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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177 views

Where do the protons in the mitochondrial intermembrane space originally come from?

I'm currently reviewing this concept in cellular respiration. The book which I'm using is Reece, Minorsky, Campbell's Biology and while it does a good job at explaining the process involved in the ...
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1k views

Does eating nonsalty food with MSG make you thirsty?

Assume that you're thirsty after eating food that didn't taste salty while you were eating it. Quora posts and https://msgdish.com/msg-problems-and-answers/ still impute the thirst to salt: The ...
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55 views

Depolarisation of post synaptic neuron

When the post synaptic neuron begins to depolarise as positive sodium ions move into it and it reaches threshold- does the inside of the neuron actually switch to being more positive than the outside? ...
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Valence electrons in DNA nucleotide addition [closed]

Can anyone explain the movement of valence electrons during the nucleophilic attack that occurs during DNA synthesis? The 3' oxygen starts with two lone pairs of electrons but what happens during the ...
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123 views

Does our brain use up more ATP after smoking cannabis?

kind of an amateur here. If the firing of the neurons' signals uses up some ATP, and smoking cannabis makes them fire off more quickly, do our brains use up more ATP to sustain that rapid firing?
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Is the chemical composition of urine detrimental or beneficial for a tree?

Seeing as a lot of people around the world urinate against trees it came to mind that I never thought about how the tree responds to this. Is it detrimental for a tree if people urinate against them? ...
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Where does the proton come in the reduction of NAD?

In our curriculum biology textbook the reduction of NAD+ is depicted as follows: NAD+ + 2 H+ → NADH + H+ If this proton in the products was not present in the reactants, then where does it come ...
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Where do the lysines come from during ubiquitination?

I know that Ub forms an isopeptide bond with lysine, but where do the lysine come from? Are they just always available for the Ub to find to during the ubiquitination process? Is there a free lysine ...
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Cadmium Poisoning and Toxicity Mechanisms

Is anyone aware of the toxic mechanisms of specific instances in which cadmium ions can interfere with cellular functions resulting in acute cadmium poisoning?
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Toxic Metals and Oxidative Phosphorylation

I was reviewing the toxicity of certain toxic metals, specifically cadmium and their effect on Oxidative Phosphorylation and Cellular Respiration, I have found that metals such as cadmium inhibit ...
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What is the fastest way to crystallise lysozyme (for student course)?

High school sudents are going to visit my university and I plan to demonstrate crystallisation of lysozyme. I ordered pure lysozyme from VWR. I can easily crystallise this within 15 min in batch (4% w/...
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826 views

Difference between prions and amyloid proteins?

Amyloid and prions are misfolded proteins, but what, if any, is the difference between them? Is amyloid a type of prion with a fibrillar structure?
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Is oxygen's paramagnetism biologically relevant?

It seems our most common everyday O2 molecule happens to be a paramagnetic one (see https://en.wikipedia.org/wiki/Oxygen). But, does this have a biological relevance as well? In other words, Do any ...
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389 views

Do chaperone proteins misfold?

If molecular chaperone proteins assist in the folding process of other proteins and misfolded proteins, can chaperone themselves misfold since they are also proteins? What would happen if chaperones ...
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How can sodium and potassium from burned organic matter (ashes) reenter the ecosystem?

If you thoroughly burn something you end up with bunch of oxides and hydroxides, as far as I know. Sodium and potassium hydroxides are plentiful in ashes, which is why lye was created by soaking ...
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23 views

Can someone help me interpret these charts on fluorescent polarization?

I have to present an article about binding designed proteins to fentanyl for my biochem class; I understand everything except how to interpret these charts on fluorescence at the very top of Figure 2a:...
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1answer
2k views

What is the importance of alkaline condition in biuret test?

Biuret test aims to quantify the amount of protein in a given unknown sample. Biuret agent contains copper sulphate, sodium potassium tartrate and Sodium hydroxide. Coppper ions form the complex of ...
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49 views

How can P450 distinguish between foreign and native compounds?

It is my understanding that P450 enzymes are capable of selectively degrading compounds that enter the cell from the outside (e.g. synthetic drugs) without damaging compounds that are metabolic ...
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29 views

Biological Nitrogen Fixation

I just studied Biological Nitrogen Fixation and saw it's reaction but i do not understand why there is 8 electrons and 8 protons are involved and Hydrogen molecule is formed side by side along with ...
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1answer
266 views

Where would vegetarians/vegans get a substitute of hemo/myoglobin from?

As far as I understand, there is a difference in the iron absorbed from meat than from other sources like grains and vegetables. If this is the case, is it possible that not ingesting the hemoglobin ...
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1answer
81 views

Why does carbon dioxide diffuse easier through the bilipid layer than oxygen?

When gas exchange occurs during respiration, the pressure of oxygen in alveoli is around 105 mmHg, whereas in the blood vessels in close contact with alveoli is 40 mmHg. For carbon dioxide the values ...
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149 views

What happens to drug metabolism when CYP450 enzymes are presented with two substrates

What happens when two substances, both substrates for Cytochrome P450 metabolism, are both present in the bloodstream? For example, with sertraline and cannabidiol (CBD), if someone took a sertraline ...
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1answer
145 views

How are fingerprints formed?

I know what influences the fingerprints to be unique always. But what actually process is taken to make these as we grow?
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650 views

PBS or TBS, where cannot use each buffers?

As you know, Tris buffered saline and Phosphate buffered saline is multipurpose. For finding each buffer's use, there's so many use experiment for PBS and TBS. TBS uses for western blotting, and PBS ...
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Why might a cell have no respiratory reserve capacity?

I am trying to understand why a cell might have minimal respiratory reserve capacity in the presence of unlimited substrate supply. This essentially means that the oxygen consumption rate (OCR) of the ...
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1answer
604 views

Why is there a layer of moist lining the inner walls of alveoli?

