Chapter 5: Lipids

Vocabulary-style flashcards covering the types, structures, digestion, and health effects of lipids based on lecture notes.

Triglycerides

The predominate form of fat in foods and the major storage form of fat in the body, composed of $3$ fatty acids and glycerol.

Fatty Acids

Organic acids consisting of a carbon chain with hydrogens attached, featuring an acid group at one end and a methyl group at the other end.

Saturated fatty acid

A fatty acid with carbon chains filled with hydrogen atoms and no $C=C$ double bonds; these are typically solid at room temperature.

Monounsaturated fat

A triglyceride containing fatty acids with $1$ double bond, found in oils such as canola and olive oil.

Polyunsaturated fat

Triglycerides containing a high percentage of fatty acids with $>2$ double bonds; they appear liquid at room temperature and include corn, safflower, and fish oils.

Omega number

Refers to the position of the double bond nearest the methyl ($CH_3$) end of the carbon chain in a fatty acid.

Hydrogenation

The process of adding hydrogen to unsaturated fat to make it more "solid" or firm, which increases shelf stability and protects against oxidation.

Cis-fatty acid

A naturally occurring configuration where hydrogens next to double bonds are on the same side, causing the molecule to fold back into a U-like formation.

Trans-fatty acid

A configuration where hydrogens are on opposite sides of the double bond, making the molecule more linear; typically occurs in partially hydrogenated foods.

Phospholipids

Lipids with a structure similar to triglycerides but with only $2$ fatty acids and a choline group; they act as emulsifiers and are part of cell membranes.

Lecithin

A specific phospholipid found in foods such as egg yolks, soybeans, wheat germ, and peanuts.

Sterols

Compounds with a carbon ring structure, including cholesterol, Vitamin $D_3$, bile, and sex hormones like testosterone.

Lipoproteins

Clusters of lipids and proteins used as transport vehicles for fat through watery blood fluids.

Chylomincrons

The largest and lowest density lipoproteins, which contain the highest amount of triglycerides.

LDL (Low-density lipoproteins)

Lipoproteins that are about half cholesterol and are implicated in heart disease.

HDL (High-density lipoproteins)

Lipoproteins that are about half protein, giving them a high density.

Essential fatty acids

Two polyunsaturated fatty acids that must be provided in the diet: Linoleic (omega-$6$) and Linolenic (omega-$3$).

Bile

A substance made by the liver and stored in the gallbladder that acts as an emulsifier to aid fat digestion in the small intestine.

Olestra

A fat-based substitute made from sucrose and fatty acids that passes through the body undigested.

Pancreatic lipase

An enzyme that flows from the pancreas into the small intestine to hydrolyze emulsified fats into monoglycerides, glycerol, and fatty acids.