15 votes
Accepted

What animal has fat with the highest energy density?

In both humans and animals, the body fat stores appear as triglycerides, which can be composed of different fatty acids, but they all have about 9 kilocalories per gram (USDA). There can be different ...
Jan's user avatar
  • 8,079
11 votes

Is a fatty acid a polymer?

In the IUPAC Gold Book, IUPAC defines a polymer as follows: A molecule of high relative molecular mass, the structure of which essentially comprises the multiple repetition of units derived, ...
Armatus's user avatar
  • 7,660
10 votes

Is a fatty acid a polymer?

Fatty acids are usually not considered polymers. From a biological viewpoint this is simply because there is only a very limited set of chain lengths that exists in nature (~2-20 or so) and also even ...
Nicolai's user avatar
  • 4,391
9 votes
Accepted

Is palmitic acid really that dangerous?

Let's first clarify some concepts. Free fatty acids, including palmitic acid, are not present in animal tissues (or in the diet) to any large extent; they are esterified with glycerol to from ...
Roland's user avatar
  • 5,705
8 votes
Accepted

What is the thinking behind the naming of arachidonic acid?

There are finitely many letters and possible combinations of them making words, and many many things to be named. Inevitably, some of the words will be similar or even homonyms. To me, having some ...
Domen's user avatar
  • 1,932
6 votes

Why do cell membranes have a lipid bilayer instead of a monolayer?

Why Bilayer and not a Monolayer Lipid monolayer vesicles are possible as you mentioned (for example micelles). However, you have to understand that the cellular interior i.e. the cytoplasm, is ...
WYSIWYG's user avatar
  • 35.6k
6 votes
Accepted

Why do the mRNA vaccines for COVID need special lipids?

Lipid nano particles are bound by serum proteins, the opsonins which are part of the innate system and are subsequently eliminated from the body by uptake through macrophages. Binding PEG to the ...
Chris's user avatar
  • 51.6k
5 votes
Accepted

What is the lipid membrane of SARS-CoV-2 made of?

I don't know if this questions has been studied in detail even for SARS, let alone SARS-CoV-2. As noted in a comment by reuns, the virus lipid envelope is most likely derived from that of the ...
the gods from engineering's user avatar
5 votes
Accepted

Do lipids have a monomer or not?

No, classic lipids are not considered polymers. Organic chemists have specific names for aliphatic chains of specific sizes, so there‘s no need for polymer terminology. For example, fatty acids are ...
markur's user avatar
  • 1,769
4 votes

What do sphingolipids do in humans?

It turns out sphingilipids have many functions in humans, many of which might still remain unknown. I will discuss here only the general, known functions of sphingolipids, not about specific ...
another 'Homo sapien''s user avatar
4 votes

Types of structures formed by various types of lipid molecules

PCs are lipids with large head groups, so are more of a cylindrical shape, as a result, they tend to form flat bilayers. PE is a lipid with a small head group, so is in a conical shape. However, they ...
biologist_Jaishree's user avatar
4 votes
Accepted

How fast do lipids on the inside and outside of a lipid bilayer exchange?

A cursory search seems to show at least a few papers using sum-frequency vibrational spectroscopy to measure rates of flip-flopping/transverse diffusion in lipid bilayers. This paper in particular (&...
Spencer Guo's user avatar
3 votes
Accepted

Why is hydrogen to oxygen ratio used to compare energy storage efficiency?

Answer In my opinion: The original poster’s overall interpretation of the statement in the article (as reported) is most likely correct. Problems with original statement Although the statement may ...
David's user avatar
  • 25.7k
3 votes
Accepted

Protein rafts over the Phospholipidic bi-layer

These conglomerations of proteins, glycolipids, and cholesterol are usually called lipid rafts. (Google Scholar shows 84,000 hits for that term, vs. 400 hits for "protein raft".) Here is a diagram ...
mgkrebbs's user avatar
  • 9,054
3 votes
Accepted

Why is glycerol the backbone of fat?

