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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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glycogenesis, glycogenolysis and weight gain or loss

I am under the impression (from dietary websites) that when excess serum glucose is stored as glycogen, body weight is increased and the reverse: when glycogen is converted to serum glucose, body ...
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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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What do halophiles eat?

We all know that halophiles can survive salt environments and all that, but what do they really eat? Do they consume the salt in their habitat?
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Difference between Amylopectin and Amylose

I was reading about the structure of starch and found out that it's made up of amylose and amylopectin. In amylose, all the glucose molecules are joined by ⍺-1,4 glycosidic bonds. The structure of ...
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Light/Heavy Isotopes in Living Organisms

I was wondering, why are lighter isotopes (e.g. carbon-12 as opposed to carbon-13) preferentially used by life on Earth? Is their increased stability the only factor? Thanks in advance!
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Why are plants unable to take up Phosphorus directly in their organic form like Phytic Acid?

I am researching acquisition strategies of phosphorus by decidious trees. I am reading a lot that plants take up nutrients as their inorganic form. In the case of P according to literature this is ...
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38 views

Glycine and Hydrogen Bonding

Is glycine’s side chain a good H bond donor (only has one H as side chain).
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1answer
51 views

How can two biological sequences be anything but homologous?

If we consider homology between two nucleotide sequences as a yes/no answer to whether they have shared a common ancestral sequence, then given that all life share common ancestry and sequences are ...
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10 views

Meting temperature of PCR products and product expected size

I know the Melting temperature of my primers but I would like to know if the melting temperature of my product match with the melting temperature I get in the melting curve when doing a qPCR, in order ...
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Chimera vs whole animal pluripotency test (Stem cell)

I'm studying about stem cell about testing whether a cell is pluripotent by various methods including by embryoid body, teratoma, chimera and more stringent one, whole animal. I just don't really get ...
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1answer
48 views

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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What truly defines an asymmetric carbon atom?

We iust learned about symmetric and asymmetric carbon atoms today in class. I understand that an asymmetric carbon atom has four different types of atoms bonded to it. What I don't understand is why ...
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Possibility for artificial glycolysis outside cell & cytoplasm [on hold]

What will happen if you add glucose and hexokinase to non living medium (eg. just oil or water)? [Assuming that the hexokinase can convert glucose to G6P within the normal cytoplasmic environment]. If ...
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How do molecular biologists determine biochemical pathways?

I'm new to this community, so hopefully this is the right place to ask this question. I know my question is really general, but in all of my biology courses we are merely taught the chemical pathways ...
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Coacervater were more like Viruses or Cells?

The answer considers them as first formed living cells as they were precursor of life. But they had no lipid bilayer nor any cellular organization, shouldnt they be more like Viruses ,or like Prions ...
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1answer
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Protein Pathways, Superfamilie, Function database/website?

I'm going trough some old data - but I'm running into this problem that all website we used use is not existing anymore. What I have is a very long list of proteins with accession number (refSeq from ...
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1answer
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Where can I find resources of the biological processes occurring after death of a mammal at various temperatures?

Using google I usually end with results in cell death. I found some layman articles, but that does not help. My main interest is the brain part.
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Is hydroxyproline an amino acid? (Classification question)

So I know that hydroxyproline is created from proline via hydroxylation as a post-translational modification. I also know that proline is considered an amino acid. However, once you hydroxylize it, ...
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How plausible is it that pesticides and mosquito spraying is affecting insect populations?

I live in Massachusetts and I notice that there are a lot fewer bugs than when I was a child. 40 years ago if you drove around for 4 or 5 hours in the summer the grill of your car would collect a ...
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1answer
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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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1answer
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Why do crocodiles have a high concentration of lactic acid in their blood?

Crocodilians have high concentration of lactic acid in their blood. This is the cause that prevents them from prolonged intense activity, since prolonged intense activity causes the muscles to secrete ...
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Can Molisch test be used to separate monosaccharides from polysaccharides? [migrated]

Do the results of Molisch test on monosaccharides have any differences with when it's done to disaccharides or polysaccharides?
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0answers
35 views

Can low melatonin levels and/or LED lights cause or exacerbate macular degeneration?

I have two questions that may or may not be interconnected. My first question is: Does melatonin prevent macular degeneration? Could low melatonin levels (caused by blue-rich light exposure in the ...
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1answer
49 views

What does 'half life' of a protein mean?

Why do we use the term 'half life' for proteins? Here is a link to some information regarding this question, but I am unable to infer it.
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Acute calculous cholecystitis

The action of mucosal phospholipases hydrolyzes luminal lecithins to toxic lysolecithins. The normally protective glycoprotein mucus layer is disrupted, exposing the mucosal epithelium to the direct ...
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2answers
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Why are the first and last amino acids of an alpha helix not hydrogen bonded?

I am studying protein structures and in alpha helix I found out that one amino acid residue's carbonyl oxygen is linked to the nitrogen of amino group of 4 residues ahead.. However the first and last ...
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2answers
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Why don't phosphatases both add and remove phosphate groups if enzymes catalyze reactions in both directions?

