6
votes
1answer
6k 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
118 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
160 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
337 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?
9
votes
1answer
514 views

RNA migrating slower than DNA on Formaldehyde Gel?

So I ran into an interesting problem. I'm getting a linear DNA band that is twice as long (4x bases, but as denatured probably only 2x) as an RNA band running at the same size in a formaldehyde gel. ...
1
vote
0answers
38 views

Why do contrasts during CT scans make the body feel warm? [closed]

Why do the contrasts used during CT scans make the body feel hot/warm? I think they use iodine, so why would the bodies response to iodine be a warm sensation? In addition, I think they make one's ...
3
votes
1answer
41 views

Why is knowledge of bacterial pathogenesis important? [closed]

Why is knowledge of pathogenesis increased more and more for common bacterial pathogens? Most of these studies lack a near application in disease control such as vaccines or antibiotics. Examples: ...
3
votes
1answer
92 views

Is it possible to insert DNA without cutting the recognition site with CRISPR/Cas9?

We are looking for a way to insert DNA into a genome, but we would like to do it in a way that the recognition site stay intact to be able to add again DNA at the same location. Do you know if it is ...
5
votes
1answer
105 views

Doubt on genomic code for nucleosome positioning?

I was reading "A genomic code for nucleosome positioning" (by Eran Segal et al). And I am having 2 doubts. The figure(b) in this image from the paper shows the graph of fraction (3-bp moving average)...
4
votes
1answer
150 views

DNA sequencing problem

First off, let me start by outlining the problem: Your laboratory has established a technique for examining DNA replication in a cellular extract. To the cellular protein extract, you add nucleotides,...
5
votes
1answer
147 views

Can human mRNA be translated in vitro by prokaryotes?

As the genetic code is universal, can mRNA from a human cell be correctly translated by a prokaryote in a in vitro translation system?
2
votes
1answer
127 views

How does alternative splicing work?

I am trying to find out what controls what exons are spliced out, and I keep coming across the term cis regulator, but I cannot seem to find a clear explanation of what happens... Thank you in ...
2
votes
1answer
830 views

What are microRNA, siRNA and antisense RNA?

From what I understand, microRNA binds to proteins which can cut certain mRNA strands do that this protein is not synthesised. This seems like gene silencing to me, however I have also come across the ...
1
vote
1answer
31 views

RNA-Polymerase III transcribed genes

I have a list of differentially regulated genes from a high-throughput experiment of the human genome. I would like to find out which of these genes are transcribed by a RNA polymerase III and which ...
4
votes
2answers
3k views

What's a protein pulldown assay?

I'm reading a paper and the authors mention a "protein pulldown" assay. I've never done this before, and googling doesn't bring up much. Could I get a rundown of the basic theory behind it? Also ...
1
vote
1answer
50 views

What are the roles of cadherins in epithelial mesenchymal transitions? [closed]

I know that cadherins control the expression of cancer cells involved in the epithelial-mesenchymal transitions, but I was wondering exactly how the process worked.
2
votes
1answer
270 views

Relationship between leaf structure and Photosynthesis rate

We can see numerous leaf structures in plant kingdom. As the leaves are designed for photosynthesis, their structure must be a factor for any optimization in photosynthesis or chlorophyll distribution....
4
votes
1answer
191 views

Nomenclature of genes and proteins

With respect to this paper: Identification of Host Proteins Required for HIV Infection Through a Functional Genomic Screen In the abstract, I found names such as Rab6 and Vps35 and TNPO3. So Rab6 ...
3
votes
1answer
56 views

Introducing novel genes to an adult multicellular organism?

Is it possible to introduce a novel gene into the genome of every cell (or at least most cells) of an adult multicellular organism? How would this be done? Thanks, CDB
1
vote
1answer
124 views

What, if any, diseases do larder beetles carry?

I found one of these beetles on my bed as I was attempting to get in. I'm 80% sure my cat carried it in (I found it in the exact same space he had been sitting ten minutes previously). My question is ...
2
votes
1answer
49 views

Can anyone identify this mystery caterpillar?

I found this caterpillar in in El Cerrito, CA and was wondering what kind it is?
1
vote
1answer
40 views

Enzyme\Protein amounts in cancer

I am searching for source, that providing information about enzymes\proteins, in different types of cancers, that their amount in cell is significantly higher - comparing to normal, healthy cell. ...
7
votes
1answer
974 views

Why are there no known photosynthetic archaea?

I'm taking a microbial physiology course and we noted that, while some archaea are phototrophic, there are no known photosynethetic archaea. Are there any physiological characteristics that make ...
2
votes
2answers
327 views

Is it possible to train allergic resistance by exposing yourself to allergens?

My hypothesis is that one can decrease the allergic reactions over time by continuously exposing yourself to slowly increasing doses of allergens. Is there any scientific evidence pointing this right ...
23
votes
3answers
4k views

Do all organisms have to die?

I understand (a little) that there are biological clocks and reason that after a certain amount of time organisms die. I'm wondering if that is something inherent in our DNA or in biology/chemistry in ...
2
votes
1answer
92 views

Is Norway spruce (Picea abies (L.) Karst.) isohydric or anisohydric species?

Question from a thesis defense list ask me this. But I can't find the exact answer on the internet or in books. In my thesis, I described isohydric plants, for example maize, lupin, pea, poplar. This ...
6
votes
1answer
860 views

Are gene variants at different loci also called alleles?

