Chpt 17

Lipids

Biomolecules that are soluble in organic solvents but not in water. They serve multiple purposes in the body, such as storing energy, protecting and insulating internal organs, and acting as chemical messengers.

Cholesterol

A type of lipid that can accumulate in the arteries and lead to the formation of deposits on the arterial walls. High levels of cholesterol can increase the risk of heart attack and stroke.

Familial Hypercholesterolemia (FH)

A genetic mutation that blocks the removal of cholesterol from the blood, resulting in high cholesterol levels and increased risk of cardiovascular disease.

Clinical Lipid Specialist

A healthcare professional who specializes in the diagnosis and treatment of lipid disorders such as high cholesterol, high triglycerides, and obesity. They assess lipid profiles, provide dietary recommendations, and prescribe lipid-lowering medications.

Total Cholesterol

The measurement of all types of cholesterol in the blood, including LDL (low-density lipoprotein) cholesterol and HDL (high-density lipoprotein) cholesterol. A desirable level is less than 200 mg/dl.

Lipid Profile

A blood test that measures the levels of different types of lipids, including total cholesterol, LDL cholesterol, and HDL cholesterol.

Triacylglycerols

A type of lipid that contains the alcohol glycerol and three fatty acids. They are a major form of stored energy in the body.

Glycerophospholipids

A type of lipid that contains the alcohol glycerol, two fatty acids, and a phosphate group. They are important components of cellular membranes.

Sphingolipids

A type of lipid that contains the amino alcohol sphingosine. They have various functions in the body, including cell signaling and structural support.

Steroids

A type of lipid that has a different structure from other lipids. They are characterized by a steroid nucleus of four fused carbon rings and have various functions in the body, including hormone production and cell membrane stability.

Palmitic acid

A saturated fatty acid with a carbon chain length of 16.

Unsaturated fatty acids

Fatty acids that contain one or more double bonds in their carbon chain.

Melting point

The temperature at which a solid substance changes into a liquid state.

Saturated fatty acids

Fatty acids that do not contain any double bonds in their carbon chain.

Dispersion forces

Weak forces of attraction between molecules.

Regular pattern

A consistent arrangement or sequence.

Interactions

The ways in which molecules or particles affect each other.

Cis double bond

A type of double bond in which the hydrogen atoms are on the same side of the carbon chain.

Stacking

The arrangement of molecules in a closely packed manner.

Solids

Substances that have a definite shape and volume at room temperature.

Liquids

Substances that have a definite volume but take the shape of their container at room temperature.

Condensed structural formula

A way of representing the structure of a molecule using lines to represent bonds and omitting certain atoms or groups.

Carboxylic acid group

A functional group consisting of a carbon atom double bonded to an oxygen atom and single bonded to a hydroxyl group.

Monounsaturated fatty acid

A fatty acid with one double bond in its carbon chain.

Polyunsaturated fatty acid

A fatty acid with two or more double bonds in its carbon chain.

Insoluble

Not able to dissolve in a particular solvent, such as water.

Omega-6 fatty acids

Fatty acids in which the first double bond occurs at carbon 6 counting from the methyl end of the carbon chain.

Omega-3 fatty acids

Fatty acids in which the first double bond occurs at the third carbon counting from the methyl group.

Plaques

Deposits of cholesterol and other substances that adhere to the walls of blood vessels.

Prostaglandins

Hormone-like substances produced in small amounts in most cells of the body.

Prostaglandin E (PGE)

A type of prostaglandin that has a ketone group on carbon 9.

Prostaglandin F (PGF)

A type of prostaglandin that has a hydroxyl group.

Arachidonic acid

An acid that is converted to prostaglandins when tissues are injured, causing inflammation and pain.

Nonsteroidal anti-inflammatory drugs (NSAIDs)

Drugs that block the production of prostaglandins, decreasing pain, inflammation, and fever.

Ibuprofen

An NSAID that has anti-inflammatory and pain relief effects.

NSAIDs

Abbreviation for nonsteroidal anti-inflammatory drugs.

Glaucoma

A group of diseases that cause an increase in fluid pressure in the eye, leading to damage to the optic nerve.

Bimatoprost

A prostaglandin analog used in the treatment of glaucoma to increase fluid drainage.

Latisse

The brand name for bimatoprost when used for cosmetic purposes to lengthen eyelashes.

Waxes

Esters of long-chain fatty acids and long-chain alcohols, found in plants and animals, providing waterproof coating and preventing water loss.

Beeswax

A type of wax obtained from honeycomb, used for making candles, shoe polish, and wax paper.

Carnauba wax

A type of wax obtained from palm trees, used for waxes in furniture, cars, floors, and shoes.

Jojoba wax

A type of wax obtained from the jojoba bush, used in making candles, soaps, and cosmetics.

Lanolin

A mixture of waxes obtained from wool, used in hand and facial lotions to retain water and soften the skin.

Triacylglycerols

Fatty acids stored in the body as triacylglycerols, also known as triglycerides, which are esters of glycerol and fatty acids.

Glycerol

A trihydroxy alcohol that forms ester bonds with fatty acids to create triacylglycerols.

Fatty acids

Organic acids that form ester bonds with glycerol in triacylglycerols.

