BIOCHEM LEC_Module 5

Lipids

Lipids

Organic compounds found in living organisms that are classified together based on common solubility properties.

Triglycerides

Lipids that are triesters formed from 3 fatty acids esterified to the 3 hydroxyl groups of glycerol.

Fatty acids

Naturally occurring monocarboxylic acids that are structural components of all lipids and building blocks of lipids.

Simple lipids

Lipids that include triglycerides (fats and oils) and waxes.

Complex lipids

Lipids that include phospholipids and sphingoglycolipids.

Steroids

Lipids that include cholesterol and steroid hormones.

Prostaglandins

Lipids that serve as chemical messengers and include prostaglandins, thromboxanes, and leukotrienes.

Insulation

The role of lipids in reducing or slowing heat loss or gain by providing a barrier between areas with significant temperature changes.

Protection

The role of lipids in providing mechanical shock protection, including biological waxes, skin, and hair.

Prevention

The role of lipids in preventing loss of heat energy.

Solubility

Lipids are classified based on their solubility, being insoluble in water but soluble in nonpolar organic solvents.

Energy storage

Lipids store energy within fat cells in the form of triglycerides.

Membrane lipids

Lipids such as phospholipids, sphingoglycolipids, and cholesterol that are important for the formation of cell membranes.

Messenger lipids

Lipids such as steroid hormones, prostaglandins, thromboxanes, and leukotrienes that serve as chemical messengers in the body.

Protective coating lipids

Biological waxes that provide a protective coating on surfaces.

Emulsification lipids

Bile acids that aid in the emulsification of fats during digestion.

Esters

Functional groups found in lipids, consisting of an acid part and an alcohol part.

Long-chain fatty acids

Fatty acids with carbon chain lengths ranging from C12 to C26.

Medium-chain fatty acids

Fatty acids with carbon chain lengths ranging from C6 to C11.

Short-chain fatty acids

Fatty acids with carbon chain lengths ranging from C4 to C5.

Saturated fatty acids

Fatty acids with all carbon-carbon bonds being single bonds, solid to semi-solid at room temperature.

Unsaturated fatty acids

Fatty acids with one or more carbon-carbon double bonds, liquid at room temperature.

Unsaturated (Oils)

Lipids that have a presence of double bond/s and are liquid at room temperature. They are sourced from plants.

Mono-Unsaturated (MUFA)

A type of unsaturated fatty acid that has only one double bond (C=C). It has a carbon chain with one carbon-carbon double bond, and the configuration about the double bond is nearly always cis.

Poly-Unsaturated (PUFA)

A type of unsaturated fatty acid that has two or more double bonds (C=C=C). It has a carbon chain with two or more carbon-carbon double bonds, and up to six double bonds can be found in biochemically important PUFAs.

Omega (ω) 3 Fatty Acid

An unsaturated fatty acid with its endmost double bond 3 carbon atoms away from its methyl end. It is sourced from fish that live in deep cold water and has a positive effect on heart health.

Omega (ω) 6 Fatty Acid

An unsaturated fatty acid with its endmost double bond 6 carbon atoms away from its methyl end. It is sourced from plant oils.

Essential Fatty Acids

Some unsaturated fatty acids, such as Omega-3 and Omega-6, ALA, DHA, and EPA, that the body cannot synthesize and must be consumed as part of the diet.

Linoleic Acid

An essential Omega-6 fatty acid that is needed for proper membrane structure and serves as a starting material for the production of nutritionally important longer-chain omega-6 fatty acids.

Fats

Lipids that come from animals and are generally solids at room temperature. They are mixtures of triglycerides containing a high proportion of long-chain, saturated fatty acids.

Oils

Liquid fats that come from plants or fish. They are mixtures of triglycerides containing a high proportion of long-chain, unsaturated fatty acids or short-chain, saturated fatty acids.

Good Fats

Monounsaturated fats and Omega-3 and Omega-6 fatty acids that are considered beneficial for a balanced diet.

Bad Fats

Saturated fats and trans-monounsaturated fats that are considered detrimental to health when consumed in excess.

Melting Point

The temperature at which a solid fat or fatty acid changes into a liquid state. It is influenced by the length of the carbon chain and the degree of saturation.

Saturated Fatty Acids

Fatty acids that have no double bonds and higher melting points compared to unsaturated fatty acids.

Unsaturated Fatty Acids

Fatty acids that have one or mor e double bonds and lower melting points compared to saturated fatty acids.

Fatty Acid Nomenclature

The naming system for fatty acids that includes the number of carbon atoms, the number and position of double bonds, and the position of the first double bond from the methyl end.