1
vote
1answer
151 views

Does DNA Ligase look for complementarity in sticky ends?

Can DNA ligase seal two non-complementary sticky ends if the reaction is incubated at the optimum conditions ? I do almost 100% double digestion in the lab. However, during ligation, when I do a ...
6
votes
1answer
528 views

Relationship between nerves and axons

I just wanted to get a realistic viewpoint of our nervous system. I understand arteries and veins, but I wanted to know how similar our nervous system is to that? I understand we have neurons (...
5
votes
1answer
2k views

How does food intake affect medicine? Why pill instructions recommends taking them before (after) meal?

Even simple vitamins seem to have this in the instruction. Why is is so? Is there some simple model of how do pills interact with food? Does it depend on the food type? (What about drinks?) Should ...
1
vote
0answers
662 views

Why do plants produce so much more sugar than they use?

I recently asked the question, "Do plants need O2 to consume energy they've stored via sugar?" to which @canadianer responded, "Yes, plants require oxygen to generate ATP from sugar. However, they ...
0
votes
1answer
40 views

Do plants need O₂ to consume energy they've stored via sugar?

This question came up as I work my way through the answers to another question I just asked. My understanding is that plant photosynthesis looks something like this (though with lots more going on ...
2
votes
2answers
105 views

Protein Structure Parameters

I'm wondering about the minimal set of parameters necessary to define a protein's structure. My understanding is that the backbone geometry is defined by the phi and psi angles (torsion angles), and ...
2
votes
1answer
39 views

Could someone entirely absorb smells by smelling?

When smelling, your nose detects the smells by absorbing them. Does this mean that, if you were in an enclosed space, you could smell so much all the smell goes, and there is none of that molecule ...
2
votes
1answer
276 views

Proteins: Post translational modification

I am a physicist and trying to understand some protein chemistry for a small project. Basically, amino acids combine to form proteins and after forming the primary structure, some chemical ...
1
vote
0answers
89 views

Does Smartphone cause ear pain? [closed]

I used samsung galaxy y for last two years. I used to speak more than 3 hours per day in the phone. Now if i bring any smart phones near to my ear, i can't bear the pain. I have little cold and 4 ...
4
votes
1answer
492 views

How much of what we eat ends up in the toilet?

An awkward question. Bear with me... In terms of mass, what percentage of the food that we eat do we end up excreting? Of course, it depends on a whole host of factors so lets assume a healthy ...
4
votes
1answer
441 views

Redheads and pain receptors

I remember reading this in a biology textbook, and decided to do a little digging. Redheads have a lower sensitivity to some pain and a higher sensitivity to other compared to people of other colored ...
2
votes
1answer
52 views

In insects, does the Alanine repeat occur on the homeodomain sequence of the abdomen or does it occur on a different sequence?

By "Alanine repeat", I am referring to the suppression of the formation of extra insect legs due to Ubx gene suppression through Distal-less repression.
4
votes
2answers
99 views

How does it make thermodynamic sense for photosynthesizers to turn CO₂ into O₂?

My understanding is that animal metabolism consists of exothermic reactions like $$\ce{C6H12O6 + 6 O2 ->6 CO2 + 6 H2O + energy}$$ This makes thermodynamic sense to me. Animals need an exothermic ...
6
votes
4answers
145 views

Enzymatic error rate

I am aware that each enzyme generate a certain amount of misproducts. This is well documented, for example, for the DNA polymerase. I am interested in enzyme involved in biochemical processes, so for ...
7
votes
2answers
183 views

Why did the Brain develop in the front in most organisms?

I was wondering: why most, well, pretty much all organism with a brain have it right in front of their bodies or at the top.
3
votes
0answers
87 views

What's Incomplete atrioventricular heart block (AV)? [closed]

This is unclear for me and I can not understand differences between complete and incomplete atrioventricular heart block.also I want an electrocardiograph of incomplete atrioventricular heart block.
14
votes
2answers
8k views

Why do we urinate more when we are nervous?

