Questions tagged [biochemistry]

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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89 views

Can mold grow on copper pipes?

Couple months ago noticed something was literally, for lack of a better term, eating paint off of lead pipes. And I noticed joints in copper pipe seemed to be "leaking" flux. Now all the water in my ...
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Why are proteins considered Informational macromolecules?

I can understand somewhat why DNA and RNA are considered Informational macromolecules, because they contain genetic information. But why are proteins considered Informational macromolecules?
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Can catecholamines degrade back into tyrosine, or, is synthesis irreversible? (in human body)

Catecholamines like dopamine, noradrenaline and adrenaline are broken down with enzymes that catalyze the reaction. Can they degrade back into tyrosine (a conditionally essential amino acid), or is ...
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Any phyla in Animalia that does ammonia assimilation?

A key step in nitrogen metabolism is the initial assimilation of inorganic ammonia into amino acids. Are there phyla within Animalia that do assimilation of ammonium (NH4+)? Phyla with symbionts from ...
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What causes the overactivity of keratin production and expression in the cells of the nail bed/ nail matrix after some traumata?

What is the cellular mechanism of traumatic(sterile) onychodystrophy(hypertrophy)? I.e one hits his toenail and has it removed twice( once after the first trauma and then again 3 years after the first ...
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how can we identify the novel protein amino acid sequence and function? [closed]

if there is a novel protein, how would you know the amino acid sequence and how would you determine the number of subunits and the function of that protein? Specifically what molecular techniques we ...
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1answer
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Values of the blood tests pancreatic amylase and lipase

Anyone know what is considered slightly elevated, moderately elevated and strongly elevated values of pancreatic amylase and lipase? Many different laboratories in my country divide between these ...
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Toxicity of stannous fluoride in toothpaste?

I recently purchased a new brand of toothpaste, and when I looked at the medicinal ingredients, it listed stannous fluoride 0.454% w/w, instead of the regular sodium fluoride. I was a bit concerned ...
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How to recalibrate qpCR reading when incorrect qty of solution is added during DNA elution step?

I have 20 viral DNA samples collected for 6 time points. The DNA content varies over time My DNA extraction protocol step suggests that in the last step of the protocol during elution I had 100uL of ...
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Examples of alkali metal and halogens covalently bonded in biological molecules?

Divalent and monovalent ions are often non-covalently bonded in biological molecules, they are primary building blocks of the machinery of biology. Iodine, the halogon in period 5, is covalently ...
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Does the zeta potential of a nanoparticle generally take into account ligand charge?

For example, if I had a quantum dot nanoparticle with conjugated linker peptides capped with polyarginine tracts. Would the localization of negative charge from arginine change the zeta potential ...
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1answer
48 views

Why doesn't copper affect human skin?

It's been known for a long time that copper has antimicrobial properties, but if it is so potent, why does it seem to have no effect on human skin or really any large animal?
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Why does Porous-tube Nutrient Delivery System cultivation improve nutritional quality of Okinawa spinach (Gyruna bicolor)?

I wrote a review paper and it involves in growth system of a plant “Okinawa Spinach (Gynura bicolor)”. A research of (Wang, Fu, & Liu, 2015) reported that Porous-tube Nutrient Delivery System (...
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Ratio of bleach to water required to disinfect COVID-19?

I am confused about the needed ratio of bleach to water required to disinfect COVID-19 from surfaces. The guide on CDC states that: https://www.cdc.gov/coronavirus/2019-ncov/community/home/cleaning-...
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1answer
43 views

Relationship between bacteria size and temperature?

I'm, doing a research in a TOC (total organic carbon) degradation in a BAC (biologically active carbon) filter for the grey-water treatment. Recently, I started to wonder if there is a relation ...
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Why is Ibuprofen contraindicated in asthma patients?

So yesterday a patient showed up at the clinic with a massive swelling in his left face region. Upon examination it was found to be due to infected first premolar. Dentist recommended him to get the ...
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Does the composition of a meal play a big, or small, role in food's thermogenic effect on the body?

