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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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What is the importance of histidine in the buffering action?

What is the importance of histidine in the buffering action in animals?
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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
21 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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1answer
71 views

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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How to rid MRSA on my lower calves that have been getting worse for over a year now [closed]

MRSA in lower right extremity and partial MRSA in lower left extremity/calves/Edema related from lung cancer operation 4 years prior.
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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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What is the result of inhibted oxidative phosphorylation and increased intensity of electron flow in respiratory chain? [closed]

the effect of phyiscal damage of inner mitochondrial membranes is inhibition of oxidative phosphorylation and increase of intensity of electron flow in respiratory chain. explain
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1answer
21 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
37 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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1answer
67 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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Production of ATP Synthase [duplicate]

I have been reading about the ubiquitous use of ATP as an energy source in biology. ATP Synthase is a very complicated protein enzyme. My question is, how could this protein have arisen. To form ...
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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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How to kill fungi and bacteria in heat-sensitive ingredient like bromelain?

How to kill fungi and bacteria in heat-sensitive ingredient like bromelain ?
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How to grow a Spirulina biofilm on a carbon/graphite cylindrical cathode

I am trying to grow a spirulina biofilm on my cathode for a fuel cell but it doesn't seem to be sticking to the cathode. I have a culture of spirulina and I've submerged a few cathodes in it to try ...
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2answers
72 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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Formation of annular structures in carbohydrates

In Lehninger's Principles of Biochemistry, David L. Nelson and Michael M. Cox state that monosoccharides with more than four carbon atoms often have cyclic structures (pyrannoses and furans) and ...
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What use are ketone bodies in low glucose states?

When there is low blood glucose levels, oxaloacetate is converted to pyruvate, and ultimately to glucose. This leads to a state where there is not enough oxaloacetate available and acetyl CoA, ...
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When the present state of knowledge concerning central noradrenergic transmission was established?

Some time ago I began to search for descriptions of the mechanisms responsible for the regulation of noradrenergic transmission in the central nervous system of man and to my great surprise the most ...
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1answer
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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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Is it possible that a pcr product show exact binding as gene but it is vector?

I ran pcr with gene and saw the binding in agarous gel. Then i purified the DNA products and transferred to e. coli. Then after doing miniprep, i ran pcr with positive and negative control. I saw band ...
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1answer
19 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
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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 ...
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1answer
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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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1answer
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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
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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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1answer
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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
25 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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1answer
29 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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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
25 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
290 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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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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1answer
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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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Why does pyruvate from lactate and pyruvate from other sources follow different pathways in gluconeogenesis?

My teacher taught me in a lecture that PEP forms from Pyruvate by two ways, based on their sources, that is - 1. If the Pyruvate was from lactate (by lactate dehydrogenase action), it gets shuttled ...
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How does garlic preparation affect its active compounds or medicinal properties? [closed]

I read the following claims about how to consume garlic: Consume immediately after crushing since the active compounds (allicin) is volatile and gets oxidized as soon as it's crushed Allow to sit 10 ...
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1answer
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Arsenic (V) Reduction to Arsenic (III) by Microorganisms

I am currently doing research on arsenic toxicity in microorganisms, and I learned about arsenic (V)/(III) cycling. Arsenic (III) (usually in the form of arsenite) is generally 50 times more toxic to ...
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1answer
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Struggling to make sense of Km [closed]

So I have two substrates for one enzyme and I measured the product formation-> michaelis menten kinetics. The Vmax for both substrates is the same, the Km however is higher on substrate number 2. ...
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1answer
46 views

Glycolysis step 5: isomerization by triose phosphate isomerase

On the 5th step in glycolysis, triose-phosphate isomerase converts dihydroxy-acetone-phosphate to glyceraldehyde-3-phosphate. Now my question is: Why? Most books and sites I've read only say that ...
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5answers
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Why isn't Fluorine, or Neon, the final electron acceptor in cellular respiration?

I'm a Chemistry student learning about periodic trends. I know that in (many organisms') cellular respiration, oxygen serves as the final electron acceptor due to its high electronegativity. However, ...
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1answer
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Why is free ribose not reduced to deoxyribose rather than the reduction occuring on ribonucleotides

I cannot understand why deoxyribonucleotides are not synthesized directly from deoxyribose, but ribonucleotides have to be synthesized first, and only then can deoxyribonucleotides be synthesized.
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3answers
73 views

Could a mammal convert ingested dissolved CO2 to usable energy?

I'm trying to find out if it's possible that a mammal could orally ingest dissolved CO2 and convert it to energy for body heat, organ function, etc. Unfortunately, most of the scientific sources I've ...
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0answers
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Are potential calories/ATP lost from fat when converted to ketones?

When insulin levels are low, the liver begins to oxidize fat. The liver oxidizes fat by an incomplete process that yields ketone bodies. The incomplete oxidation of fatty acids by the liver yields ...
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0answers
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Does freezer burn affect only the cells on the surface of food?

Suppose i submerge a banana halfway through in a tray with water. Part of the banana is submerged in water, part of it is on the outside. The water and banana in the tray is being put in the freezer ...
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How is Mg2+ in vegetables displaced by 2 H+ ions when vegetables are heated?

I read that Mg2+ ions in vegetables are displaced by 2 H+ ions when vegetables are heated - this explains the color change. But from my understanding, Mg is higher in the activity series than H, so ...
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0answers
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Despite the highly negative free energy change in ATP hydrolysis, why does ATP not spontaneously undergo hydrolysis?

the delta G0 of hydrolysis for two terminal phosphate group is around 7.3Kcal/mol, so why does ATP not breakdown spontaneously? Is it because it has high activation energy?
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about lipid oxidation, does acid fatty transforms in glucose? [duplicate]

Lipid oxidation generates fatty acid and glycerol going into the bloodstream. Can they be converted into glucose by gluconeogenesis or are they turnd into ketone bodies?
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Microalgae with the highest carbon density

I am looking for about species of microalgae with the highest known carbon density. Specifically, I am looking for the highest carbon to volume and carbon to weight ratios when the algae is ...