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

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15 views

What happens to the NADH produced by lactate oxidation?

I first want to note that I'm a layman attempting to gain an understanding of metabolism by reading resources on the internet with only a little understanding of chemistry. I've hit a snag: Oxidation ...
4
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1answer
32 views

Is Acrylamide carcinogenic? Why?

Recently concerned with health effects by common chemicals existent in food I've been rather busy reading article after article; and just an interesting one came around: Acrylamide (or acrylic ...
5
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1answer
42 views

Finding specific activity of an enzyme from Km values for a reversible enzyme reaction

I have an enzymatic equation in the form: $$E + S\xleftrightarrow[k_{-1} = 2.6\text{ x }10^{-2} \text{s}^{-1}]{k_1 = 3 \text{ x }10^8 \text{M}^{-1}\text{s}^{-1}} EX \xleftrightarrow[k_{-2} = ...
3
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1answer
508 views

CO poisoning - What I've been taught is a hoax?

In elementary school, I happened to ask my teacher: What is $\ce{CO}$ they talk about these days? I was then taught that Carbon monoxide "competes" with the oxygen in our blood (we were taught ...
2
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1answer
22 views

What is the mechanism by which sugars glycate proteins?

I was looking at why it's ok for glucose to circulate through the blood while fructose is prevented from doing so by the liver. Fructose glycates proteins more readily than glucose. This is the ...
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1answer
34 views

I have 100mg of a proteinase K lyophilized powder and I need to make it to a working concentration of 25mg/mL

So I know that I need to add $4~mL$ of solution to this powder, which will give me a concentration of the enzyme at $25\frac{mg}{mL}$. What I do not understand is how to decide how much of each of ...
5
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1answer
82 views

Why is the pKa (COOH) of alanine and glycine similar but the pKa (NH_3) different?

Alanine is heavier with a ($\ce{CH_3}$) than glycine which has an ($\ce{H}$). What makes them have different $pK_{a}(\ce{NH_3})(pKa: Aly=9.69 , Gly=9.60)$ but similar $pK_{a}(\ce{COOH})(pKa=2.34) $ ...
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3answers
52 views

How does photosynthesis work?

I wonder how photosynthesis works. I read the Wikipedia page, but I'm still confused. My main gap of understanding is - I assume - : I know a photon changes the velocity of an electron. But I do not ...
2
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1answer
28 views

Do molecules with carboxyl groups have properties of carboxyl's sub-functional-groups?

We're learning about functional groups of different organic molecules, and there are some I'm confused about: carboxyl, carbonyl, and hydroxyl. I was looking online but I couldn't find a direct answer ...
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3answers
151 views

Why is the units of kcat 1/s?

I understand that $k_\text{cat}$ measures the turnover number of an enzyme. This measure is therefore a quantity of molecule conversions per unit of time. I suspect that my problem is more that of a ...
2
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1answer
55 views

what would happen if you got a full package of wet silica gel on your hand after it tore open? [closed]

I accidently opened a bag of silica gel and got it on my hand what will happen to my hand because now it kinda feels weird.
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3answers
69 views

Can a single monomer be a macromolecule? If so, when?

In our science class, we're learning about the four fundamental macromolecules in every living organism: carbohydrates, proteins, lipids, and nucleic acids. Our class definition of a macromolecule ...
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0answers
38 views

resonance effect

I would need to know if there's a mesomeric effect in urea and L-citrullina molecules . Could anybody help me with this? I mean are this molecule both hybrids of resonance ? Wich are they resonance ...
0
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1answer
54 views

How does UV affect skin colors in dark-skinned people?

Skin color is one of the things one would rather not ask anything about! Only in humans, it can vary from very dark brown to pale pink. In darker-skinned people, the color is mainly due to melanin, ...
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1answer
51 views

How does Melatonin put you to sleep? How is this compound radio-protective?

Melatonin (IUPAC semi-formal name: N-acetyl-5-methoxytryptamine) is a hormone produced in humans, animals and some of plants. It's mainly famous for being the drug suggested to people with sleeping ...
2
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1answer
81 views

What compounds exist in the bitter peel of specific fruits?