Ester bond

A chemical bond formed between the hydroxyl group of glycerol and the carboxyl group of a fatty acid in a triacylglycerol.

Triacylglycerol

A major form of energy storage for animals, especially during hibernation.

Fat

A solid triacylglycerol at room temperature, usually derived from animal sources.

Oil

A liquid triacylglycerol at room temperature, usually derived from plant sources.

Melting point

The temperature at which a solid fat or wax changes into a liquid state.

Monounsaturated

A type of oil that contains a high amount of oleic acid, with one double bond.

Polyunsaturated

A type of oil that contains a high amount of fatty acids with two or more double bonds.

Saturated fatty acids

Fatty acids that have no double bonds between carbon atoms and are solid at room temperature.

Unsaturated fatty acids

Fatty acids that have one or more double bonds between carbon atoms and are liquid at room temperature.

Melting point

The temperature at which a solid substance changes into a liquid state.

Animal fats

Fats derived from animal sources, usually containing higher amounts of saturated fatty acids.

Vegetable oils

Oils derived from plant sources, usually containing higher amounts of unsaturated fatty acids.

Lauric acid

A saturated fatty acid with 12 carbon atoms, commonly found in coconut oil.

Stearic acid

A saturated fatty acid with 18 carbon atoms, commonly found in animal fats.

Triacylglycerol

A type of lipid molecule composed of three fatty acids bonded to a glycerol molecule.

Hydrogenation

A chemical reaction in which hydrogen gas is added to unsaturated fatty acids, converting them into saturated fatty acids.

Hydrolysis

A chemical reaction in which an ester bond is broken by the addition of water, resulting in the separation of glycerol and fatty acids.

Saponification

A chemical reaction in which an ester bond is broken by the addition of a strong base, resulting in the formation of glycerol and soap molecules.

Lipase

An enzyme that catalyzes the hydrolysis of lipids.

Hydrolysis

The chemical reaction in which a compound is broken down by the addition of water.

Triacylglycerols

A type of lipid composed of three fatty acids bonded to a glycerol molecule.

Ester bonds

The bonds between the glycerol molecule and the fatty acids in a triacylglycerol.

Glycerol

A polar molecule that is a byproduct of the hydrolysis of triacylglycerols.

Fatty acids

Organic molecules with a long hydrocarbon chain that are a byproduct of the hydrolysis of triacylglycerols.

Saponification

The reaction in which a fat or oil is heated with a strong base to form glycerol and the salts of fatty acids, commonly known as soap.

Sodium hydroxide (NaOH)

A strong base commonly used in saponification reactions to produce solid soap.

Potassium hydroxide (KOH)

A strong base commonly used in saponification reactions to produce liquid soap.

Polyunsaturated

Referring to a fat or oil that contains multiple double bonds in its fatty acid chains.

Soap

The salts of fatty acids produced during saponification reactions.

Hydrogenation

The chemical reaction in which unsaturated fats are converted into saturated fats by adding hydrogen.

Reactants

The substances that undergo a chemical reaction.

Products

The substances that are formed as a result of a chemical reaction.

Lipids

A class of organic compounds that are insoluble in water but soluble in organic solvents, including fats, oils, waxes, phospholipids, and steroids.

Phospholipids

A type of lipid that is a major component of cell membranes, consisting of a glycerol molecule, two fatty acid chains, a phosphate group, and a polar head group.

Glycerophospholipids

A subclass of phospholipids that contain glycerol as the backbone and have two fatty acid chains attached to the glycerol molecule.

Sphingomyelins

A type of phospholipid that contains sphingosine instead of glycerol as the backbone.

Amino alcohols

Organic compounds that contain both an amino group and a hydroxyl group.

Choline

An amino alcohol found in glycerophospholipids, lecithins, and cephalins.

Serine

An amino alcohol found in glycerophospholipids, lecithins, and cephalins.

Ethanolamine

An amino alcohol found in glycerophospholipids, lecithins, and cephalins.

Lecithins

A type of glycerophospholipid that contains choline as the polar head group.

Cephalins

A type of glycerophospholipid that usually contains ethanolamine as the polar head group and sometimes serine.

Polar head

The ionized amino alcohol and phosphate portion of a glycerophospholipid that is attracted to water.

Nonpolar tails

The hydrocarbon chains of the two fatty acids in a glycerophospholipid that are soluble in nonpolar substances.

Phosphoric acid

A compound that forms an ester bond with the hydroxyl group of glycerol in a glycerophospholipid.

Condensed structural formula

A way of representing the structure of a molecule that shows the connectivity of atoms and omits certain details.

Sphingosine

A long-chain amino alcohol found in sphingomyelins and other sphingolipids.

Amide bond

A type of chemical bond that forms between the amine group of sphingosine and a fatty acid in a sphingomyelin.

Myristic acid

A fatty acid commonly found in sphingomyelins and other lipids.

White matter

The region of the central nervous system that contains myelinated nerve fibers.

Myelin sheath

A protective covering around nerve cells that increases the speed of nerve impulses and insulates and protects the nerve cells.

Multiple sclerosis

A disease in which sphingomyelin is lost from the myelin sheath, leading to deterioration of the sheath and impaired transmission of nerve signals.

Sphingomyelin

A type of phospholipid found in the myelin sheath that surrounds nerve cells.