I think the title says it. I always read that alleles are gene variants at a given locus, which confuses me. Thanks!
2
votes
1answer
91 views

Monochromator in fluorescence microscopy [closed]

I'd like to ask why are there no fluorescence microscopes that use a monochromator instead of filters? If there are any, then I should change my question as, which ones use it and why are they so ...
1
vote
1answer
65 views

What is the minimum functional biological light sensor? [closed]

As a follow up to this question regarding the evolution of the eye, it was suggested that primitive eyes only needed to evolve a light sensor and could perhaps use the existing biochemical cascade ...
5
votes
1answer
65 views

Is it possible to isolate and analyse intermediates of protein folding?

I would like to know if there is an assay which could allow us to analyse a protein before it has assumed its 3D functional form. While studying structural biology, I only came to know the forces that ...
6
votes
1answer
216 views

Why do some bacteria have most genes on the leading strand of the genome?

Genes in the (+) strand are black and genes in the (-)strand are red. The gene distribution in E. coli genome is somewhat expected: transcribed regions would tend to alternate with non transcribed ...
1
vote
2answers
179 views

Why do insects avoid being on their back?

I have noticed that when insects are placed on their backs, they tend to turn themselves over quickly or else appear to be in distress. Is there a physiologic, anatomic, or adaptive reason why supine ...
1
vote
0answers
43 views

Why do restriction-modification systems work?

Some RM systems (restriction-modification systems) are plasmid-borne and are transferred through bacterial conjugation. As you all know, there are two genes in an RM system, the gene that codes for ...
8
votes
1answer
124 views

Genotype to phenotype map and the G-matrix

Suppose I have a genotype-phenotype map defined by the matrix $\mathbf{Z}$:         The scalars $G,P$ represent the number of genotypes and traits, respectively. ...
2
votes
0answers
268 views

Reason for different color perception in left/right eyes?

What could be the reason for a difference in color perception between the two eyes of an adult individual without any known eye conditions? In particular, a difference in the perceived color ...
11
votes
3answers
679 views

Do other animals have different blood types?

Humans have the ABO and Rhesus blood typing systems. I have two questions about it: Why have we evolved these blood types? Do other animals have different blood types as well?
2
votes
1answer
54 views

Why is an increase in the amount of oxygen in the atmosphere favorable for life?

I have followed the David Attenborough series on 'First life' and heard, that an increase in the amount of oxygen in the atmosphere, as it took place just before the Cambrium, is generally favorable ...
4
votes
1answer
345 views

What do trans-fats do when in human body?

Trans fats cause health problems, especially to the heart. https://en.wikipedia.org/wiki/Trans_fat#Health_risks My guess is that all effects happen because trans-fats are inherently toxic as the ...
8
votes
2answers
566 views

Reasons why living fossils exist?

A living fossil is a living species (or clade) that appears to be similar to another species otherwise known only from fossils, typically with no close living relatives. A living fossil is ...
2
votes
0answers
59 views

What is NK-cell compartments?

with respect to the paper: Adaptive reconfiguration of the human NK-cell compartment in response to cytomegalovirus: A different perspective of the host-pathogen interaction What is meant by NK-...
3
votes
2answers
200 views

What proves that speciation is a pairwise process? [duplicate]

I have been asked this questions by many biology students and even non-biologist without a pretty straightforward answer to give. We are quite accustomed to phylogenetic trees where a common ancestor ...
1
vote
0answers
68 views

Why is amyloplast produced by some plant cells but not other cells?

For example I know it is produced in Potato's and fruits and its purpose is to synthesize glucose in to starch through polymerization. But why is it only present in some cells? Is it only present in ...
5
votes
1answer
76 views

How does de-myelination occur in multiple sclerosis?

From what I understand, only the oligodendrocytes are affected in multiple sclerosis, and they are attacked by T cells which cross the blood-brain barrier. This leads me to two questions: How is the ...
3
votes
2answers
47 views

enhancers in cell-type-specific signatures

I was reading an article in nature : Epigenomics: Roadmap for regulation and was confused by the definition or/and interpretation of enhancers. Enhancers are activated through interactions with ...
6
votes
3answers
269 views

Proteins folding

Some of us are involved in the folding@home project, spending time, money and resources. I would like to know an answer to two main questions: how do we know we fold it right? I mean these models ...
2
votes
1answer
85 views

Protein PTM site prediction

Is there any in silico analysis method to predict post-translational modification sites on a given protein?
2
votes
0answers
55 views

How do parrots stabilize their field of view without moving their necks while walking?

Based on my search online, I have found some theories which try to validate the activity of some birds (like pigeons) which involves moving their heads and neck while walking. These theories include - ...
1
vote
0answers
39 views

Which data format for mRNA expression matrix is necessary to run pathway analysis with Paradigm?

I am running Paradigm on a matrix of mRNA expression. I read Vaske, Charles J., et al. "Inference of patient-specific pathway activities from multi-dimensional cancer genomics data using PARADIGM....
1
vote
0answers
24 views

Can medications or drugs damage oocytes? [closed]

Some drugs are teratogens, but can any drugs cause DNA damage to oocytes before ovulation or conception (eg chemotherapy drugs)?
8
votes
1answer
242 views

What is the mechanism behind tinnitus?

I seem to have come across two contrasting explanations for tinnitus induced by loud noises- i.e. damage to the hair cells in the cochlea. On the one hand, I have read that damage to the hair cells ...

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