Actually, my original question was: What makes a pith of pomegranate so bitter? Then I decided to be more generic. You'll hardly find someone that consumes pomegranate and doesn't nag about the bitter ...
0
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1answer
35 views

Aspartame poisoning: Can it modify aminoacids?

I just accidentally closed a webpage (and did not find it later) which described that somehow, Aspartame poisoning victims had faults in the vital proteins of their body due to the reaction of ...
13
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3answers
1k views

Why is methanol toxic?

There are two points of view for the answer of this question: The biological view, the only one that I faced during my research, states that since it can trigger perilous conditions like metabolic ...
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0answers
19 views

Finding the thermodynamics of protein unfolding from temperature and absorbance using fluorescence spectroscopy?

I recently did an experiment on protein unfolding using a Perkin Elmer fluorescence spectrometer. The protein was $\alpha$-chymotrypsin. I was given this paper for my procedure. I am now trying to ...
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0answers
7 views

Ethanol in gas & impact to old plastic motorcycle gas tanks

I recently began refurbishing a 1980 Suzuki dirt bike with a plastic gas tank One week after filling the tank with gas containing ethanol the tank developed a 5 inch long split. Is this caused by the ...
0
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0answers
48 views

Can we repair a dead body?

The following passage has been extracted from the book "Organic Chemistry-10th edition by Solomon and Frhyle": "The growth of living things from microbes to elephants rests on organic reactions, ...
0
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1answer
36 views

What is the Chemistry behind “good” and “bad” cholesterol & their relation to Cis/Trans fatty acids?

I have searched Google for this but cannot seem to find an explanation. My question is as follows - what is the Chemistry/Biochemistry behind cis and trans fatty acids resulting in "Bad" LDL and ...
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0answers
17 views

Can I break starch down into glucose units?

I was wondering if starch can be broken up into individual glucose units. Because on a site I saw, it said that through acid hydrolysis starch can be broken up into amylose and amylopectin. However, ...
3
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0answers
22 views

What would make guanidinium ions and urea more effective denaturants of proteins in some cases, but not in others?

Some proteins do not unfold, or only partially unfold due to chaotropic agents such as guanidinium ions and urea. What are some reasons for this?
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0answers
14 views

How to detect azide group on a primer?

I bought azide-labeled primer for click chemistry, but it didn't work. So I want to prove the existence of azide group. How could I achieve this? I found a method to add ...
4
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1answer
41 views

Why does pasta become sticky after being cooked?

This question was posed by my biochemistry professor at the end of a class and then never answered. What I've gathered is that: It has something to do with the denaturing of a protein, since we ...
6
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1answer
35 views

How does dimethyl sulfoxide transport other molecules through skin?

Wikipedia says: Use of DMSO in medicine dates from around 1963, when an Oregon Health & Science University Medical School team, headed by Stanley Jacob, discovered it could penetrate the skin and ...
5
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3answers
58 views

What is tryptose

Occasionally, I work with lauryl tryptose broth for growing coliform. Being a chemical engineer, I suspected at the start that tryptose is a type of carbohydrate because of the -ose syffix. However, ...
0
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1answer
32 views

What makes something biodegradable?

Learning about biodegradable polymers and non-biodegradable polymers. What exactly sets them apart though? Here's the formula from wikipedia for the biodegradable PHB: and here for polypropylene, ...
6
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1answer
324 views

Why do many pharmaceuticals contain fluorine?

What exactly does fluorination of some compound do in a biological sense? I read the following things about what fluorine does for drugs: Fluorine withdraws electron density and can make an acid ...
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0answers
25 views

Drabkin Method for Hemoglobin Determination

Good evening, I have done several measurements of whole blood diluting it in Drabkin's solution. I need to plot calibration curve but I don't know how to. The concentration calculation is done by this ...
5
votes
2answers
77 views

Why is mercury much more toxic when inhaled than injected?

Following wikipedia: Cases of systemic toxicity from accidental swallowing are rare, and attempted suicide via intravenous injection does not appear to result in systemic toxicity,[1] though it is ...
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6answers
7k views

Do all salts taste salty?