Chance should always be high on our list of explanations of why the history of life turned out in some specific way. As James A. Coffman has described, there are a couple of different notions of ...
Galen's user avatar
  • 1,045
3 votes
Accepted

Are there biochemical differences between the cell membranes of prokaryotes and eukaryotes?

There are differences. (Except mitochondrial eukaryotic membranes, which are indeed similar to bacterial membranes! (reviewed in van Meer et al., 2008)). First, bare in mind that it is thought that ...
James's user avatar
  • 11.3k
2 votes

Synthesis of Fatty Acids Longer than 16 Carbons

Short Answer: Yes. Long Answer: See this article: The diagrams presented show how fatty acids are synthesized in microorganisms and list the enzymes found in Escherichia coli. These reactions are ...
another 'Homo sapien''s user avatar
2 votes
Accepted

Apolipoprotein B48 and fat storage

Fatty acids originating from chylomicron triacylglycerol are delivered mainly to adipose tissue, heart, and muscle (80%), while ~20% goes to the liver. - source: Harper's illustrated ...
Sikander's user avatar
  • 338
2 votes
Accepted

Are all/most/any membranes comprised of lipids from the smooth ER?

It sounds like we're mainly interested in phospholipids here, as they're the main component of cell membranes. Since your question didn't specify, we'll talk about Bacteria/Archaea and Eukarya ...
Dubukay's user avatar
  • 808
2 votes
Accepted

Can emulsion test be used to detect phospholipids?

Yes, the test will still work. And you are correct about the phospholipid's process of forming 'circles' in water. The reason the test still works is because alcohol increases the permeability of the ...
Reece's user avatar
  • 213
2 votes

Why do the phosphatidylserine and Phosphatidylethanolamine favor one side of the cell membrane?

There seem to be two questions here. The poster seem to know the answer to the first question — that in the title — that their shape fits into one or other side of a curved membrane. So I would ...
David's user avatar
  • 25.7k
2 votes
Accepted

Does destroying a virus envelope make the virus inactive?

Enveloped RNA viruses will get inactivated quickly without a membrane. RNase is a ubiquitous enzyme that would quickly digest any exposed genetic material. Via https://www.neb.com/tools-and-resources/...
Alex Reynolds's user avatar
2 votes

Are there any drugs that target the lipid envelope of viruses?

The lipids in the viral envelope come from chunks of the host cell membrane. Therefore, something targeting those lipids is unlikely to be virus-specific, and not suitable for use in a living animal. ...
Bryan Krause's user avatar
  • 45.7k
1 vote

Why is glycerol the backbone of fat?

Summary To attempt to explain why organisms evolved with a particular molecule performing a particular function it is not sufficient to consider the suitability of the molecule for that function and ...
David's user avatar
  • 25.7k
1 vote

Does Rough ER (RER) produce phospholipids?

The endoplasmic reticulum (ER) is one of the largest continuous membrane bound organelle of the cell. The rough ER and smooth ER share the same membrane and some membrane proteins can diffuse ...
Dr. H. Lecter's user avatar
1 vote

Which lipoprotein has the highest protein content?

LDL has the higher protein content than HDL. LDL consists of Apo B48 and Apo B100. These are proteins with higher molecular weights between 250 kDa to 550 kDa as compared to other apoproteins. And ...
Twinkle Sheen's user avatar
1 vote
Accepted

Lipid packing defect

It would help if you could delimit in which cellular of molecular context you would like to understand packing defect, for exemple during vesicular budding or lipid droplet biogenesis. In the larger ...
Dr. H. Lecter's user avatar
1 vote

Is a fatty acid a polymer?

I've never heard of anyone consider fatty acid to be a polymer. I'm not a biologist, but all of my research is on polymers-specifically paints and coatings. Fatty acids are often used in the ...
Robert F B's user avatar
1 vote

How are Mono and Diglycerides metabolized without the Free Fatty Acids of Triglycerides?

Inside the intestinal lumen, di- and triacylglycerol are hydrolysed to free fatty acid and monoglyceride by lipase. These diffuse through the plasma membrane of enterocyte where they will used to ...
Eliane B.'s user avatar
  • 1,145

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