Questions tagged [lipids]
For questions related to lipids including but not limited to fats and their derivatives in regards to chemistry.
36 questions
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How to understand the contour plot of NMR data of peptide reconsituited into mechanical oriented DMPC membrane?
I need help understanding the contour plot I mentioned. I have two questions:
How do the authors relate the topological restraints to the theoretical model? As I understand it, the tilt vs. pitch ...
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why is alpha-linolenic acid "alpha"?
I'm learning about how fatty acid names are formed. In the process, I noticed a molecule called alpha-linolenic acid. There's a similar molecule called linoleic acid. Both have 18 carbons, but alpha-...
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Aliphatic alcohol analysis in capillary gas chromatography
4.5. Standard solutions of trimethylsilyl ethers of aliphatic alcohols from C20 to C28.
They may be prepared from mixtures of pure alcohols at the time they are required for
use.
Reference solution ...
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Are lipid membranes destabilized by aligning so many negatively charged phosphates in close proximity?
From my understanding, lipid membranes in biological systems are made mostly of phospholipids, which have a hydrophobic chain region and hydrophilic head group containing a phosphate. In the membranes,...
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What is the mechanism of Salkowski reaction of сholesterols?
I recently came across the Salkowski reaction of cholesterols. Cholesterol in chloroform is treated with concentrated sulfuric acid. A positive test exhibits two distinct layers, the upper chloroform ...
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Why do the two layers of a phospholipid bilayer stick together?
Every answer I can find about why phospholipids form a bilayer says the same thing: hydrophilic heads associate with water, hydrophobic tails do not, so they arrange themselves with heads facing ...
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Biochemically speaking, why aren't the cell membranes of eukaryotic, multicellular organisms made of more heat-resistant stuff?
TL;DR: there are lipids out there that are more heat-resistant than those in current cell membranes, yet current cell membranes don't have them. Why?
I've cobbled together various miscellaneous ...
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Can Amphotericin B cross a lipid bilayer membrane in its zwitterionic form when it is loaded in the aqueous core of a liposome?
Can Amphotericin B cross a lipid bilayer membrane in its zwitterionic form when it is loaded in the aqueous core of a liposome? Or must it be uncharged in order to cross the lipid bilyer membrane of ...
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Why is oil solubility improved in solvents at higher temperatures?
This is in the case of extracting plant oil using a solvent extraction method for the purposes of biodiesel production.
In a paper, it is stated that increased oil yield may be due to the 'increase in ...
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DIY lipid nanoparticles
I, and a number of friends, take a bunch of supplements that are polyphenols and often flavin-oids, -ols or -es; also numerous carotenoids. Examples include quercetin, luteolin, fisetin, curcumin, ...
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Why polysaccharides are not considered as lipids? [closed]
It is mentioned in my textbook that all lipids have one common trait which defines them :they are insoluble in water;they are hydropohic.
I want to ask ,since polysaccharides are also insoluble in ...
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How much lipoic acid is contained within octanoic acid? [closed]
As I understand it, lipoic acid is synthesized from octanoic acid:
Lipoic acid is synthesized de novo in mitochondria from octanoic acid, an 8-carbon fatty acid (C8:0), bound to the acyl-carrier ...
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Why is a drop of chloroform stretched/pulled apart on a water surface?
I distributed drops of chloroform (with a lipid in them) on water (in a Langmuir-Blodgett trough). The chloroform drops form a layer on the water (so that the lipids are distributed on the water ...
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Prostaglandin Nomenclature
Prostaglandins are lipid substances derived from fatty acids, which act as powerful biochemical regulators.
In Wade's Organic Chemistry, they indicate that there are several families of ...
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Fat polymerization vs hydrolysis and temperature change
I have an experiment on fats that I have to do in a few hours and I am very lost between fat/oil (lipid) polymerization due to high temperatures and hydrolysis. It appears that both result in the ...
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Can you lower the alcohol concentration of a drink using vegetable oils?
The log POW of ethanol is −0.18 according to Wikipedia, i.e. in a two-phase system ethanol would preferrably accumulate in the aqueous phase, but not by much.
Suppose I wanted to lower the alcohol ...
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Techniques to extract lipids
I am planning an experiment on how to isolate casein and part of the process involves removing any lipids that may still be in it after filtering the precipitated casein out of the milk. I have read ...
