Lipids and Fatty Acids Overview
23 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

Which statement correctly describes saturated fatty acids?

  • They are water-soluble compounds.
  • They are always comprised of an odd number of carbon atoms.
  • They contain only single bonds along the length of the carbon chain. (correct)
  • They contain one or more double bonds in the hydrocarbon chain.

What is the energy value provided by 1 gram of lipids?

  • 11 kcal
  • 7 kcal
  • 9 kcal (correct)
  • 4 kcal

How are unsaturated fatty acids classified?

  • By the presence of a hydroxyl group.
  • By the number of double bonds present per fatty acid. (correct)
  • By their solubility in water.
  • By the number of carbons they contain.

Which of the following is an essential fatty acid?

<p>Linoleic acid (C)</p> Signup and view all the answers

In the numbering of carbon atoms in fatty acids, which carbon is known as the α-carbon?

<p>The second carbon from the carboxyl carbon. (B)</p> Signup and view all the answers

What is indicated by the symbol Δ in fatty acids?

<p>The site of unsaturation within the chain. (A)</p> Signup and view all the answers

When numbering fatty acid carbons from the omega end, what does ω9 indicate?

<p>The double bond occurs on the ninth carbon from the ω carbon. (B)</p> Signup and view all the answers

Which of the following fatty acids is typically saturated?

<p>Palmitic acid (A)</p> Signup and view all the answers

Which lipid is primarily a component of the cell membrane and contributes to its rigidity?

<p>Cholesterol (B)</p> Signup and view all the answers

Which of the following are classes of eicosanoids derived from arachidonic acid?

<p>Prostanoids and Leukotrienes (A)</p> Signup and view all the answers

What is the process called when triglycerides undergo hydrolysis with KOH or NaOH?

<p>Saponification (A)</p> Signup and view all the answers

Which of the following fatty acids is essential for the human body?

<p>Linoleic acid (B)</p> Signup and view all the answers

What type of lipid predominantly serves as a precursor for sex hormones and bile salts?

<p>Cholesterol (A)</p> Signup and view all the answers

Which of the following statements about rancidity is true?

<p>It releases hydrogen peroxide during the process. (B)</p> Signup and view all the answers

The basic structure of cell membranes is primarily composed of which arrangement?

<p>Lipid bilayer (A)</p> Signup and view all the answers

What is the common name for the monoenoic acid with 18 carbon atoms and one double bond?

<p>Oleic (C)</p> Signup and view all the answers

Which fatty acid is classified as ω3 and has six double bonds?

<p>Cervonic (B)</p> Signup and view all the answers

Which fatty acid is essential and categorized as ω6 with two double bonds?

<p>Linoleic (C)</p> Signup and view all the answers

In the classification of lipids, what distinguishes complex lipids from simple lipids?

<p>Complex lipids contain additional groups beyond the alcohol and fatty acids. (D)</p> Signup and view all the answers

Which of the following is NOT a characteristic of monoenoic fatty acids?

<p>They are always saturated hydrocarbons. (A)</p> Signup and view all the answers

Which fatty acid has 20 carbon atoms and is a key component of phospholipids in animals?

<p>Arachidonic (D)</p> Signup and view all the answers

What is the classification of fatty acids that have three double bonds?

<p>Trienoic acids (B)</p> Signup and view all the answers

Which family does the fatty acid γ-Linolenic belong to?

<p>ω6 (C)</p> Signup and view all the answers

Flashcards

Monoenoic acids

Fatty acids with one double bond.

Dienoic acids

Fatty acids with two double bonds.

Trienoic acids

Fatty acids with three double bonds.

Tetraenoic acids

Fatty acids with four double bonds.

Signup and view all the flashcards

Pentaenoic acids

Fatty acids with five double bonds.

Signup and view all the flashcards

Hexaenoic acids

Fatty acids with six double bonds.

Signup and view all the flashcards

Fats

Esters of fatty acids with glycerol.

Signup and view all the flashcards

Waxes

Esters of fatty acids with higher molecular weight alcohols.

Signup and view all the flashcards

What are lipids?

A large group of organic compounds that are generally insoluble in water but soluble in organic solvents like ether and benzene. They are crucial components of our diet.

Signup and view all the flashcards

What are fatty acids?

These molecules are characterized by their long hydrocarbon chains which end in a carboxyl group. They are a fundamental building block of lipids.

Signup and view all the flashcards

Describe saturated fatty acids.

These fatty acids have only single bonds between their carbon atoms, creating fully saturated chains.

Signup and view all the flashcards

Describe unsaturated fatty acids.

These fatty acids contain one or more double bonds along their carbon chains.

Signup and view all the flashcards

What are monounsaturated fatty acids?

They are characterized by the presence of only one double bond within their hydrocarbon chain.

Signup and view all the flashcards

What are polyunsaturated fatty acids?

These fatty acids have two or more double bonds within their hydrocarbon chain.

Signup and view all the flashcards

How are carbon atoms in FAs numbered?

In fatty acids (FAs), the carbon atoms are numbered from the carboxyl group (COOH) to the terminal methyl group.

Signup and view all the flashcards

What is the omega (ω) carbon?

The last carbon in the fatty acid chain is designated as the 'omega' (ω) carbon and is also known as the n-carbon.

Signup and view all the flashcards

Glycolipids

Lipids with a carbohydrate and sphingosine. Examples include glucocerebrosides, galactocerebrosides, and gangliosides.

Signup and view all the flashcards

Glucocerebrosides

A type of glycolipid that contains glucose.

Signup and view all the flashcards

Galactocerebrosides

A type of glycolipid that contains galactose.

