The scientific study of chemical processes in living organisms, including, but not limited to, living matter.

learn more… | top users | synonyms

5
votes
2answers
46 views

Does vinegar neutralize the strongly basic compounds in cement?

I have heard that washing one's hands with vinegar is effective in neutralizing the strong bases in cement and is more effective than water. I want to know how cement burns and what bases are ...
0
votes
0answers
13 views

What happen when there is no salt bridge in microbial fuel cell?

I wonder if there is no salt bridge on microbial fuel cell, Are there have the same amount of current or none?
1
vote
1answer
49 views

Greater entropy: an atom or macromolecule?

A question that appeared on my last chemistry exam was : Which of the following has greater entropy A) An atom B) A macromolecule The question doesn't specify anything else(i.e. type/size ...
2
votes
1answer
22 views

Quaternary ammonium anti-microbials

Also good against fungi, amoeba, and enveloped viruses,[7] quats are believed to act by disrupting the cell membrane. Quaternary ammonium cleaners have long-alkyl substituent chains. Why is this ...
3
votes
0answers
71 views

What is the mechanism of monofunctional glycosylase catalysis? [closed]

I am learning about base excision repair mechanisms. I understand the main idea how glycosylases are working, but I am trying to understand this in much more detail. I found a paper where they have ...
1
vote
1answer
32 views

Is Chemical Engineering a good pathway to Biomedical Engineering for graduate school? [closed]

I have been thinking about my future goals and I have recently decided to go for Biomedical Engineering. sites recommend to start in Chemical Engineering because its a good pathway for biomedical ...
2
votes
2answers
18 views

What is the difference between protein domains, motifs, and supersecondary structures?

I was just wondering if there is any difference between supersecondary structure and motifs. As well, is a protein domain an independently folded region of a protein that has a particular function ...
5
votes
2answers
62 views

What is the active ingredient in this “stimulant?”

It is an easily defensible argument that this is a medical question rather than a chemistry one, however, I feel that it leans ever so slightly towards chemistry, and so I posted it here. There is a ...
2
votes
1answer
46 views

Human Body and RNA/DNA

After research I found that enzymes are responsible for metabolism, specifically catabolism and anabolism. This in turn creates the necessary chemicals in your body. The only question left is: what ...
1
vote
1answer
45 views

Units for dissociation constant and relationship to Gibbs Free Energy

How does one "convert" between an equilibrium constant calculated from the Gibbs free energy for a dissociation reaction and experimentally determined dissociation constants? $$ \Delta ...
3
votes
0answers
19 views

How is chlorophyll made in plants?

I've been studying photosynthesis and something made me think about how chlorophyll itself is made in plants.How exactly is it formed ?
1
vote
2answers
107 views

Basic chemistry of the Shinoda test for flavonoids?

In this test, four pieces of magnesium fillings (ribbon) are added to the ethanolic extract followed by a few drops of concentrated hydrochloric acid. A reddish colour indicates the presence of ...
0
votes
0answers
12 views

Simulating enzymatic change rates of Carbonic anhydrase

I'm trying to simulate effects of carbonic anhydrase on cellular pH as caused by changes in bicarbonate. I assume a bicarbonate homeostatic mechanisms which replenishes intracellular conenctrations ...
2
votes
1answer
43 views

What does the adenosine do in ATP?

This is an extremely basic question about biochemistry from someone who doesn't know much about organic chemistry. I'm aware of how organisms store energy ATP and release it by dephosphorylating it ...
1
vote
0answers
39 views

How can i detect Formalin in food easily

I am trying to detect formalin in different types of food. Formalin $(\ce{CH2(OH)2})$is an aqueous solution of formaldehyde, which is $\ce{CH2O}$ or $\ce{H2CO}$. I used many chemicals to do this, but ...
3
votes
0answers
62 views

How is Melatonin Synthesised?

I should like to know roughly how the hormone melotonin is synthetically made for the pharmaceutical industry (i.e. not how it is made in living beings). I can't seem to find any reference to its ...
0
votes
0answers
3 views

How do I go about calculating protein concentration to make a set of protein standards for protein quantification via dot blot?

