The study of chemistry within the scope of biology: the compounds that occur and the reactions involving them in living organisms.

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12
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2answers
363 views

Are there any plants that fix their own nitrogen?

I know that most nitrogen is fixed through industrial processes and bacterial symbiotic relationships. However, are there any plants that can fix their own atmospheric nitrogen?
8
votes
3answers
214 views

Can elements of one's environment act directly as hormones?

Can pollution and things in an organism's environment serve as hormones?
44
votes
4answers
6k views

Why 22 amino acids instead of 64?

This question got me thinking about amino acids and the ambiguity in the genetic code. With 4 nucleotides in RNA and 3 per codon, there are 64 codons. However, these 64 codons only code for 22 ...
33
votes
5answers
1k views

Human perception of time depending on age

From what I can tell and what thus far all people with whom I discussed this subject confirmed is that time appears to "accelerate" as we age. Digging a little, most explanations I found basically ...
20
votes
1answer
511 views

How, on a physical level, does ATP confer energy?

When ATP is used as the energy currency to make, say, reaction X + Y → Z happen, is what happens on a physical level down at the molecular scale that during the reaction ATP + H2O → ADP + Pi ...
8
votes
3answers
490 views

What triggers meiosis in gonadal cells?

What specific biochemical processes are involved in inducing meiosis rather than mitosis? Why are gonadal cells the only cells in the human body which do undergo meiosis?
10
votes
1answer
350 views

What is the functional and structural distinction between core (H2A, H2B, H3,H4) and linker(H1/H5) histones?

Many explanations of histone biochemistry isn't quite elucidating for the undergraduate student. How does histone structure (dimers, octomers) relate to their specific functions as core or linker ...
22
votes
4answers
4k views

What does the human body use oxygen for besides the final electron acceptor in the electron transport chain?

My biology teachers never explained why animals need to breathe oxygen, just that we organisms die if we don't get oxygen for too long. Maybe one of them happened to mention that its used to make ATP. ...
17
votes
2answers
4k views

What is the mechanism behind “acquired” alcohol tolerance?

I can understand natural variation in alcohol dehydrogenase (ADH) in a population leading to variation in rate of inebriation (after controlling for other variables -- e.g., mass, food consumption, ...
8
votes
1answer
90 views

What are the variables that control/influence the color of oranges(Citrus sinensis)?

I hear that Oranges cultivated in tropical areas of the world tend to be greener when ripe, is that correct? Even the same type of Orange differs in color if cultivated in California or Florida. I ...
32
votes
4answers
1k views

Can scientists create totally synthetic life?

This particular question has been of a great deal of interest to me, especially since it dives at the heart of abiogenesis.
13
votes
1answer
8k views

What effect has changing pH and salt concentration on protein complexes?

I'm struggling to find peer reviewed literature that explains the effect of changing the pH and the salt concentration on protein/protein complexes in solution. What effect does the pH and the salt ...
13
votes
3answers
1k views

What implications has the missing 2'-OH on the capability of DNA to form 3D structures?

The chemical difference between RNA and DNA is the missing 2'-hydroxyl group in the nucleotides that build DNA. The major effect of that change that I know of is the higher stability of DNA compared ...
7
votes
2answers
469 views

How can I measure bacterial alkaline phosphatase activity?

I want to measure alkaline phosphatase activity using PNPP in my mutant bacteria strains, but all the protocols I found involve purification of the phosphatase (which I have no need of). Does anyone ...
50
votes
3answers
27k views

Why is uracil used in RNA rather than thymine?

What is the advantage gained by the substitution of thymine with uracil? I have read previously that it is due to thymine being "better protected" and therefore more suited to the storage role of ...
17
votes
1answer
603 views

Can siRNA induce DNA methylation in mammalian cells?

Some years ago Hiroaki Kawasaki and Kazunari Taira published an article called "Induction of DNA methylation and gene silencing by short interfering RNAs in human cells" in Nature: In plants, ...
10
votes
1answer
260 views

What are the olfactory chemicals in whiteboard/permanent markers and what do they bind to in the nose, lungs, and brain?

What are the olfactory chemicals in whiteboard/permanent markers and what do they bind to in the nose, lungs, and brain?
7
votes
4answers
158 views

How can I produce milligram quantities of an isotope-labeled DNA oligomer?

I'd like to produce a specific DNA sequence on a milligram-scale and 13C15N-label it. The sequence is around 35 nucleotides long, so chemical synthesis is out due to the exorbitant costs. I'm also ...
10
votes
2answers
261 views

Which sequence characteristics influence the transcription efficiency of T7 polymerase?

The T7 polymerase doesn't transcribe all sequences equally well, the transciption efficiency can vary widely for different sequences. One well known requirement of the T7 polymerase is that the ...
11
votes
1answer
693 views

What limits the maximum spacing of Nodes of Ranvier and which organisms tend to have the widest gaps?

Assuming that a longer distance between gaps in the myelin sheath is beneficial for an organism due to the increased propagation speed, what is the limiting factor in determining the maximum spacing ...
9
votes
4answers
207 views

How can I avoid digesting protein-bound DNA?

I'm interested in sequencing and analyzing the bound DNA, and minimizing the amount of unbound DNA that gets sequenced through digestion. When digesting protein-bound DNA, is all of the unbound DNA ...
18
votes
3answers
781 views

How is RNAse contamination in RNA based experiments prevented?

Does anyone have any suggestions to prevent RNAse contamination when working with RNA? I tend to have issues with degradation regardless of whether I use DEPC treated / RNAse free water and filtered ...