Signup and view all the flashcards

Gangliosides

A type of glycolipid that contains multiple sugar units.

Signup and view all the flashcards

Lipoproteins

A type of complex lipid that is made up of protein and lipid. Examples include chylomicrons, very low-density lipoproteins (VLDL), low-density lipoproteins (LDL), and high-density lipoproteins (HDL).

Signup and view all the flashcards

Steroids

A type of lipid that contains the cyclopentano-perhydro-phenanthrene ring. The most abundant steroids in the human body are sterols, which have an alcohol group (–OH) attached to the steroid nucleus. Examples include cholesterol, ergosterol, bile acids, sex hormones, adrenal cortical hormones, and vitamin D3.

Signup and view all the flashcards

Cholesterol

A type of steroid that is the major sterol in the human body. It is a component of cell membranes and helps to give the membrane rigidity. It is also the precursor for all other steroids in the body, such as testosterone, estrogen, progesterone, vitamin D, bile salts, and corticosteroids.

Signup and view all the flashcards

Eicosanoids

A group of compounds derived from the 20-carbon polyunsaturated fatty acid arachidonic acid. They include prostaglandins, prostacyclins, thromboxanes, leukotrienes, and lipoxins.

Signup and view all the flashcards

Study Notes

Lipids

  • Lipids are a group of compounds related to fatty acids.
  • They are insoluble in water but soluble in fat solvents like ether and benzene.
  • Lipids are essential dietary components, providing high energy value (1g = 9 kcal), fat-soluble vitamins, and essential fatty acids.

Fatty Acids

  • Fatty acids are monocarboxylic acids with a long hydrocarbon chain.
  • Two main types: saturated and unsaturated.
  • Saturated fatty acids contain only single bonds in their carbon chain. Carbon atoms are fully saturated with hydrogen. Fatty acids in the human body contain an even number of carbon atoms (e.g., 4, 6, 8...).
  • Unsaturated fatty acids contain one or more double bonds in the carbon chain. They are further classified as monounsaturated (one double bond) or polyunsaturated (two or more double bonds). Carbon atoms are numbered starting from the carboxyl carbon (carbon number 1). Carbon atoms adjacent to the carboxyl carbon are called α, β, γ. The terminal methyl carbon is the ω or n carbon. The site of unsaturation is indicated by the Δ symbol. Δ9 indicates a double bond between carbons 9 and 10.

Saturated Fatty Acids Examples

  • Butyric acid (4 carbons)
  • Lauric acid (12 carbons)
  • Myristic acid (14 carbons)
  • Palmitic acid (16 carbons)
  • Stearic acid (18 carbons)
  • Arachidic acid (20 carbons)

Unsaturated Fatty Acids of Significance

Number of Carbon Atoms & Double Bonds Family Common Name
16:1 Monoenoic Palmitoleic
18:1 Monoenoic Oleic
18:1 Monoenoic Elaidic
18:2 Dienoic Linoleic
18:3 Trienoic γ-Linolenic
18:3 Trienoic α-Linolenic

Unsaturated Fatty Acids of Significance (Continued)

Number of Carbon Atoms & Double Bonds Family Common Name Occurrence
20:4 Tetraenoic Arachidonic Found in animal fats, important component of phospholipids in animals
20:5 Pentaenoic Timnodonic Important component of fish oils
22:6 Hexaenoic Cervonic Fish oils, phospholipids in brain

Classification of Lipids

  • Simple Lipids: Neutral fats, Waxes
  • Complex Lipids: Phospholipids, Glycolipids, Lipoproteins
  • Derived Lipids: Fatty acids, Glycerol, Steroids, some alcohols, fatty aldehydes, ketone bodies.

Steroids

  • Steroids are compounds containing the cyclopentanoperhydrophenanthrene ring.
  • Common steroids include cholesterol, ergosterol, bile acids, sex hormones, adrenal cortical hormones, and vitamin D3.
  • Cholesterol is a major sterol in the body, a constituent of cell membranes.
  • Cholesterol is a precursor for other steroids.

Eicosanoids

  • Eicosanoids are compounds derived from arachidonic acid.
  • Subgroups: Prostanoids, Leukotrienes, Lipoxins.
  • Prostanoids (e.g., prostaglandins) have significant physiological and pharmacological activities in the human body.
  • Leukotrienes cause bronchoconstriction and play a role in asthma.

Chemical Properties of Lipids

  • Saponification: Hydrolysis of TAG (triacylglycerols) with KOH or NaOH.
  • Rancidity: Hydrolysis and oxidation of unsaturated fatty acids in fats, due to atmospheric moisture and temperature, producing hydrogen peroxide, giving a bad odor and taste to the fats. Antioxidant prevent rancidity.

Cell Membrane and Cell Membrane Lipids

  • Cell Membranes are complex structures composed of lipids, proteins, and carbohydrates.
  • The basic structure of cell membranes is a lipid bilayer. Phospholipids form the bilayer, with their polar hydrophilic heads facing the aqueous environments (inside and outside the cell) and their nonpolar hydrophobic tails facing inward.
  • Phospholipids, Glycolipids and Cholesterol are important components of cell membranes, with Phospholipids containing choline being a notable example.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Related Documents

Lipids Chemistry 2024 PDF

Description

This quiz covers the essential concepts of lipids and fatty acids, focusing on their structure, function, and dietary importance. Learn about saturated and unsaturated fatty acids and how they differ in composition. Test your knowledge on these vital biological compounds essential for human health.

More Like This

Use Quizgecko on...
Browser
Open
Browser
Browser