All Questions
Tagged with aqueous-solution biochemistry
20
questions
5
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1
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7k
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Why is copper(II) sulfate added drop by drop during the Biuret test?
The Biuret test is a test for proteins. The procedure is to add a strong base, such as NaOH, to dissolve the protein. After that, copper(II) sulfate is added drop by drop into this until a (violet) ...
- 235
3
votes
2
answers
2k
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Carbonic acid-hydrogencarbonate buffer system pH calculation?
I am learning about the pH of buffer solutions, and am slightly confused by my text book's calculation. For the blood's buffer system of carbonic acid and hydrogencarbonate ions as the conjugate case, ...
- 1,697
3
votes
1
answer
5k
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Why are different colors, according to sugar concentration observed in Benedict's test?
Colors range from green yellow orange to red. How does the sugar concentration and Cu2O concentration cause this?
I know Cu2O is red. Why is there a green or yellow color instead of just red or some ...
- 33
3
votes
1
answer
166
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Isoelectric pH of colloids?
How did we derive the relation between the isoelectric pH and the dissociation constants for the amino and carboxyl groups on zwitterionic amino acids.
$$pI=\frac {pK_{a1}+pK_{a2}}{2}$$
where $$\ce{...
- 6,795
3
votes
0
answers
633
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The Health Effects of Alkaline Ionized Water?
I came across alkaline ionized water as my aunts bought a system called Kangen Water from Enagic Inc. The water produced by this system is claimed to contain smaller water clusters (4-6 molecules) ...
- 563
2
votes
1
answer
607
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How does CO2 'dissolve' in water (or blood)?
I'm trying to understand CO2 dissolved in blood, carbonic acid and the bicarbonate ion. I think of 'dissolving' as in NaCl dissociating into Na+ and Cl- ions sloshing around in water. CO2 isn't ...
- 131
2
votes
1
answer
125
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Does CH3COOH + H2O (vinegar) lose its antibacterial and antiviral properties when exposed to air?
I have been reading about using CH3COOH + H2O (vinegar) as a mild antibacterial and antiviral agent. For example: https://pubmed.ncbi.nlm.nih.gov/15698693/
Note, before anyone gets confused (or ...
1
vote
2
answers
81
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In this specific case is the proton considered product or catalyst?
Assuming we have a reaction of
$$\ce{CO2 + H2O -> HCO3- + \color{red}{H+}}$$
then is the proton (in red) is considered a product or a catalyst?
I read the Wikipedia article titled Product (...
1
vote
3
answers
497
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Aqueous state on CO2 and O2 in the Photosynthesis Chemical Equation
While reading through a book I came across the equation for photosynthesis:
$$ \ce{6CO2(aq) + 12H2O(l) -> C6H12O6(aq) + 6O2(aq) + 6H2O(l)}\tag{1} $$ in the presence of sunlight + chlorophyll.
For ...
- 99
1
vote
3
answers
69
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When an aqueous extract of a substance is said to be administered at a certain quantity, is the quoted mass analogous to one as original substance?
I'm trying to read studies about the possible toxicity of the leaves of some plant often said to possess positive medicinal properties.
In the studies, performed on rats, it is usually said that an ...
- 147
1
vote
1
answer
77
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The time-dependent pH value in a fermentation
I want to know if someone has supporting tips or solutions to my problem:
In biotechnology, fermentations are used to grow microorganisms. These need a specific media/broth in which temperature, pH, ...
- 103
1
vote
0
answers
86
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Cationic Detergent with no odor [closed]
I am looking for a cationic detergent for a project. Unfortunately most ( or all?) cationic detergents are quaternary ammonium that smell like rotten fish or even worse
The product I am working on ...
- 2,141
1
vote
0
answers
88
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What chemicals could be added to human urine to cause harmful chemicals to precipite out?
What chemicals could be added to human urine to render it drinkable with no harmful side effects?
Urine is salty and contains other dissolved solids. Thus, drinking untreated urine would result in ...
- 147
1
vote
1
answer
8k
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I have 100 mg of a proteinase K lyophilized powder and I need to make it to a working concentration of 25 mg/mL
So I know that I need to add $4~\mathrm{mL}$ of solution to this powder, which will give me a concentration of the enzyme at $25\ \mathrm{mg/mL}$. What I do not understand is how to decide how much of ...
0
votes
2
answers
9k
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Lugol's iodine 5 % aqueous solution
There is Lugol's 5 % solution with 5 g of pure iodine and 7.5 g of potassium iodide.
In one ml there should be 12.5 mg of iodine in sum.
But there are suggestions telling that two drops of this ...
- 103