering if similarly DNA repressors exist. I know about protein repressors but I am ...
6
votes
1answer
74 views

“Enhancers” of enhancers?

I am looking for examples (if any) of genomic regions which regulates the activity of enhancers, either augmenting or reducing it. Essentially some kind of enhancers (or repressors) of enhancers to ...
6
votes
2answers
5k views

What physiological processes within a muscle cause the latent period in a muscle fiber?

This is a lab question I cant find the answer in the lab manual or in the text book. What physiological processes in a muscle cause the latent period in a muscle fiber? Please help. Edit: The latent ...
0
votes
2answers
161 views

books for beginners in research in mathematical biology [closed]

I am a M.SC(mathematics) student. I have no subject like mathematically modelling.But i'm interesting in research in mathematical biology.Initially which book i should study. Please guide me.THANKS......
4
votes
2answers
88 views

Questions on DNA damage

I'm not strong in biology, so bear with me on this: I've been reading that as we age, our DNA is damaged by internal (e.g. errors during replication) and external (e.g. sun damage or radiation) ...
2
votes
1answer
93 views

How did bullying arise evolutionarily?

By bullying, I mean individuals harassing others with name-calling or violence but not for the purpose of gaining resources such as with extortion or theft. The only explanation I've thought of is ...
8
votes
1answer
264 views

What sample sizes are ideal for carrying out Bayesian Skyline Plots?

I am interested in creating Bayesian Skyline Plots to look at demographic changes in certain population groups. However, these populations have very little within population variation. Around 5 ...
5
votes
2answers
123 views

Help with STRING database data

I'm working with data downloaded from STRING database (string-db.org) for protein-protein interactions. My idea is to compare the topology of connections of the same protein on different organisms. ...
5
votes
2answers
618 views

What happens during kefir fermentation process?

I’ve found many sources about the positive effects of kefir for the digestive system. However I haven’t found any information about the fermenting process. What is the exact biology (chemistry?) ...
13
votes
2answers
3k views

What is the explanation for the smaller number of tRNA than codons?

Translation, or decoding, of the four-nucleotide language of DNA and mRNA into the 20–amino acid language of proteins requires tRNAs and enzymes called aminoacyl-tRNA synthetases. To participate ...
5
votes
1answer
261 views

Why is E.coli used as a model?

Is there a reason for the choice of E.coli as a model for many bacterial systems? Other bacteria such as B.subtilis are also used, but why is E. coli preferred?
1
vote
1answer
38 views

How to correlate the pattern by which CAP activator from E.coli binds to DNA and its mechanism of action?

The catabolite activator protein (CAP) activates the expression of more than 100 genes involved in secondary sugar metabolism in E.coli. Apparently, it always binds in sites that are away from -10 and ...
3
votes
1answer
593 views

What causes the line patterns in the palm of the hand?

The line patterns on the hand are unique to each individual, but what causes these lines and re they advantageous in anyway?
3
votes
2answers
234 views

Is there a specific mechanism for the delivery of pain medication?

For example, when one takes aspirin or ibuprofen does the chemical get dispersed to all pain receptor? My question really is, how does the chemical know where to target in the body? I figure wherever ...
4
votes
1answer
108 views

Is there a DNA analogue to ribozymes? [duplicate]

If not, is it impossible for DNA to have enzymatic activity?
1
vote
1answer
99 views

How long the homologous arms of the “repair” sequence must be to do homologous recombination? [duplicate]

I am trying to figure out the details of the homolougous recombination in order to be able to insert a certain piece of DNA in the host genome after double strand break.. Does anybody know how long ...
3
votes
1answer
127 views

How would you affect bulk DNA gene therapy for a human?

Let's imagine that we understood DNA programming and our genome very well and realized that there were some significant flaws (we die, we need sleep, etc.) And let's imagine that we understand how to ...
7
votes
3answers
184 views

Mechanism by which $lacI^{d}$ is a dominant mutation, impairing the function of normal copies of the Lac Repressor

Jacob-Monod model for the lac Operon was based on experiments using two strands of bacteria which constitutively expressed $\beta$-gal: $I^{c}$(mutation in the gene lacI , which encodes the repressor) ...
0
votes
1answer
97 views

Incubation time of Antarctic Phosphatase in lab [closed]

Antarctic Phosphatase is used to catalyze the removal of 5' phosphate from DNA. If I'm using it in the lab on a sample of 1-5 micrograms of digested DNA, how would I figure out how long to incubate ...
6
votes
1answer
7k views

Is consuming proteins different vs. consuming amino-acids and how?

Yesterday I had a discussion with a friend. He said that consuming proteins and amino-acids is different. He said that those who grow muscles would agree on that. I wanted to argue against that ...
2
votes
1answer
126 views

Atelectasis due to decreased surfactant in lungs

Surfactant is a protein lipid mixture produced by alveolar pneumocytes composed of Dipalmitoyl Phosphatidyl Choline lipid, apoproteins and calcium ions. This surface lines the alveolar epithelium ...
9
votes
3answers
162 views

What triggers the migration of robins?

I live in central Massachusetts, and have begun seeing robins, as we generally do in early March. The temperature is well below normal, though, and three feet of snow are covering the still-frozen ...
5
votes
2answers
349 views

What is the IC50 exactly?

I am reading the paper "Activity of the bcr-abl kinase inhibitor PD180970" but I don't understand how IC50 works on table 1. Can you tell with simple words and give me an easy example?

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