Recently, I am learning the production of soluble and insoluble salts. My friend and I have done this experiment at the school lab. However, we want to taste them to see whether they are salty are ...
2
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1answer
92 views

Histidine-Phosphate in Succinyl CoA synthetase and phosphoglycerate mutase enzyme

I would need to know the type of bond of histidine-phosphate in succinyl CoA synthetase enzyme. Can anyone help with this? Is it a Carboxy phosphate anhydride ? Is it the same type of bond of ...
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0answers
28 views

Grapefruit and sugar gelatin like substance

More or less I am trying to figure out how this reaction occurred, so I can reproduce it. On a plate I had an excess amount of sugar with a fair amount of grapefruit juice which was stuck to the ...
2
votes
4answers
131 views

Storage of Urine

Not all may be favorable to this project, but I will explain what I am trying to do. I work at home, and instead of walking a moderate distance to the bathroom and loosing my focus, I've been, at ...
1
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1answer
48 views

Denaturing of Proteins and Nucleic Acids - Effect of Temperature (Heating VS Cooling)

Heating a protein/nucleic acid will disrupt inter-molecular and intra-molecular forces in the tertiary structure. It will also interfere with the shape of the active site if the protein. Does this ...
2
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0answers
37 views

Why would ethanol or water give poor yields in a peptide deprotection hydrogenolysis?

A homework question asks: The following reaction was carried out using ethanol or water as solvents, but gave poor yields in both cases. Suggest why this might be the case and how these problems ...
3
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2answers
61 views

Why is iron used in the body?

I'm writing a report on the spectrophotometric determination of iron. In my introduction I want to briefly explain the importance of iron in the human body. Wikipedia states that "Iron is essential ...
0
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1answer
21 views

How does one analytically quantify whether or not a compound is a SIRT1 activator?

So there has been a lot of noise over whether or not certain molecules activate SIRT1. Resveratrol was thought to be a specific SIRT1 activator, but many have argued against this claim. Similarly, ...
2
votes
2answers
25 views

Optical Density numbers

If it's OD of 600nm I know that's the wavelength used, but what are the other numbers in something like "OD 600nm of 0.6-0.7". The 0.6-0.7?
0
votes
1answer
67 views

Net charge of Peptides at pH1 and pH0

Taking Glycine and aspartic acid. As both the amino acids are fully protonated at pH 0 ad pH 1, how does the peptide bond form? Is it a two step mechanism where the OH from an alpha carboxyl group ...
0
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0answers
19 views

How to calculate the amount of a polymer (PCL) in the chloroform:dimethyl sulfoxide (7:3) to get 9% solution?

I need to calculate the amount of the polymer [mg] in the chloroform/dimethyl sulfoxide with the ratio 7:3 relatively for producing 9% solution. I was using this formula for dissolving the polymer ...
4
votes
1answer
86 views

Why do glucose, galactose and mannose differ in solubility in water?

I don't understand why they would be so different, when the only structural difference is the orientation of hydroxyl groups.
2
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2answers
228 views

Are all anomers diastereomers?

I am told that all anomers are diastereomers. I think this is BS. If there is a carbohydrate with only one chiral center, then changing the configuration of the anomeric carbon gives us enantiomers. ...
4
votes
3answers
865 views

what does the '-1' superscript mean in units?

For example, the rate of a chemical reaction can be expressed in $\mathrm{mol}/\mathrm{L}^{-1}/\mathrm{sec}^{-1}$. Why is it '-1' and not, say, '-2'? Does it change the meaning if the minus is removed ...
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0answers
25 views

How to plot standard curve using D-Galactouronic acid

I wanted to calculate the Pectinase enzyme activity. so how can I plot standard curve using D-galactouronic acid ? also is it possible using glucose ?
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1answer
46 views

In water, will sucrose be hydrolysed by water to form glucose and fructose molecules?

If I dissolve sucrose sugar ($\ce{C_12H_22O_11}$) in water, would the water readily hydrolyse the sucrose sugar to form glucose and fructose sugars?
4
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1answer
39 views

How does aminoguanidine interfere with the formation of advanced glycation endproducts?

This says that aminoguanidine interferes with the formation of advanced glycation endproducts (AGEs) through interacting with 3-deoxyglucosone. But how does it interact with 3-deoxyglucosone that ...
2
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0answers
19 views

Why is cytosine far more vulnerable to hydrolytic deamination than both adenosine and guanosine?

Here's the source for the claim (the half-life is 340 years at 298 K, which is much smaller than that of adenosine and guanosine).