Lipids: Oils, Waxes, and Biosynthesis

Podcast

Play an AI-generated podcast conversation about this lesson

Download our mobile app to listen on the go

Get App

Questions and Answers

What is the key distinction between fixed oils/fats and waxes in terms of chemical composition?

Waxes contain both glycerol and long-chain fatty acids, while fixed oils/fats only have fatty acids.
Fixed oils and fats are derived from animal sources, whereas waxes are plant-based.
Fixed oils and fats contain glycerol, while waxes contain higher molecular weight alcohols. (correct)
Waxes are composed of saturated fatty acids, while fixed oils/fats are unsaturated.

Which of the following is a characteristic of oils obtained by expression in hydraulic presses?

Solvents are typically used in the 'cold-pressed' extraction method.
Oils extracted with heat are known as 'virgin oils'.
Oils extracted without heat are known as 'cold-pressed oils'. (correct)
Heat extraction always results in a lower quality oil with higher free fatty acid content.

What does a high saponification value indicate about a substance?

A large number of milligrams of potassium hydroxide are required to neutralize the free acids and saponify the esters. (correct)
A high degree of unsaturation.
A large amount of free fatty acids.
A low melting point.

How is the biosynthesis of fatty acid moieties primarily carried out in living organisms?

A series of reactions involving enzyme complexes, ATP, NADPH₂, Mn++, and carbon dioxide. (B) Signup and view all the answers

In the context of lipid biosynthesis, what is the role of malonyl-CoA?

Its malonyl portion serves as the source of the 2-carbon biosynthetic units. (D) Signup and view all the answers

What is the purpose of hydrogenating fixed oils?

To convert unsaturated glycerides to saturated glycerides, resulting in semisolid fats. (C) Signup and view all the answers

How are sulfated or sulfonated oils produced, and what is a key requirement during their production?

By reacting sulfuric acid with the oil while maintaining low temperatures. (B) Signup and view all the answers

Castor oil is obtained from Ricinus communis. What is a notable characteristic regarding the seed?

The seed contains ricin, a toxic lectin. (C) Signup and view all the answers

Which of the following is a grade of olive oil produced by extracting the pulp with carbon disulfide?

"Sulfur" oil (C) Signup and view all the answers

What accounts for the excellent stability of sesame oil?

A phenolic constituent, sesamol. (D) Signup and view all the answers

For what purpose is ethodized oil used?

As a radiopaque diagnostic aid. (D) Signup and view all the answers

Why are the seeds of Theobroma cacao roasted?

To lose water and develop their characteristic odor and taste. (B) Signup and view all the answers

What is a primary use for cocoa butter in pharmaceuticals?

As a suppository base. (B) Signup and view all the answers

Which of these is a key characteristic of lanolin that makes it useful in topical applications?

It is water-absorbable. (D) Signup and view all the answers

How are Stearic acids usually obtained?

Hydrolysis of fats or oils. (B) Signup and view all the answers

What advantage do Isopropyl myristate and isopropyl palmitate have over naturally-sourced vegetable oils?

They are less oleaginous and less prone to oxidation. (C) Signup and view all the answers

What is the primary method for obtaining undecylenic acid, a common ingredient in anti-fungal products?

Pyrolysis of ricinoleic acid from castor oil. (B) Signup and view all the answers

Besides being an emollient what other property makes cetyl alcohol useful in pharmaceutical preparations?

Emulsifying Aid. (B) Signup and view all the answers

What is liquid wax, as opposed to triglycerides?

Jojoba oil (B) Signup and view all the answers

What is the primary use for yellow wax?

A stiffening agent in ointments. (D) Signup and view all the answers

What has been found in human semen could produce contraction and relaxation of the human uterus?

Prostaglandins (C) Signup and view all the answers

Why is prostaglandin E1 used over other kinds of prostaglandins?

Inhibits the effects of platelet aggregation (D) Signup and view all the answers

Which statement accurately reflects the relationship between acids and iodine number?

Iodine number measures degree of unsaturation, while acids help quantify the amount of free fatty acids present. (D) Signup and view all the answers

An analysis reveals a lipid sample rich in saturated long-chain glycerides at room temperature. Which extraction method most likely separated this sample?

Rendering at normal temperatures. (C) Signup and view all the answers

Following lipid extraction of peanuts, the remaining "peanut oil cake" finds a particular secondary application--what is it?

High-value livestock food by-product. (D) Signup and view all the answers

Flashcards

Lipids (fixed oils, fats, and waxes)

Esters of long-chain fatty acids and alcohols.

Fixed Oils

Liquid at normal temperatures; they are a type of lipid.