I have been given a protein of unknown concentration and have been asked to make a set of standards using a protein with a known concentration so we can quantify roughly via dot blot. I need to know ...
1
vote
0answers
55 views

Lewis Acidity and Bacteria

How does Lewis acidity correlate with bactericidal activity? I read on Wikipedia that the two are positively correlated but no explanation was given. Does it have to do with the movement of ...
1
vote
1answer
44 views

(+)-Bicuculline, what does (+) mean?

I was looking up some ion channel blockers. What does (+) or (-) below mean? (+)-Bicuculline (-)-Bicuculline methiodide
1
vote
1answer
28 views

Decrease of Bicarbonate to compensate Respiratory alkalosis

I am studying this claim Compensatory mechanism in respiratory alkalosis is decrease of SB i.e. bicarbonate ions ($\ce{HCO3^-}$). There are reactions $\ce{HCO3- \rightarrow H+ + CO3^{2-}}$ ...
2
votes
1answer
26 views

Atomic coordinates for DNA bases as they appear in a B-form or A-form duplex

Where can I find atomic coordinates for guanosine / cytosine / thymine / adenine (either the ribonucleotide or deoxyribonucleotide bases) where the atoms are configured in the manner we would expect ...
0
votes
1answer
31 views

Test for gluten?

I have searched online for 'chemical tests for gluten'; however all the results are about 'home testing kits' (presumably for people with a gluten intolerance). I would like to know if there is a test ...
2
votes
1answer
34 views

What in general will determine whether a chemical reaction will occur? [closed]

This probably is (too) huge a question, just like Is there a general way to predict products of a chemical reaction. However, it is still a valid question to ask, given that its sister (or mother) ...
0
votes
1answer
29 views

How is Humic substance destroyed in nature?

Humic substance consists of many, to my knowledge poorly understood, species of organic matter, mostly carbohydrates chained in intersting (and also poorly understood) ways. Humic substance is an ...
0
votes
0answers
19 views

Does Bioglass 45S5 attach to enamel?

When I search, I see bioglass binds to bone and dentin, but nothing is said about enamel. The bioglass allows the creation of a hydroxyapatite, and from what I've read I think enamel is ...
0
votes
2answers
47 views

Is photosynthesis endothermic and exothermic at the same time? … somehow?

Photosynthesis is obviously an endothermic reaction, I mean, what would be the point otherwise, right? This is probably just sheer and utter stupidity on my behalf, but why does Wikipedia say the heat ...
0
votes
1answer
53 views

Test for glyphosate in water, boolean style

Testing for contamination of the ever so popular glyphosate based herbicide "Roundup" in water is a service that many labs provide, one of them is the Microbe Inotec Laboratory . They use an enzyme to ...
0
votes
0answers
112 views

pH of amino acid solutions

Hi may someone help me with this question A glycine ($\ce{NH2CH2COOH}$) is a standard amino acid with two $\text{p}K_{a}$ ($\text{p}K_{1}=2.0$ for $\ce{-COOH}$ and $\text{p}K_{2}=10.0$ for ...
2
votes
1answer
76 views

Ratio of conjugate bases of a tricarboxylic acid

Hi does anyone know how to solve this question? A tricarboxylic acid $\ce{H3A}$ has three different types of $\text{p}K_\text{a}$ $(\text{p}K_\text{a, 1} =2.0,$ $\text{p}K_\text{a, 2}=5.0,$ ...
4
votes
1answer
71 views

Deriving goldman equation

So I've been trying to follow the derivation of the Goldman-Hodgkin-Katz equation on Wikipedia (https://en.wikipedia.org/w/index.php?title=Goldman_equation ) - I can follow it through after it sets up ...
2
votes
2answers
144 views

Which branches of chemistry and in what order to learn (self study)?

Hi I have decided to give chemistry another shot (it didn't take so well way back in high school). My main interest is for reading up on brain chemistry and pharmacology. I currently have a textbook ...
1
vote
1answer
138 views

A Material that sticks to the skin, without adhesives!

I am onto a project for making knee braces for female anatomy, and I have been looking for a material, that i could line the pads with, that would stick to the skin of the players and still provide ...
1
vote
1answer
67 views

Concentration from Absorbance vs Time

I am given a protein, BAPNA, and the initial concentration of the protein. The experiment involves reaction rates of varying protein concentrations. Each sample cuvette is inserted into a ...
22
votes
5answers
5k views

Does water really 'go bad' after a couple of days?

