Elements of Human Nutrition - Lipids

Flashcards testing vocabulary and key concepts from the BCHM2300 lecture on Lipids, including triglycerides, fatty acid structures, phospholipids, sterols, and dietary recommendations.

Triglyceride

The primary dietary and storage lipid composed of a glycerol backbone bound to three fatty acid chains through esterification.

Saturated Fatty Acid

A fatty acid chain with no carbon-carbon double bonds, containing the maximum possible number of hydrogen atoms.

Monounsaturated Fatty Acid

A fatty acid chain that contains exactly one carbon-carbon double bond.

Polyunsaturated Fatty Acid

A fatty acid chain that contains two or more carbon-carbon double bonds.

Lauric Acid

A $12$-carbon saturated fatty acid ($C12:0$) predominantly found in coconut oil.

Myristic Acid

A $14$-carbon saturated fatty acid ($C14:0$) commonly found in nutmeg.

Palmitic Acid

A $16$-carbon saturated fatty acid ($C16:0$) found in palm oil.

Stearic Acid

An $18$-carbon saturated fatty acid ($C18:0$) commonly found in animal fats.

Arachidic Acid

A $20$-carbon saturated fatty acid ($C20:0$) found in vegetable and fish oils.

Palmitoleic Acid

A $16$-carbon monounsaturated fatty acid ($C16:1$) found in butter.

Oleic Acid

An $18$-carbon monounsaturated fatty acid ($C18:1$) commonly found in olives and corn.

Cis Double Bond

An unsaturated fatty acid configuration where hydrogen atoms around a double bond are on the same side, causing a kink or bend in the carbon chain.

Trans Double Bond

An unsaturated fatty acid configuration where hydrogen atoms around a double bond are on opposite sides, allowing the carbon chain to remain straight.

Omega Carbon

The carbon atom located at the methyl ($CH_3$) end of a fatty acid chain, designated as carbon 1 in omega notation.

Esterification

The chemical bonding process between the hydroxyl groups of glycerol and the carboxyl groups of fatty acids that releases water and forms triglycerides.

Phospholipid

An amphipathic lipid structure composed of a glycerol backbone attached to two fatty acids, a phosphate group, and a choline group.

Lecithin

A non-essential phospholipid (phosphatidylcholine) found in egg yolks, soybeans, wheat germ, and peanuts, synthesized in adequate amounts by the liver.

Gonane

The core four-ring fused steroid nucleus (cyclopentanoperhydrophenanthrene) present in sterols and steroid hormones.

Cholesterol

The most prevalent sterol ($C_{27}$) in animal products, synthesized in the liver and used as a precursor for bile salts, Vitamin D, and steroid hormones.

Adipokines

Hormones secreted by adipose tissue, such as leptin, adiponectin, resistin, and visfatin, involved in metabolic regulation.

Linoleic Acid

An essential omega-6 polyunsaturated fatty acid ($18:2\,n-6$) required by the human body to synthesize arachidonic acid.

Alpha-Linolenic Acid (ALA)

An essential omega-3 polyunsaturated fatty acid ($18:3\,n-3$) required by the body to synthesize eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).

Eicosanoids

Biologically active, hormone-like signaling molecules derived from arachidonic acid (pro-inflammatory) and EPA (anti-inflammatory).

Desaturase Enzymes

Enzymes that introduce double bonds into fatty acid chains; humans lack $\Delta^{12}$ and $\Delta^{15}$ desaturases, making linoleic and alpha-linolenic acids dietary essentials.

Essential Fatty Acid Deficiency (EFAD)

A rare deficiency state causing symptoms like joint pain, memory impairment, low energy, cold hands, and reduced vision, linked to conditions like IBS, CF, or SI resectioning.

Blood Lipid Profile Target Levels

Clinical reference values for cardiovascular health: Total cholesterol < $200\,mg/dL$, LDL < $100\,mg/dL$, HDL > $60\,mg/dL$, and Triglycerides < $150\,mg/dL$.

Acceptable Macronutrient Distribution Range (AMDR) for Fat

Recommended daily fat intake guideline specifying that $20 - 35\%$ of total daily calories should come from fat, limiting saturated and trans fats to under $10\%$.

Olestra

An unabsorbable, zero-calorie artificial fat substitute consisting of a sucrose molecule esterified with up to 8 fatty acid chains.