I'm taught that the walls of the alveoli are moist, so gaseous oxygen molecules can dissolve into this water. This then allows the dissolved oxygen (liquid state) to diffuse faster from the alveoli ...
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Difference in Basic Amino Structures

I'm having a hard time understanding why my slides in my biology course have two different representations of the "basic structure" of the amino acid: 1: 2: The top one seem like what I would ...
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What is the composition of a standard diluent buffer in a leptin ELISA kit?

I am trying to find the composition of the diluent buffer used for the dilution of a human leptin stock to be used in an ELISA assay. The manufacturer of the kit (https://www.thermofisher.com/elisa/...
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How is Saccharomyces cerevisiae grown on acetate and ammonium able to produce TCA intermediates?

I am working with a metabolic model of Saccharomyces cerevisiae and I am studying its growth on acetate and ammonia. I am performing Flux Balance Analysis to compute the growth rate and then I am ...
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Can an epileptic seizure start in the spinal cord?

My understanding of an epileptic seizure is caused by "invalid electrical signaling" in the brain. Can these start from the spinal cord (outside the brain) and move into the brain and cause an ...
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1answer
36 views

Where does the additional 1 proton cost of oxidative phosphorylation come from?

I've been quite confused by the source of the additional 1H+ cost right now. I know it costs the F1Fo-ATP synthase 3H+ to produce an ATP, and it is also stated that: ADP3−cytoplasm + ATP4−matrix → ...
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1answer
50 views

Sweating at all temperatures

Is sweating possible if surrounding temperature is below the body temperature? How the sweating occur due to the combustion of food?
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256 views

What are the sources of molecular hydrogen in human breath?

In the BBC News article CES 2019: Tech preview of the expo's hottest new gadgets there is a new product that one can use to measure the hydrogen in ones breath, and this is supposed to have some ...
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Why are higher doses of atropine required to produce central effects?

Reason given in my book is restricted entry into the brain..is it something to do with the chemisty?
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100 views

Why biologic systems tends to become more complex?

From elements, chemical compounds, cells, multicellular organisms, society evolves and with each step possibilities increase and things get complex. We are builing structures like ribosome builds ...
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138 views

Osmotic Pressure Clarification

My textbook states that the higher concentration of solutes, the greater the osmotic pressure will be and the greater the pull of water in will be. However, osmotic pressure is defined "as the ...
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1answer
55 views

can magnesium bicarbonate be absorbed in the mouth?

Can Magnesium Bicarbonate be absorbed in the mouth?" Magnesium Bicarbonate occurs naturally in some mineral waters.
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1answer
167 views

Inhibition of beta-oxidation by acetyl- or malonyl-CoA

Which molecule, in excess, inhibits beta-oxidation? a. Acetyl-CoA b. Malonyl-CoA The answer to this question seems debatable to me, as I think both are correct. However, according to my professor, ...
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1answer
19 views

Technical reason that specialized embryonic cells form

During the embryonic stage of human development, rapid cell division occurs and specialized cells form to build the various parts of the developing fetus. I'm curious: Why technically do specialized ...
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50 views

Is studying chemical and physical properties of chemical substances that make up organisms really a task of molecular biology?

I have read in a high school textbook that (translated into English by myself): "Branch of science that concerns itself with studying chemical and physical properties of substances that make up ...
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1answer
61 views

Why don't primates have galactose-alpha-1,3-galactose (alpha-gal), but other mammals do?

I read in wikipedia that: Galactose-alpha-1,3-galactose, commonly known as alpha gal, is a carbohydrate found in most mammalian cell membranes. It is not found in primates, including humans. My ...
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65 views

Are the chemical constituents of human bodily fluids similar to sea water?

I have heard a comparison of human bodily fluids to sea water from various sources in the past. The most notable was a teacher who claimed, if I remember correctly, embryonic fluid is comparable in ...
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1answer
53 views

Resting membrane potential in cells

My textbook says “Among K+, Na+ and Cl-, K+ contributes to the resting membrane potential the most, because it has the greatest permeability across the membrane.” I agree with this, but I’m just ...
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329 views

What is the difference between a signal peptide and a transit peptide?

From what I know, the two names are used interchangeably and I haven't found any resource which says otherwise either. Is there at all any difference, is there a transit peptide that is not a signal ...
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38 views

Can we spike with a different enzyme to a SYBR Green Master Mix?

I followed the standard SYBR Green Protocol for doing a qPCR. For which I used 10 uL of 1X SYBR Green Master Mix Forward Primer and Reverse Primer (each at a final conc. = 8.5 uM) Template (unknown ...
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1answer
94 views

Design rules for DNA linkers

I want to use double stranded DNA linkers to physically bind two "things" together, by grafting ssDNA on each one of them and using DNA hybridization as the locking mechanism. I do not expect the ...
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2answers
319 views

How does zoo and laboratory animal feeding work?

What steps are taken to ensure those animals are fed adequately? When dealing with larger populations of animals, how is it ensured that all of those animals received food during a certain time period,...
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How do the chemicals in our skin react with stainless steel?

What acid/chemical in human skin can react with stainless steel to leave a black mark on the skin? Why is it secreted/produced in larger quantities by some people and not by others?
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788 views

Why don't the heads of phospholipid bilayers repel hydrophobic molecules?

What I Think I Know: Hydrophilic and hydrophobic things repel each other. Since the cell membrane contains hydrophobic tails, it is difficult for hydrophilic molecules to pass through the cell ...
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177 views

What characteristic(s) of inverse agonists allow for inhibitory effects?

I know that inverse agonists have similar structure to its complement agonist; and, as a result, they have the ability to bind to the same receptor, causing an inhibition of the pathway considered. ...

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