Structure and Classification of Lipids Flashcards

Questions and Answers

What is a lipid?

Organic compound soluble in water

Compound that contains carbohydrates

Compound that only exists in animals

Organic compound found in living organisms that is insoluble in water (correct)

What do lipids lack in terms of structural features?

Do not have a common structural feature

What are the classifications of lipids based on biochemical function?

Biochemical function and saponification

What are energy-storage lipids?

Triacylglycerols Signup and view all the answers

Which of the following are considered membrane lipids?

Cholesterol Signup and view all the answers

What are emulsification lipids?

Bile acids Signup and view all the answers

What comprises messenger lipids?

Steroid hormones and eicosanoids Signup and view all the answers

What are protective coating lipids?

Biological waxes Signup and view all the answers

What is the saponification reaction?

Hydrolysis reaction that occurs in a basic solution Signup and view all the answers

What are saponifiable lipids?

Converted into two or more smaller molecules when hydrolysis occurs Signup and view all the answers

Which of the following are examples of nonsaponifiable lipids?

Steroid hormones Signup and view all the answers

What defines fatty acids?

Naturally occurring monocarboxylic acids with linear carbon chains and an even number of carbon atoms Signup and view all the answers

What defines long chain fatty acids?

C12-C26 Signup and view all the answers

What defines medium chain fatty acids?

C8-C10 Signup and view all the answers

What defines short chain fatty acids?

C4-C6 Signup and view all the answers

What are the types of fatty acids?

Saturated and unsaturated Signup and view all the answers

What is a saturated fatty acid?

Fatty acid that has each carbon atom within the chain filled with hydrogen atoms, all bonds are single bonds Signup and view all the answers

What characterizes a monounsaturated fatty acid?

Contains one carbon-carbon double bond in its backbone and is nearly always in a cis configuration Signup and view all the answers

What is a polyunsaturated fatty acid?

Fatty acid with two or more double bonds Signup and view all the answers

What are the two types of unsaturated fatty acids?

Omega-3 fatty acid and omega-6 fatty acid Signup and view all the answers

What is the melting point of fatty acids affected by?

Lower melting point, the more unsaturated the lower the melting point, liquid at room temperature Signup and view all the answers

What is the water solubility of short-chain fatty acids?

Have some solubility Signup and view all the answers

What is the water solubility of long-chain fatty acids?

Insoluble in water Signup and view all the answers

Why are short-chain fatty acids only sparingly soluble?

Because of the presence of the carboxylic group Signup and view all the answers

Study Notes

Lipids Overview

Lipids are organic compounds in living organisms that are insoluble in water and soluble in non-polar organic solvents.
They lack a common structural feature, creating a diverse group of molecules.

Classification of Lipids

Classified based on biochemical function and saponification.
Includes energy-storage lipids, membrane lipids, emulsification lipids, messenger lipids, and protective coating lipids.

Types of Lipids

Energy-storage lipids: Primarily triacylglycerols, used for storing energy.
Membrane lipids: Composed of phospholipids, glycolipids, and cholesterol, these form biological membranes.
Emulsification lipids: Example includes bile acids, which aid in fat digestion.
Messenger lipids: Include steroid hormones and eicosanoids, crucial for signaling.
Protective coating lipids: Biological waxes that provide waterproofing and protection.

Saponification

A chemical process involving hydrolysis in a basic solution.
Results in saponifiable lipids, which can be broken down into smaller molecules during hydrolysis.
Examples include triacylglycerols, phospholipids, sphingoglycolipids, cholesterol, and biological waxes.
Nonsaponifiable lipids include steroid hormones, bile acids, and eicosanoids, which do not undergo this process.

Fatty Acids

Naturally occurring monocarboxylic acids with linear carbon chains, typically having an even number of carbon atoms.
Classified by chain length:
- Long-chain fatty acids (C12-C26)
- Medium-chain fatty acids (C8-C10)
- Short-chain fatty acids (C4-C6).

Types of Fatty Acids

Two main types: saturated and unsaturated fatty acids.
Saturated Fatty Acid (SFA): Fully hydrogenated with no double bonds; structural notation starts from the carboxyl end.
Monounsaturated Fatty Acid (MUFA): Contains one cis carbon-carbon double bond.
Polyunsaturated Fatty Acid (PUFA): Contains two or more double bonds, important for health.

Unsaturated Fatty Acids

Numbering of double bonds starts from the opposite end of the carboxyl group.
Structural notation indicates the total number of carbons and double bonds.
Types include omega-3 and omega-6 fatty acids, which are essential for health.

Physical Properties of Fatty Acids

Water solubility varies by chain length:
- Short-chain fatty acids are partially soluble due to the carboxylic group.
- Long-chain fatty acids are insoluble in water.
Melting points are influenced by saturation:
- More unsaturated fatty acids have lower melting points and are typically liquid at room temperature.

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Description

Discover the essential concepts of lipids and fatty acids through these flashcards. From definitions to classifications, this resource provides a clear understanding of lipid structures and their biochemical functions. Perfect for students studying biochemistry or related disciplines.