10
votes
Accepted
Can fats be composed of fatty acid esters other than triglycerides?
Indeed there's nothing stopping such molecules from existing. In fact it is possible to make dendrimeric polyol polyesters such as Olestra, where sucrose (a disaccharide containing eight free hydroxyl ...
- 29.2k
8
votes
Accepted
why is alpha-linolenic acid "alpha"?
The nomenclature of these acids seems to be a historical convention.
Alpha-linolenic acid was first isolated in pure form in 1909 by Ernst Erdmann and F. Bedford (Ref.1). The following passage from ...
- 288
8
votes
What makes trans fats more harmful than saturated ones?
First of all, it's important to distinguish between the types of fatty acids that may form the cell's membrane:
Note that both cis- and trans-fatty acids are unsaturated, the difference being the ...
- 1,410
5
votes
Is omega 3 a specific fatty acid?
There exists a range of ω-3 acids.
Fatty acids are made of a chain of carbon atoms (generally linear), with a carboxylic acid at one end. Usually the carbon atoms are linked with a single-bond, but ...
- 645
4
votes
Accepted
How much lipoic acid is contained within octanoic acid?
Background
One lipoic acid molecule is enzymatically produced from one octanoic acid molecule in the mitochondrion or in the bacterium by the enzyme lipoyl synthase (LipA).
To get there, first the ...
- 1,379
4
votes
Why are fats glossy?
Reflected light (gloss) is a maximum when the angle of observation is equal to the angle of incidence: https://en.wikipedia.org/wiki/Gloss_(optics). The image shows reflection from a plane surface ...
- 14.3k
3
votes
Biochemically speaking, why aren't the cell membranes of eukaryotic, multicellular organisms made of more heat-resistant stuff?
The evolution of organisms tends to drive out features that are not necessary for survival
The right question to ask here is: why would they be heat resistant?
The key features of most organisms have ...
- 37.8k
3
votes
Why are fats glossy?
The equation for reflection ($\mathrm R_0$) of interfaces of clear mediums is given by:
$$\mathrm R_0 = \left[ \frac{n_1 - n_2}{n_1 + n_2} \right] ^2$$
where $n_i$ is the refractive index of its ...
- 12.7k
2
votes
What happens when C17H35COO-, a soap, reacts with an acidic solution?
Actually, soap in acidic water just means reactions with the hydrogen ions in acid and whatever other element in the acids is not a matter to be concerned about. For example, sodium stearate $\ce{...
- 21
2
votes
Accepted
Which is better: iodine number or bromine number?
Bromine number (and Bromine Index) are based on theoretically good chemistry; however, that is where their virtues end. If these tests are run according to the current ASTM procedures, you are ...
- 36
2
votes
fatty acid vs polyethylene
I agree with @Mithoron's earlier comment that even if these two types of compounds are somewhat similar in structure (e.g., they both consist of long aliphatic chains) they are not exactly alike. If ...
2
votes
Accepted
Uncertainty in measuring the mass of the palm oil and the base in saponification
It would effect primarily the mass obtained (yield) and probably the quality, too, but that depends on how you measure this. Given that you use some procedure to purify your crude product that is ...
- 44.4k
2
votes
fatty acid vs polyethylene
I disagree with the other answers that polarity is the most important. I think the degree of polymerization is the most important difference in common fatty acids and common polyethyelenes.
The DP of ...
- 22.6k
2
votes
Are all fatty acids monocarboxylic acids?
You are asking two separate questions.
Not all fatty acids are typically found in fats and oils (common name for storage lipids, which is also somewhat a common name...) Identifying fatty acids ...
- 41
1
vote
Can glycerol in substituted natural fats be a monomer according to European REACH Regulation?
polymer: means a substance consisting of molecules characterised by the sequence of one or more types of monomer units. Such molecules must be distributed over a range of molecular weights wherein ...
- 44.6k
1
vote
Accepted
Gelatination of solution in saponification
Sodium stearate is not very soluble in water (above about 2%, it becomes viscous but not a firm gel). Ethanol can reduce the viscosity at first, but sodium stearate is not soluble in ethanol either, ...
- 14.3k
1
vote
Accepted
Where do the chloride ions go during saponification precipitation?
Adding a concentrated $\ce{NaCl}$ solution to a soap solution produces the precipitation of sodium alkanoates (indeed it is a mixture of alkanoates and alkenoates). This is a consequence of the law of ...
- 30k
1
vote
Does glycerin dissolve in fat?
Glycerol (glycerin) is polar molecule with three hydroxy groups. Fats are tri-esters of glycerol and very long-chained fatty acids, and hence relatively non polar molecules. Thus it is safe to assume ...
- 42.1k
1
vote
How much lipoic acid is contained within octanoic acid?
Fatty acids that are purified from biological sources are typical isolated from oils or fats, both of which are comprised of triglycerides. That is, there are three fatty acids attached to a single ...
- 10.4k
1
vote
fatty acid vs polyethylene
The main difference is the polarity. Alcanes and polyethylene are nearly not polar, because both $\ce{C}$ and $\ce{H}$ have nearly the same electronegativity. Fatty acids contains the group $\ce{-COOH}...
- 30k
1
vote
Accepted
Transformation of fats in presence of alcohol
Let's just not forget that we're dealing with cooking, i.e., ridiculously complex chemical composition.
The main factor here is temperature.
Alcohol (Ethyl Ethanol) evaporates, as Ivan said. ...
1
vote
Why are trans fats worse than saturated fats?
In my chemistry lab, one of the teaching experiments at my university involved nickel catalysed isomerisation of an alkene, as nickel is also the catalyst for hydrogenation.
This could explain why ...
- 11
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