Reading in: "Diet and Health: Implications for Reducing Chronic Disease Risk / Calories: Total Macronutrient Intake, Energy Expenditure, and Net Energy Stores" [NCBI Resources]: "The thermogenic ...
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75 views

How are logarithmic trendline equations used to determine antibody concentrations in ELISA?

For example, say you have plotted a standard curve and managed to obtain a logarithimic trendline equation like: y = mln(x) - b And you are working with data that includes: a) standards,their ...
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Is it possible to artificially induce a 40°C fever in a controlled and safe manner? [closed]

In search for any possible new treatments for COVID-19, I am of the understanding that the SARS-nCoV-2 virus may suffer deterioration at high temperatures and high humidity, to perhaps weaken it ...
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50 views

Circulating Tumor Cell vs Circulating Tumor DNA

I'm a little confused about the wording of these two phrases and under which context the epithelial-mesenchymal transition occurs. For example: Is it the circulating tumor cell that releases the ...
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How to analyze phosphorylation shift by western blot?

I want to see the phosphorylation shift in my protein of interest. I have created a point mutation in my protein. so that it will not able to go for the phosphorylation compare to my control. i want ...
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1answer
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How exactly can a drug affecting squalene epoxidase affect the methylation cycle, necessitating the use of 5-MTHF?

I found a case report in which the authors say that Terbinafine might have possibly affected the methylation cycle in a patient, necessitating the prescription of 5-methylfolate to correct the ...
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Rescuing a virus from naked (c)DNA

Reading the articles it seems that for several human virus strains, synthesizing the full-length genome then electroporating into vero cells and incubating a few days gave birth to living viruses that ...
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Tryptophan side-chain structure, how should it be orientated?

I would like some clarification on whether it matters where the NH and double bond are placed in these two structures of tryptophan (W) that I drew. I marked the right side as correct and the left ...
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What happens when you cook tree spinach with aluminum?

The Internet is filled with warnings that you shouldn't cook tree spinach(Cnidoscolus aconitifolius) in aluminum, because it will react and create toxins that cause explosive diarrhea when consumed. ...
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How can one relate in vitro studies of caffeine (dose expressed as concentration) to dietary intake of caffeine (dose in mass)?

Having difficulty making the data in the below charts to apply to daily life. What is the right interpretation and implementation? How are the “in vitro” results of the below charts relevant to levels ...
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1answer
48 views

Bimodal frequency distribution of size of protein loops

The graph of number of amino acid (AA) residues in a loop Vs the frequency of their occurrence in proteins largely follows a tending-to-zero pattern. However, there appear to be some specific number ...
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1answer
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In vivo, does it take energy to move double bonds from cis to trans in long chain unsaturated fatty acids

In vivo, I understood that because all polyunsaturated fatty acids bonds are -cis they are crowded, kinking the molecule, and because of that, the oxidative enzymes cannot initially access them. They ...
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About the mechanism of coupled reaction/metabolism with ATP

I am not in the field of biochemistry so this may be a rookie question or misconception. I heard occasionally about the energy "released" from ATP hydrolysis fueling (endergonic) biological reactions....
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What makes iodine an effective antiseptic?

I'm thinking about tincture of iodine, potassium iodide (Lugol's), and povidone-iodine (PVP-I) specifically, which, as is my understanding, work by solubilizing elemental iodine in an aqueous solution....
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What's unique for vitamin B-12 group?

I've been trying to figure out what makes the vitamin B group really big with 8 vitamins. Chemically they have different structures. Solubility: not only vitamins from this group are water soluble ...
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1answer
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How to derive Hill equation (one specific part)

There is just one specific step in the derivation of the Hill equation for haemoglobin which I can't understand. Step from: $Y = \frac{(p\ce{O2})^n}{K_d + (p\ce{O2})^n}$ To: $Y = \frac{(p\ce{O2})^n}{(...
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Can microbes become “overweight”?

Just out of some weird thoughts, can a microbe (any single-celled organisms, accepting answers for both prokaryotes and eukaryotes) ingest too much food (e.g. via absorbing too much involuntarily ...
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Can bacteria pick up lethal plasmids?