This question is a result of my personal experience... But I guess that is common for many of us. My school timing is 8:00 am to 1:30 pm (usually). During normal school days I typically urinate one ...
6
votes
1answer
1k views

Which will produce more oxygen? Less number of (larger) trees or more number of (smaller) plants?

In a given area A, we have two choices - (i) we can plant maximum number of trees (which are larger in size) possible in A, say m OR (ii) we can plant maximum number of plants (which are smaller in ...
0
votes
0answers
27 views

Stem cells and if they can correct a lack of apoptosis

If a cell ,call it C1 has no functioning apoptosis mechanism could a stem cell somehow be 'induced' to be like C1 , at least have the same genome as C1. Then use this stem cell 'duplicate' to 'restart'...
2
votes
0answers
77 views

Which method would more accurately help to identify the unknown concentration of a protein sample between the A280 and the Bradford methods?

I quantified my protein using the standard Bradford method and the A280 methods and obtained values that were far off from the theoretical value of the protein of interest, and therefore was wondering ...
6
votes
1answer
1k views

Time lapse between fresh blood's exposure to air and that same blood turning darker red-brown

For investigative purposes, I'm searching for a tool that can be used as a quick visual assessment of the the length of time that blood has been exposed to air after the blood flow has stopped.. Let's ...
4
votes
1answer
359 views

How does aging affect fingerprint?

Do fingerprints change as we grow from child to adult? Most notably, what is the effect of the increase in surface area of palms and fingers on the finger print? Does the finger print simply increases ...
3
votes
0answers
196 views

Why are fingerprints different even in identical twins? [duplicate]

Why are fingerprints different from person to person? It can't be genetics. Even identical twins has different sets of fingerprints. What is the deciding factor that form and shape our fingerprints?
6
votes
1answer
227 views

Is brain transplantation possible?

Many organs can be transplanted nowadays, including the liver, lungs and kidneys. Can the brain be transplanted?
2
votes
1answer
65 views

Metabolism of different saccharides

Learning about carbohydrates, I wonder what the differences there are in terms of metabolism, and overall health between the different types of saccharides. In other words, does the body use ...
6
votes
3answers
123 views

Do variant callers miss rare variants in reference?

Generally variant calling programs (such as GATK-UnifiedGenotyper) look for differences between reference genome and submitted sequence. However, we all know that reference genome consist rare ...
1
vote
3answers
45 views

How do scientists decide which version of a polymorphism is the main one?

This in fact has bugged me for years, but now I finally remembered to ask. I suppose that if one variation is more frequent, it can be labeled as the default, but what about variations that are ...
2
votes
0answers
37 views

Neural correlates of the function of the cardiovascular system?

Are there any known neural correlates of the function of the cardiovascular system? I'm looking for research results that use standard brain imaging techniques (e.g. electroencephalography, ...
3
votes
1answer
195 views

Maximum RPM in zero-g before losing consciousness, spinning head-over-heels

There are more than a few scenes in Gravity that I find dubious. Specifically the ones where people are revolving very quickly, either about their own center of gravity or at the end of a rather long ...
9
votes
2answers
114 views

How well does the radius of a tree correlate with its age?

I'm looking for a cheap non-invasive ways to approximate the age of a tree (a birch). Measuring the radius pops up in the mind as the first alternative. How would one do that? Measure at multiple ...
2
votes
0answers
24 views

What mechanism is responsible for germinating in the right direction (root towards gravity)? [duplicate]

Regardless of the initial seed orientation, the root always grows/sprouts/germinates "towards gravity" (see picture), sometimes curving around in sharp 180°. What is the mechanism responsible for ...
2
votes
0answers
44 views

Protein Design - Target Structure Specification

I'm curious about how protein structures are defined in general, but in particular, I'm wondering how a target structure can be specified without knowing the amino acid sequence. For example, in ...
2
votes
2answers
126 views

DNA barcoding and real-time PCR

I recently read an article on how DNA barcoding was used to identify species present in health products. I also read an article about how Real-Time PCR was used to identify meat species in meat ...
2
votes
1answer
156 views

Biphasic T wave caused by digitalis toxicity

Digitalis is a drug that can be used during coronary insufficiency to increase the strength of cardiac muscle contraction. But when overdosages of digitalis are given, depolarization duration in ...
4
votes
1answer
197 views

What actually are thoughts? [closed]

The human brain consists of neurons that transmit impulses like wires that conduct electricity.I am confused about where are our thoughts stored and what really are thoughts? For example if I think ...
2
votes
1answer
2k views

What happens to our umbilical cord internally as we age?