We know that Phosphatase is a type of enzymes that removes a phosphate group. Why can't phosphatases add a phosphate group if we know that all enzymes reactions are reversible ?
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Proline flexibility

I was reading about the role of proline-rich domains in proteins. There seem to be two schools of thought. One is that proline has 2 degrees of freedom instead of 4, making it more rigid. This makes ...
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1answer
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What is the source of the fat in adipose tissue?

I have heard the opinion that all of it comes from de novo lipogenesis of carbohydrates, but I'm skeptical. Is there evidence either way - either that dietary fat definitely gets stored in the adipose ...
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How hypoxia causes increase in intracellular $Ca^{2+}$?

Ischemia can cause depletion of ATP inside cell which can affect the efflux of $Ca^{2+}$ via energy dependent calcium pumps. This may (How?) cause increase in $Ca^{2+}$ ions intracellularly (Effect of ...
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Should plants absorb nitrogen in a linear fashion - if not why?

I did an experiment that measured the change in concentration of nitrate overtime (in the water of hydroponically grown tomato plants) and the results don't seem to make sense. The concentrations as ...
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1answer
35 views

Synthesis of adenosine diphosphate? [closed]

Where does the ADP come from? As in before ADP was made from ATP and visa-versa how is it conceived that they appeared in nature?
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37 views

Bird vs Fish Encounter?

Visiting a beach at the ocean, I recently saw a Great Blue Heron dive and catch quite a spiky/large (and colorful! I think it was called a sculpin) crosswise in it's bill. It appeared, potential meal ...
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can “Pandanus amaryllifolius”[used in cooking] become poisonous if grown near drainage

how do they absorb wastes and become not suitable for eating
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Soybeans' bitter taste

What specific substances cause the bitter taste of the cooked soybeans? Is there a way they can be removed, except cooking?
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Why is the macromolecular composition of a human cell seemingly hard to find?

I am trying to find a 3D rendering or list of molecules by volume in a cell (originally I was searching for human, but I'll take any at this point!). I understand the open-endedness of the question: ...
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Young family members to learn genetics - Amino Labs? [closed]

I'm an engineer but want to learn about biology with a niece and nephew who are early teens. I saw Amino Labs (https://amino.bio/) and thought because I work a lot with my hands, doing hands on ...
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hydrogen peroxide vapour sterilization vs hydrogen peroxide plasma sterilization which is better?

hydrogen peroxide vapour sterilization vs hydrogen peroxide plasma sterilization which is better?can i use a ultrasonic mist maker to make hydrgen peroxide vapour?Can use the vapour in a glove box?
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Why is serum ferritin elevated in Chronic disease anemia?

I've been searching the reason of this but I've been not able to find it.
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1answer
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When in Ampicillin degraded (gone) in liquid TB-media? Concerns about selectivity

Question: Specifically regarding Ampicillin; When growing cells in TB (terrific broth) for protein expression - when should I expect the ampicillin to be gone due to degradation by b-lactamases? (and ...
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1answer
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How would a medication cause a one to maintain a different weight?

This isn’t really a medical question, I’m just really curious about this. I was maintaining weight A and then started taking a medication that brought me to weight B. While on the medication, I ...
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About The Selfish Gene Book - How Replicators Molecules forms duplicates?

I was reading The Selfish Gene. In the 2nd chapter - "Replicators" I read: Think of the replicator as a mold or template. Imagine it as a large molecule consisting of a complex chain of various ...
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188 views

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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Why the same complex compounds occur and play different roles in different organisms?

For instance, in humans estrogens function as sexual hormones, but they also occur in many plants, where obviously their role is totally different. Some compounds, such as psilocybin have psycho-...
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What is the actual charge of NAD at physiological pH (roughly 7)?

I am curating a metabolic model using CobraPY. Mass imbalances often occur in equations. Many different websites e.g. Kegg, ModelSEED, PUBCHEM, etc. have differing charges and formulas for compounds. ...
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Neuroscience - A neuron with two types of synapses (electrical and chemical) at the same time

I learn that the nerves from the Peripheral Nervous System can carry signals from and to other organs of the body. I'm wondering if A Single Nerve carries 1) Only chemical signals 2) Only physical ...
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How to calculate the Marker Index(MI) for a dominant marker such as RAPD and ISSR?

I am working in the genetic diversity analysis of a plant species and have used RAPD and ISSR markers. After scoring the data in a binary matrix, I am trying to find the marker index of the primers. I ...
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1answer
66 views

Michaelis-Menten equation; how to find the constants from enzyme activity experimental results?

I was wondering what the constants in the Michaelis-Menten equation actually mean in experimental data of enzymes. How do I process the data to find Km and Kcat? I did an experiment on catalase and ...
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What chemical effect does stress cause in the body that causes so many problems?

Mental discomfort, "stress", isn't a thing that in itself can cause physical problems in the body, yet again and again I see medical articles cite stress as a trigger for countless problems, usually ...
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1answer
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Pyruvate oxidation - where did the hydrogen come from?

As shown in the diagram above, NAD+ is reduced and becomes NADH by gaining two electrons Now, where did the hydrogen come from? In the diagram, pyruvate has 3 hydrogen, but it still has 3 hydrogen ...