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

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Effect of a double mutation on the stability of a folded protein?

the question is shown as follows: My reasoning is that the mutation leads to stabilisation of the protein as Tyr121 is a better H-donor than Ser53 therefore stronger H-bonds formed. Also there seems ...
2
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1answer
27 views

Deriving kinetic equations for a complex reaction system

I have a system of protein reactions that I've derived differential equations for the kinetics of. I'm using them to run simulations to fit the rate parameters, but the simulations at present are ...
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0answers
10 views

Determine the amount of DMSO? [on hold]

Determine the amount of DMSO needed to make 20 mM and 10 mM of Compound X in (uL). (MW: 584.32; 1.92 mg)
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0answers
27 views

What is the structural difference between ketogenic amino acids and glucogenic amino acids?

We know some amino acids could go in ketogenosis path way ,some in glucogenic and some in both ..i 'm wondering to know what the differences are between the amino acids the make this situation.
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13 views

Hydrolysis of esters, amides [closed]

At what pH the ester or amide groups present in the drugs get hydrolysed, in the human body? Does it depend on the particular cell physiology?
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1answer
16 views

Enzyme Specificity vs Selectivity

Background: I can see a difference in stereoselective and stereospecific reactions in organic chemistry. However, both terms are used interchangeably as synonyms in a biochemistry class. Question: ...
12
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1answer
905 views

Why/how is blood red? (colours of hemoglobin)

Oxyhaemoglobin is red, deoxyhaemoglobin is bluish-purple, and carboxyhaemoglobin is a cherry red colour. Evidently in the porphyrin around the iron molecule in heme there is a conjugated pi system ...
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1answer
13 views

Does mechanotransduction of cells play a role in the biocompatibility of titanium?

What exactly is mechanotransduction? The definition seems to vary from source to source. Some indicate that mechanotransduction is the underlying principle where cells pull on the surface they grow on ...
2
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0answers
20 views

Microarray SPR imaging vs “regular” SPR?

Background: I am taking a biochemistry course, and we have had some basic introduction to surface plasmon resonance (SPR). I don't have a very strong background in biophysical chemistry. Task: I am ...
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0answers
9 views

Thiosulfate from N-acetylcysteine

Can you derive thiisulfate (S2O3 (-2)) from n-acetylcysteine (C5H9NO3S) in a biological system such as the airways? If so, how?
3
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1answer
40 views

l- versus d-glucose

I recently purchased Dextrose from a local bulkfood store. I want to use it instead of table sugar. My concern is that it may be l-glucose instead of d-glucose. According to Wikipedia l-glucose is too ...
3
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3answers
81 views

Why is the Mg2+ ion preferred over other ions in chlorophyll?

Chlorophyll has a $\ce{Mg^2+}$ ion. Why is it preferred over other ions? I mean, what happens if there is $\ce{Zn^2+}$ or $\ce{Ca^2+}$ or any other cation instead of $\ce{Mg^2+}$?
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12 views

Differences between anionic and cationic surfactant in DNA extraction?

What's the main difference in DNA extraction between using an anionic surfactant (like SDS) or a cationic surfactant (like CTAB)?
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0answers
9 views

Can (2,4-dinitrophenyl)hydrazine be used in osazone test?

For osazone test we use phenylhydrazine but what difference it would make if we replace it by its derivative (2,4-dinitrophenyl)hydrazine and will there be any change in crystal structure of the ...
13
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2answers
187 views

Why does fluorine act as a leaving group in organophosphates?

C-F bond is the strongest single bond in organic chemistry with a bond energy of $\ce{453 kJ\,mol^{-1}}$. And it is very difficult to break this bond and F does not act as a leaving group. However, ...
3
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0answers
15 views

Measuring reaction rates when reactants and products both have (different) molar extinctions at the chosen wavelenghth

In my Biochem labs we would always measure the consumption of NADH, and they always noted that it was useful that NAD+ had essentially no absorbance at 340 nm, which allowed us to directly relate ...
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1answer
23 views

Why is the effect of competitive antagonist less than the effect of non-competetive antagonists?