I was always curious as to if or how much of the internal structure or workings of the umbilical cord are still in existence as we age. What happens to it over time? The wikipedia article naval ...
11
votes
3answers
984 views

Do humans perceive temperature or heat-flux? (or both?)

The general understanding is that when I touch an object, I perceive its (relative) temperature. A metal object at room temperature, however, will often feel cool to the touch. This leads me to ...
3
votes
1answer
109 views

Why oxLDL accumulate to form foam cells?

In atherosclerosis, why macrophage store all the cholesterol from oxLDL inside, and turns to foam cell, and not just degrade it and going back to blood? (there are some amount that leave the plaque, ...
5
votes
1answer
99 views

Can we artificially increase human growth using HGH?

Robert Pershing Wadlow was a man who lived in the first half of the twentieth century. He had hyperplasia of his pituitary gland, which caused him over-produce human growth hormone (HGH), and as a ...
14
votes
1answer
1k views

What is the most condensed form of (stored) energy used in biology?

When considering how organisms store energy for later use, I was wondering what substance known in Biology is best for compacting the most energy in the smallest space(volume-wise). With my (limited) ...
1
vote
0answers
24 views

Clumping factor test

I'm come across this question and I'm somewhat confused: In the test for staphylococci, the clumping factor detects: staphylothrombin DNase mannitol fermentation Fimbriae fibrinogen-binding protein ...
1
vote
1answer
138 views

Why is pericardium muscle repolarizated earlier than endocardium? [closed]

I was reading about heat muscle contraction and I read: The endocardium depolarization happens earlier than pericardium , but pericarduim repolarization happens earlier, therefore the T wave in ...
5
votes
2answers
193 views

Where can I find mutation datasets for cancer?

My lab has been using TCGA data (somatic mutations and clinical data) to develop panels of genes and of mutations we expect to see in certain cancer populations. We'd like to validate our panels by ...
14
votes
1answer
331 views

What are the requirements for a stable carbon cycle in sealed “bottle gardens”`?

The most famous example of a sealed bottle garden is David Latimer's bottle with a Spiderworth plant, pictured below, which has been sealed for 40 years. My own attempt at a bottle garden is failing ...
4
votes
1answer
117 views

Clarification on the “orientation” of chromosomal rearrangements

I need some clarifications on the concept of "orientation" in case of chromosomal rearrangements. Given a deletion event on a chromosome for example, is the resulting DNA at the breakpoint always in ...
4
votes
1answer
127 views

Visualising a subset of the tree of life

I understand that many curated trees of life already exist (eg http://tolweb.org/tree/) but is there any website that allows one to input a list of organisms, and then produce the current best guess ...
1
vote
1answer
909 views

What is the present tense verb form of apoptosis?

For example, if I want to say something along the lines of "this signaling pathway causes a cell to go through the process of apoptosis", but I want to shorten the phrase "go through the process of ...
2
votes
0answers
634 views

How can the directionality of a protein structure be defined?

For a DNA molecule, you can define directionality using the convention of a 5'-3' direction on the Sense strand. However, using an N to C convention for a protein doesn't work since the ends may be on ...
4
votes
1answer
131 views

How can a drone be male?

A drone bee is male and is the product of only a queen bee. How is it that the drone bee can be male. I know that a drone is produced by an unfertilized egg, but this does not explain where the two X ...
3
votes
1answer
44 views

Are some virus loads introduced to human cell but never triggered?

Is there a term or any evidence of phage DNA integrating into chromosomes/ DNA but never being triggered? For example, could a virus that affected Neanderthals still infect human cells today but is ...

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