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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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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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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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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 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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Dissociation of cell membrane proteins

Can peripheral membrane proteins be dissociated from cell membrane by changes in pH and ionic strength; if yes, why
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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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Bath Application of genistein

Some researches (for example, Kusaka & Sperelakis, 1995) use bath applications of genistein on cell cultures to see the various effects genistein has on the culture. I have seen in another source ...
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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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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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Can Luciferase utilize GTP as an energy source to breakdown luciferin?

Is there a difference in bioavailability of the energy from GTP compared to ATP? I want to know if luciferase can use GTP and, if it can, does the rate at which it can utilize GTP in the reaction ...
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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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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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Gaussian Network Model eigenvalues correspondence to mode frequencies [migrated]

I am in the process of setting up a coarse-grained Gaussian Network Model (Cα-atoms being representative of each residue) for normal mode analysis of proteins and would like to obtain the wavenumber/...
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How efficient would sulfuric blood be?

Just curious, how efficient at carrying oxygen--or other gases for that matter--would sulfur-based blood be?
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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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Could animal cell membrane be made of glycolipids instead of phospholipids?

I know that cell membrane contains lots of molecules that are not phospholipids, like cholesterol, glycoproteins and glycolipids. I was woundering what would happen if we just take all of the ...
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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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How can i confirm the native molecular weight, subunit composition as well as subunit molecular weight of a given protein? [on hold]

I have been given a homodimeric protien of 66000Da of MW. What techniques should i use and in which mannner to determine the the info asked?
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Can sugars/carbohydrates have 2 carbons?

Why can't $\ce{C2H4O2}$ be a carbohydrate monosaccharide?
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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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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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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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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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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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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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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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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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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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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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What is the minimal set of essential elements for known life?

In other words: what is are the sets of chemical elements of least cardinality which completely make up at least one known organism? All hits i have seen so far for "essential elements for life" are ...
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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 ...
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How much of dried microalgae is carbon by weight?

I am attempting to calculate the average concentration of elemental carbon per gram of dried freshwater microalgae for a climate change project. If it makes it to production, the algae will be grown ...
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Are unsaturated fats antioxidants?

Unsaturated fats contain double bonds like carotenoids (which is an antioxidant), and from my understanding, what makes carotenoid an antioxidant is that its double bonds allow it to undergo oxidation,...
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Is a fatty acid a polymer?

From my understanding, polymers are long chain molecules containing repeating units of monomers. For example, proteins are polymers called polypeptides with repeating units of (different) amino acids....
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Questions to protein folding

I have some questions regarding the process of Protein folding. These are the following: Are there existing Protein folding processes, where only a few seconds after completed folding a Protein ...
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Why is lemon juice a surfactant?

In this question on Physics SE, it is noted that pitchers containing lemon juice form foam when water is poured in to them from a distance. This is an easy effect to reproduce and many of us have ...
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Fruiting of trees — environmental stimuli and biochemical cascades

My question concerns fruiting of trees in general. However, I live in a tropical country (Philippines) where mango trees are ubiquitous, so I'll use it in stating my question. The question is about >...
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How can I detect the presence of the Bet v1 allergen (the allergen that causes oral allergy for almonds) in a sample of raw almonds?

I am a student and I want to conduct an experiment where I heat samples of the same type of raw almond at different temperatures and test the presence of the Bet v1 allergen (a protein allergen) in ...
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Chemistry of phosphodiester bond formation by DNA polymerase

As I'm teaching General Biology to my college students, I realized that I don't fully understand how a 3-P nucleotide like ATP is broken down to be incorporated into DNA during replication. How does ...
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When forming an enzyme-substrate complex in a spontaneous reaction, why free energy increases?

We ate food, and then food was digested into proteins, carbohydrates... Does not digestion break bonds within food macromolecules? and thus free energy decreases? why when looking to the curve we see ...
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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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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 ...