Lipids (Fats) Lecture Notes

This set covers the chemistry, functions, and classifications of lipids (fats) as presented in the lecture.

Energy provided by Fat

$$9\,kcal/g$$

Adipose tissue

Tissue containing fat-storing cells where fat storage is unlimited.

Fat cell hormone secretion

Cells that secrete hormones to help regulate appetite.

Energy during rest

Fat stored in fat cells supplies $60\%$ of the energy needs during this state.

Ketone bodies

A special form of fat from which brain and nerve cells can derive about half of their energy during food deprivation or starvation.

Monoglycerides

Molecules of glycerol with one fatty acid attached; the single units of lipids used by the body for absorption.

Triglycerides

Molecules consisting of three fatty acids attached to a glycerol.

Fatty acid chain length

One of two ways fatty acids differ, determined by the number of carbons.

Saturated Fatty Acid

A fatty acid where every available carbon is filled to capacity with hydrogen atoms.

Unsaturated Fatty Acid

A fatty acid where hydrogen atoms are missing or there are carbons not holding hydrogen atoms.

Monounsaturated Fat

A fatty acid with only one point of unsaturation.

Polyunsaturated Fat

A fatty acid with two or more points of unsaturation.

Lard

The most saturated and hardest fat.

Oil

The most unsaturated fat, which is liquid at room temperature.

Rancidity

A condition that occurs when fats are exposed to oxygen; polyunsaturated fatty acids spoil faster due to unstable double bonds.

Hydrogenation

The process of adding hydrogen atoms to some or all points of unsaturation to protect against oxidation, prolong shelf life, and alter texture.

Cis-fatty acids

A type of unsaturated fatty acid with a bent or kinked form.

Trans-fatty acids

A type of unsaturated fatty acid with a straight or linear form that behaves like saturated fat by increasing blood cholesterol and heart disease risk.