Among my friends it is a sort of 'common wisdom' that you should throw away water after a couple of days if it was taken from the tap and stored in a bottle outside the fridge, because it has 'gone ...
4
votes
1answer
44 views

What is “stuffy”/“stale” air composed of?

When a room is not ventilated for a long time (days if people are present, weeks if not), humans perceive a change in air quality commonly described as "stale" or "stuffy" air. What is going on here ...
2
votes
1answer
99 views

Products of the o-Toluidine oxidation with glucose oxidase and peroxidase

Could anybody describe which product is formed in the following reaction (o-Toluidine oxidation)? $$\ce{H2O2 + o-Toluidine_{uncolored} - Peroxidase -> H2O + 1/2 O2 + o-Toluidine\; ...
3
votes
1answer
329 views

Gold's atomic structure and bonding in relation to the separation techniques used

How is Gold's atomic structure and bonding related to the separation techniques used to distinguish it from other substances? I'm just confused on what I'm actually searching for, I have read so ...
3
votes
1answer
87 views

Biochemistry for a mathematics student?

I am a second year mathematics student. I am mostly interested in statistics. Right now my curriculum doesn't offer me much choice (all second year courses are mandatory) but next semester I will be ...
4
votes
1answer
105 views

Spectrophotometric assay by pNPP

Here is a series of related questions that I want to ask. If you think they ought to be different questions, please tell me so. Background The activity of acid phosphatase is measured by an ...
6
votes
1answer
65 views

Can I damage a biotinylated antibody in solution by vortexing or mixing too vigorously?

I am running an immunoassay using biotinylated antibodies and have noticed a decreasing trend from duplicate assay runs (completed within minutes of eachother) from the same vial. In between each ...
4
votes
2answers
98 views

Can luciferin + ATP → luciferyl adenylate + PPi be reversed?

Reading about the light emitting reaction of luciferin + ATP, catalysed by luciferase I am confused about the following. On this webpage the partial formula is written as: luciferin + ATP → ...
0
votes
2answers
47 views

Using Spectrophotometer to analyse enzyme reaction

Suppose we have two enzymes with concentration of 1X and 0.1X We then add a substrate and incubate the mixture for 1 or 10 or 20 minutes.( So,there will be total of six samples.) Question ...
2
votes
1answer
142 views

Help with synthesis flowchart, please

This is for a homework assignment, I'm usually very good with reactions and am really disappointed after getting it wrong four times, where did I go wrong?
1
vote
1answer
44 views

Photosynthetic rate calculation

What are the steps in calculating the photosynthetic rate ($\mu\text{mole}\ce{O2}/$ $\text{m}^2 / \text{min}$) for a leaf that has an area of $0.0025 \text{m}^2$ and a $\ce{O2}$ evolution rate ...
3
votes
2answers
249 views

Peptide sequencing problem:

A nonapeptide was divided into three samples and each sample was subjected to cyanogen bromide, chymotrypsin, or trypsin. The fragments obtained in each of the treatments were separated, hydrolyzed ...
2
votes
0answers
28 views

Can TBE electrophoresis buffer be stored in a PETE container?

I'm doing a science project on agarose gel electrophoresis and would like to know if it is safe to store Tris/Borate/EDTA buffer solution inside a PETE container since I will be making about 10L of ...
8
votes
3answers
119 views

Would it be possible to produce a non-toxic atmosphere using a coal fire and frozen oxygen?

A Pail of Air is a classic science fiction short story by Fritz Leiber from 1951 describing how a family survives on an Earth that has left its orbit around the sun, using desparate low-tech methods: ...
1
vote
2answers
60 views

Explaining the reaction

i am an immunology master student without prior knowledge of biochemistry. Could someone explain me this 6 reactions ? I could learn the reactions by heart. But i want to understand, why exactly the ...
2
votes
1answer
37 views

Question concerning the scaling for % completion time in a Michaelis–Menten scenario as a function of substrate concentration

Say I have a straightforward Michaelis-Menten reaction where an enzyme $E$ at some fixed concentration $[E]$ forms an interaction complex $ES$ with a substrate $S$ (with initial concentration ...
8
votes
1answer
105 views

What molecular features create the sensation of sweetness?

There are many compounds that taste sweet. Many of the artificial ones taste much sweeter than natural sugars (which is why they contribute little to energy intake when use as sweeteners). A range ...