I am sorry if this question is too general, and does not have any concrete answer. I was explaining to my non-biology-background friend about plasmids and how they are picked up by bacteria from the ...
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Which type of test tube should not be used for blood collection?

The following question is presented in my biology textbook: You are required to draw blood from patient and keep it in a test tube for analysis of blood corpuscles and plasma. You are provided with ...
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A question about L-Citrulline

I know that L-Citrulline enters in the second step of urea cycle in the liver mitochondria and I wonder if a person takes an overdose of L-Citrulline wouldn't that cause mild hyperammonemia or at ...
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85 views

What are the disadvantages of myelin

The myelination of axons has plenty of advantages. It increases signal speed in axons, and thereby reduces reaction times. This is, of course, very good for the survival of the animal in question. ...
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How much heme is in cooked pork and beef; why is cooked pork (“the other white meat”) not red?

The new video See how Impossible Pork will make you forget about pig meat includes a very short discussion of the addition of heme to the product to make it taste like beef the deep red color of a ...
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1answer
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Why does absorption (at 260nm) of ssDNA increase with temperature?

In the graph below, I understand why A260 of double stranded DNA would increase with temperature increase, as more of the DNA becomes single stranded (and A260 of ssDNA is higher than that of dsDNA ...
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117 views

Regulation of the TCA cycle and glycolysis by adenine nucleotides

Why is the tricarboxylic acid cycle regulated by the ADP/ATP ratio as stated in the following quote : Isocitrate dehydrogenase is allosterically stimulated by ADP, which enhances the enzyme's ...
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Appropriate regeneration of StrepTrap HP columns for FPLC

My question is related to protein purification using a ÄKTA FPLC. We used StrepTrap HP Columns (1 ml column Volume (CV)) from GE Healthcare Life Sciences to purify a strep-tagged protein. In the first ...
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A question about cancer antigens and their mechanism [closed]

Can you name the most common antigen that cancer cells in general can't live without?
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Where do methyl groups in the human body come from?

Where do methyl groups in the human body or other mammals come from? Do we synthesize them (where?) Do we get them from our diets (in what? anything beside methionine?) Do our gut microbes produce ...
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1answer
87 views

what is the princlple of using DMS (Dimethylsulphate) for structural analysis of rRNA?

I want to check the secondary structure of rRNA (PTC) in a particular position by using DMS footprinting. I have deleted the modified nucleotide (m5c) which is present in the PTC and it helps in the ...
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1answer
60 views

Glucose 6-phosphate dehydrogenase: reaction mechanism

I have searched the internet for the reaction mechanism of G6PD but couldn't find it, so I am asking whether anyone here knows its mechanism and whether they could recommend some sources that give ...
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1answer
128 views

How does SDS-PAGE separate based on mass?

In SDS-PAGE, electric field and mass-to-charge ratio are approximated to be constant for all proteins. Also, if $F=qE =ma$, then $\frac{m}{q}a=E$. Thus, all proteins must migrate with a constant ...
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How does lipoid pneumonia lead to acute respiratory distress syndrome (ARDS)?

How does lipoid pneumonia lead to acute respiratory distress syndrome (ARDS)? The vaping illnesses that have been happening on the news in the United States are being caused by the federal ...
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Do pyrocalciferol and isopyrocalciferol form in vertebrate skin?

I heard that pyrocalciferol and isopyrocalciferol can only be formed above 100°C/212°F, yet some images in the web depict them as forming in vertebrate skin. So, I wonder if pyrocalciferol and ...
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How many molecules of ATP are actually produced in aerobic respiration?

I have been through the process of aerobic respiration a few times in different text books and almost every book quotes a different value for the number of ATP molecules produced. The consensus seems ...
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Assembly of polypeptides expressed from different chromosomes to make a fully functional protein

In case of human beings, the whole genome is divided in 23 pairs of chromosomes in somatic cells. It has been observed that in case of many proteins (e.g. immunoglobulins, hemoglobin) different ...

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