Lipids Flashcards
What are triglycerides?
The major form of lipids in food and in the body, composed of three fatty acids attached to a glyceride backbone
Define hydrophobic.
Insoluble in water
What does lipophilic mean?
Attracted to fat and fat solvents; fat-soluble
What is hydrophilic?
Can mix with or dissolve in water
Define lipophobic.
Adverse to fat solvents; insoluble in fat and fat solvents
What are phospholipids?
Compounds consisting of a glycerol molecule bonded to two fatty acids and a phosphate group
What are sterols?
A category of lipids that includes cholesterol, characterized by multiple ring structures
What are fatty acids?
Compounds containing a long hydrocarbon chain with a carboxyl group (–COOH) at one end
What does chain length refer to in fatty acids?
The number of carbons that a fatty acid contains
Define saturated fatty acid.
A fatty acid completely filled by hydrogen with all carbons linked by single bonds
What is an unsaturated fatty acid?
A fatty acid in which the carbon chain contains one or more double bonds
What is a monounsaturated fatty acid (MUFA)?
A fatty acid in which the carbon chain contains one double bond
Define polyunsaturated fatty acid (PUFA).
A fatty acid in which the carbon chain contains two or more double bonds
What is a cis fatty acid?
Unsaturated fatty acid with hydrogens on the same side of the double bond, causing a bend in the chain
Define trans fatty acids.
Unsaturated fatty acids with hydrogens on opposite sides of the double bond, straightening the chain
What is hydrogenation?
A chemical reaction in which hydrogen atoms are added to carbon–carbon double bonds
What is conjugated linoleic acid (CLA)?
A polyunsaturated fatty acid with alternating single and double bonds
What is elongation in the context of fatty acids?
Addition of carbon atoms to fatty acids to lengthen them
What does desaturation mean?
Insertion of double bonds into fatty acids
Define omega-9 fatty acid.
Any polyunsaturated fatty acid with the first double bond between the ninth and tenth carbon atoms
What are omega-3 fatty acids?
Polyunsaturated fatty acids with the first double bond between the third and fourth carbon atoms
What defines omega-6 fatty acids?
Polyunsaturated fatty acids with the first double bond between the sixth and seventh carbon atoms
What are nonessential fatty acids?
Fatty acids that the body can synthesize and do not need to be consumed
What are eicosanoids?
A class of hormone-like substances formed from long-chain fatty acids
What is linoleic acid?
An essential omega-6 fatty acid with 18 carbon atoms and 2 double bonds
Define alpha-linolenic acid.
An essential omega-3 fatty acid with 18 carbon atoms and 3 double bonds
What is glycerol?
An alcohol with three carbon atoms, forming the backbone of triglycerides
What is an ester?
A chemical combination of an organic acid and an alcohol
Define esterification.
A condensation reaction creating an ester from an organic acid and an alcohol
What are diglycerides?
Molecules composed of glycerol combined with two fatty acids
What are monoglycerides?
Molecules composed of glycerol combined with one fatty acid
What are adipocytes?
Fat cells
What is adipose tissue?
Body fat tissue
Define visceral fat.
Fat stores that cushion body organs
What is subcutaneous fat?
Fat stores located under the skin
What is lanugo?
Soft, downy hair that covers a normal fetus and appears on semi-starved individuals
What happens during oxidation of unsaturated fatty acids?
Oxygen attaches to the double bonds, leading to rancidity
What is a phosphate group?
A chemical group (–PO4) with phosphorus bonded to four oxygens
What is choline?
A nitrogen-containing compound part of phosphatidylcholine and acetylcholine
What is lecithin?
A phospholipid in the body that contains choline
What are micelles?
Tiny emulsified fat packets that can enter enterocytes
Define lipoprotein.
Complexes that transport lipids in the lymph and blood
What is a chylomicron?
A large lipoprotein particle formed in intestinal cells after fat absorption
What are very-low-density lipoproteins (VLDLs)?
Triglyceride-rich lipoproteins formed in the liver
What are intermediate-density lipoproteins (IDLs)?
Lipoproteins formed when triglycerides are stripped from VLDL
Define low-density lipoproteins (LDLs).
Cholesterol-rich lipoproteins from the breakdown of IDL
What are high-density lipoproteins (HDLs)?
Blood lipoproteins with high levels of protein and low levels of triglycerides