Drugs can be provided as a competive or non-competitive form of agonists. But the effect of non-competitive antagonists is much more than the other, so what is the cause of that? And are there some ...
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0answers
23 views

Molecular mechanism describing the action of serotonin [closed]

I am doing an assignment of serotonin and i was wondering if you could explain how serotonin's molecular structure gives it its favorable properties. I have done so much research on the molecular but ...
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0answers
21 views

Molecular mechanism behind the action of neurotransmitter Citalopram [closed]

What parts of the neurotransmitter Citalopram (which blocks the reuptake channels of Serotonin) on a molecular level enable it to do its job. the chemistry behind it for a grade 12 chemistry ...
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0answers
13 views

Proteolytic enzyme assay using casein as the substrate

To determine the proteolitic activity of an enzyme, the enzyme assay can be used using the casein as the substrate. In the laboratory can I use a fresh milk sample instead of casein?
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1answer
26 views

What is the chemistry behind heat produced when blood is bleached?

When I discard blood (20-40 mL) in a beaker containing bleach (400mL), I can feel that heat is produced in the beaker. What is the chemistry behind it? Will heat be produced due to Lysis of haem ...
2
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1answer
58 views

Why can't electrons be transferred using hydrogen ions?

I have a homework question that asks: Recognizing how oxidation and reduction occurs is essential for analyzing and understanding biochemical reactions. Which of the following methods would NOT ...
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0answers
22 views

How to calculate molar concentration of phenol red when mixed with water and a buffer?

The concentration of phenol red is 1E-4 M. The initial volume used was .1 mL and is then mixed with .9 mL of water and 4.0 mL of a .1M borate buffer of pH 9.8. I used a simple M1V1 = M2V2. Where M1 = ...
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0answers
19 views

Lookup for transporter locations in human organisms [closed]

I am scared that this question is a bit naive and probably even wrongly placed here... However, I'll give it a try and hope for the best :) I am interested in several transporters and cotransporters ...
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1answer
21 views

Difference between biosynthesis in organism versus lab

Are there different terms for biosynthesis of a compound naturally in an organism versus the biosynthesis using chemicals in the laboratory or is it just "biosynthesis"?
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1answer
117 views

Relation between Gibbs energy and net reaction rate

I have come across some papers in biochemistry that seem to claim that a reaction can be "near equilibrium" even though the flux through the reaction (net reaction rate) is large. For example, this ...
3
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1answer
155 views

Find the number of water molecules “embedded” in sucrose

Recently I got a question as follows: How many molecules of water are joined with 12 atoms of carbon in a molecule of sucrose ? (A) 12 (B) 11 (C) 6 (D) 10 I am unable to ...
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1answer
23 views

What is a prosthetic group of protein? What are prosthetic groups?

I have found this term while I studying the topic of ETS in respiration in plants.
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0answers
42 views

Comparing pKa of Alpha and Beta Amino Acids

The $\mathrm{p}K_{\mathrm{a}}$ of the functional groups in L-glutamic acid (shown above on the right) from left to right are $4.1, 9.5$ and $2.1$. Predict the $\mathrm{p}K_{\mathrm{a}}$ values of ...
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1answer
39 views

Is it practical to extract zymase from yeast for ethanol production?

Suppose I wanted to make some ethanol fuel. Normally, I would get yeast, mix with water, add sugar and wait. However, there is an enzyme (zymase) in yeast that does this. Looking at the Wikipedia ...
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0answers
26 views

What are some technologies/biosensors for real time kinetic analysis of reactions? [closed]

I am in a lab that has used surface plasmon resonance (SPR) and ELISA very heavily over the past few years, and we are thinking of getting a new machine. I'm wondering what other technologies exist ...
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0answers
27 views

How is adenosine synthesized in biology?

I understand the constituent parts of adenosine, ribose and adenine. I also know adenosine can be broken down from ATP anabolically. However, I am interested to know whether there is also a catabolic ...
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0answers
25 views

Biosynthesis of Xanthoxylin

Anyone can find a source for or explain the biosynthetic pathway for Xanthoxylin? It's the last practice problem I have for an exam, and I just can't seem to find info on it. Thanks!
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0answers
23 views

Mechanism: explanation of final step in synthesis of the thyroid hormones (T4, T3)

In the following mechanism for the synthesis of T3 (triiodothyronine) on thyroglobulin, what are the factors causing the last step to occur? Does it have something to do with the electron density of ...
3
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1answer
63 views

What is the empirical formula of Haemoglobin?

