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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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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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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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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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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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Why do plants store energy as carbohydrates and not as fats?

In my introductory biology class, we are learning about biomolecules. The textbook says fats are a more efficient energy store than carbohydrates. So my question is - why would plants store their ...
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How much energy we get from oxygen?

During a whole day breathing, how many kcal or watts do we get from the oxygen we breathe?
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Why is the heart not in the middle of the body?

All mammals that I can think of have a high degree of bilateral symmetry (In fact, almost every animal I can think of is like this). So why is the human heart not exactly in the middle of the body? ...
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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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Does osmosis require a protein channel?

Earlier today, I undertook an exam which featured a question regarding the stickiness of mucus in a person diagnosed with CF's. We had to explain why they had stickier mucus than a 'normal' person, ...
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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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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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Human Digestion of Cellulose?

Most animals can digest the cellulose in grass because of the anaerobic bacteria called Fibrobacter succinogenes living in their rumen (gut). The bacteria produces the enzyme cellulase and is ...
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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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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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Cells created using differently aligned proteins

I remember reading that scientist were making cells (I assume bacteria), that used differently oriented proteins to create a whole new class of life. Because apparently right and left aligned proteins ...
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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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How does water buffer a sudden drop in temperature?

A property of water is that it is slow to heat and cool. According to my biology book, some energy from an increase in temperature would spent breaking hydrogen bonds, so that temperature does not ...
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3answers
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Do we consume dna, proteins of other organisms?

When we eat raw meat, e.g. chicken or fish, we are actually consuming the DNA, proteins etc. which are present in their cells. Wouldn't this affect our cell functions as this DNA might enter our ...
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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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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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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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How will changing the concentration of a Tris buffer affect amylase enzyme activity?

For instance if you increase the amount of Tris but pH still does not change then will the enzyme activity still proceed normally? If it does change the pH will it change enzyme structure and why?
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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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Does a generator potential pass along a nerve the same way an action potential does?

I have read that a generator potential is a localized depolarization of a membrane. Does that mean that it does not pass along a neuron the same way an action potential does ? If not, then how do ...
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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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2answers
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How many cyclic and non-cyclic photo-phosphorylation is required to produce one molecule of glucose?

In non-cyclic photophosphorylation 1 ATP and 2 $NADPH_2$ molecules are produced. In cyclic photophosphorylation 2 ATP molecules are produced. For production of one molecule of Glucose 18 ATP and 12 $...
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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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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 there a reliable source for storage and stability of reducing agents like DTT?

Reading the literature on DTT, one is confronted with a confusing mass of papers; some claim that a 1M solution in water is stable, other papers say it is not. I use the reaction with DTNB to show ...
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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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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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What is the difference between the mitotic spindle and microtubules?

In mitosis, I understand that the centromeres line up on the spindle. I also know that the centrioles form microtubles between the centromeres during mitosis in the metaphase. But, are microtubles ...
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Why would lactate be high in diabetics?

Why are lactate level high in diabetes? For example, type II diabetes are resistant to insulin. If those patients are insulin resistant their gluconeogenesis should be working at a high rate and, ...
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Cell biology - Resting membrane potentials

Why do we say there is an overall negative charge on the intracellular side of the plasma membrane at rest, and an overall positive charge on the extracellular side when both potassium and sodium are ...
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What is the equation and mechanism of Hopkins-Cole Test reaction?

The Hopkins-Cole reaction or glyoxylic acid reaction, is a chemical test used for qualitative detecting of tryptophan in protein solutions. tryptophan + glyoxylic acid + sulfuric acid > violet ...
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is a-keratin a fully functional protein?

is a-keratin before it coils with another polypeptide, makes chains, and build intermediate fillaments a fully functioal protein? I mean, is the single monomer of a-keratin a protein or it has to ...
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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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White residue from ginger juice

I’ve been juicing some ginger by grating it and pressing it (by hand). A white residue collects at the bottom of the liquid. What is this?
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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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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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Why is chloride ion classed as a cofactor for amylase rather than as a coenzyme?

I am provided with the two following statements and have to prove which is true and which is false. $\ce{Cl-}$ acts as a coenzyme for amylase $\ce{Zn^2+}$ acts as a prosthetic group for carbonic ...