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What kind of plastic is (really) safe to store vegetable oil?
Storing colza or olive oil in a plastic bottle might be risky since the oil can leach out phthalates and BPA (and others molecules?).
Some manufacturers sell "phthalates and BPA free bottles", but ...
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Is flour or baking soda really suitable for extinguishing grease fires?
I think most have heard the advise that you should put flour (or baking soda) on a grease fire to absorb the oil before. While this is certainly better than using water, I'm skeptical.
For starters ...
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Why would diclofenac have a higher skin permeability when formulated as diclofenac epolamine rather than diclofenac sodium?
There is a suggestion on the literature that the formation of ion pairs creates a permeation enhancement.
Usually only non-ionised compounds penetrate the skin.
Is it possible that the conjugate ...
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What happens to a quaternary ammonium cation at a pH above its pKa?
I am working with a lipid and I have firm reasons to believe that its pKa is around 8. This lipid is a cationic lipid where the nitrogen is a quaternary amine with two lipid chains and two methyl ...
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What Makes Oils Feel Dry or Oily? [closed]
Simple question with a complex answer, certainly:
Why do some oils feel "dry," while others feel "oily"? Is the feel directly related to C-chain length, or hydrogenation, active groups, or something ...
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Could detergents dissolve cell membranes?
Animal cells have a lipid membrane and detergents are great at emulsifying lipids. Yes, there are proteins, cholesterol and other numerous substances in the lipid bilayer, but the lipids make up the ...
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Are triglycerides macromolecules?
I've previously been taught that triglycerides are macromolecules. However, a current professor of mine gave the definition of macromolecules as "polymers of covalently linked monomers". Since, ...
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How do water based solutions (cream, gels) etc permeable through hydrophobic skin? [closed]
Most skin care products or the sort are oily, lipid based.
Our skin is hydrophobic. I reckon the reason is to be easily permeable through the skin.
So how do these skin care or any products which are ...
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Why are plastics lipophilic?
My wife prepares lunch for me every morning. After eating it on my desk, I typically wash the lunchbox and utensils in the company's kitchen.
I have noticed that it is very difficult to remove the ...
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How are phosphoglycerides different from phospholipids?
(Currently studying high-school Biochemistry)
I'm unable to distinguish between phospholipids and phosphoglycerides from their "definitions" (Courtesy: Wikipedia)
On phospholipids:
Which suggests ...
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What happens during oxidative and hydrolytic rancidity of fats?
I understand that when lipid molecules - triacylglycerol - are hydrolysed, the fatty acids 'break' off from the glycerol backbone. And when fatty acids oxidise, these in turn can break into smaller ...
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How well can triglycerides be resolved using TLC?
The only part of triglycerides that significantly interacts with a TLC plate are the ester moieties which are present in all triglycerides. Other than that, they do not differ much, except in mass (...
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What is the significance of Sphingolipids in human?
I want to know the significance of sphingolipids in human. I have learnt that sphingomyelin is the most significant type of sphingolipid in human. Also that the sphingomyelin serves as a structural ...
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Is it known for sure that bases feel slippery because of the production of soap/surfactant?
Discussion around the question Why does bleach feel slippery? has started me thinking about the saponification explanation for the slippery feeling of basic solutions.
According to Wikipedia:
...
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How can I know if there is a phospholipid (phosphatidylcholine) in a solution?
I have a solution which probably contains a phospholipid (phosphatydylcholine), I would like to know if there is an easy method to show the presence of the phospholipid.
I came across TLC, but I ...
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Do unsaturated fatty acids with an odd number of carbons exist?
Our teacher asked us about fatty acid C21:3.
Does this fatty acid even exist?
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Mechanism Permitting Proton Sponge Effect
The proton sponge effect is utilized as a drug delivery method to release contents packaged in micelles (usually coated in PEG or another protective polymer) into the cytoplasm of a cell after being ...
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Are triglycerides soluble in polar solvents?
In my textbook it is said that they are soluble in non-polar solvents (which makes sense), but also soluble in polar solvents (halogenoalkanes and some ethers like ethoxyethane) It is said that the ...
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What is the common denominator of all the lipids?
I've read the lipids article on Wikipedia, but I couldn't understand the answer for my question and I'll explain why.
In biochemistry we have monomers and polymers while the monomer is the basic ...