Everywhere I look on the internet tells me a different formula. Are there genuinely different formulas for Haemoglobin, or are some of my internet sources incorrect? (I know there are different ...
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1answer
34 views

Which coloring agents are responsible for the color in red tea and yellow tea?

Have this question in a biochemistry course, can't seem to find it anywhere. Anyone happen to know an alkaloid or something else involved? Thanks a lot!
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1answer
55 views

Why is vitamin C called an antioxidant?

According to Wikipedia, vitamin C (ascorbic acid) "may also act as an antioxidant against oxidative stress," and is "widely used as a food additive, to prevent oxidation." But acids are, by ...
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0answers
23 views

Water and Bonds [closed]

I am doing a study packet and it asks Water contains what bonds. I said covalent bonds. Then it says The electron bully is___. It is therefore ___charged. The other element,____, is the electron loser ...
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1answer
49 views

Question about DNP derivatives of amino acids (specifically epsilon-DNP-lysine)

I have a pretty basic biochemistry question but am having trouble finding the answer to it: Normally, DNFB (dinitrofluorobenzene, or 1-fluoro-2,4-dinitrobenzene to be exact) reacts with just the ...
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0answers
31 views

How do I analyse this data? (optimization experiment)

I conducted an experiment to find the optimal concentration for sugar in yeast respiration, and this is the data I found: What do I do from here? Do I just fit a linear model on the increasing ...
5
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1answer
45 views

Comparing Methods of Determination of Dissolved Oxygen Content in Water Sample

I am currently doing an IB Chemistry Individual Investigation on dissolved oxygen in water samples by using Winkler method. However, my teacher suggested that I have to use oxygen probe as a standard ...
2
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1answer
41 views

Is 98%+ purity Reagent Grade Ca-EDTA powder as safe to use as USP Grade in the body? [closed]

Is $98\%+$ purity reagent grade $\ce{Ca}$-EDTA powder as safe to use as USP grade in the body? Or, does the reagent grade have unsafe impurities that USP grade would not have even though they are the ...
0
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0answers
39 views

dihedral angles [duplicate]

My guide asked me to measure the dihedral angles of a poly-peptide chain.There are 4 atoms in between two planer surface(2 atoms in each plane).(refer dihedral angles wikipedia) There is a formula for ...
0
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0answers
22 views

dihedral angles [duplicate]

My guide asked me to measure the dihedral angles of a poly-peptide chain.There are 4 atoms in between two planer surface(2 atoms in each plane).(refer dihedral angles wikipedia) There is a formula for ...
1
vote
1answer
41 views

Is exposure to amyloid beta proteins dangerous?

Recently, I began working in a lab in which our main area of study is Aβ peptides. My concern is whether or not exposure to high levels of Aβ proteins is hazardous. I suspect that the peptides cannot ...
1
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1answer
80 views

Hydrophilic vs water soluble?

Is the term 'hydrophilic' a synonym of 'water soluble' or can you have a molecule that is water insoluble but hydrophilic (or water soluble and not hydrophilic)?
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0answers
30 views

Formose reaction in dry methanol catalysed by calcium methoxide

I've heard about the formose reaction which produces carbohydrates from formaldehyde. I wonder if edible carbohydrates, such as glucose or fructose, could be efficiently produced by dissolving ...
1
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0answers
26 views

Glucose to Glucose-6-phosphate [closed]

What does actually occur- ATP is hydrolysed and esterification between glucose and HPO4^2- (formed as a result of hydrolysis) take place to form Glucose-6-phosphate or nucleophilic attack of O- of ...
2
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1answer
49 views

net charge nucleobases at alkaline conditions

While doing anion exchange chromatography of short oligonucleotide, I have noticed that at $\rm pH=12$, the oligo- retains longer on the column than the same oligo- at $\rm pH=8$. I thought the reason ...
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0answers
13 views

how much of each solution do you need to prepare 500mL of a reagent that contains ..? [closed]

Given stock solution of glucose (1000mM), asparagine (100mM) and NaH2PO4 (50mM), how much of each solution do you need to prepare 500mL of a reagent that contains 50mM glucose, 10mM of asparagine and ...