Chapter 1-8 Lipids and Emulsions (Video Notes)

Flashcards cover fatty acid types, triglycerides, saponification, soap chemistry, emulsification, hydrogenation, trans fats, and related concepts from the lecture notes.

What are the two main categories of fatty acids discussed in the notes?

Saturated fats and unsaturated fats.

What is the typical carbon chain length and branching pattern for most fatty acids?

Even-numbered chains, usually 10–20 carbons long, and not branched (straight chains).

What does 'essential fatty acid' mean?

A fatty acid not synthesized by the body and must be obtained from the diet; some essential fatty acids are unsaturated, and there may be essential saturated fats though this is less clear.

Which type of fat is typically derived from animals and is solid at room temperature?

Saturated fats.

Which type of fat is typically derived from plants and is liquid at room temperature?

Unsaturated fats.

What is the difference between cis and trans double bonds in unsaturated fats?

Cis: hydrogens on the same side of the double bond; Trans: hydrogens on opposite sides.

What is saponification?

Base-catalyzed ester hydrolysis of triglycerides to produce glycerol and fatty acid salts (soap).

What are the products of saponification of a triglyceride with a base?

Glycerol (glycerin) and the fatty acid salts (soap).

What is a triglyceride (triglycerol)?

A molecule with three fatty acids attached to a glycerol backbone.

Why do soaps emulsify oils in water?

Soap molecules have a hydrophobic tail and a hydrophilic head; they form micelles that trap oil and allow it to be washed away in water.

What are the hydrophilic and hydrophobic parts of a soap molecule?

The hydrophilic head likes water; the hydrophobic tail does not and avoids water.

What causes soap scum in hard water?

Calcium and magnesium ions form insoluble precipitates with soap, reducing lather.

What is hydrogenation, and what is its effect on fats?

Addition of hydrogen to unsaturated fats to make them more saturated; increases solidification; partial hydrogenation can produce trans fats.

What are trans fats and how are they formed?

Trans fats have trans double bonds (hydrogens on opposite sides); formed by partial hydrogenation; generally unhealthy and often regulated.

What is lecithin and its role as an emulsifier?

Lecithin is phosphatidylcholine; acts as an emulsifier to help oil mix with water in foods (e.g., pancake batter, peanut butter cups).

How does the melting point relate to saturated vs unsaturated fats?

Saturated fats are solid at room temperature; unsaturated fats are liquids; double bonds reduce packing efficiency and lower the melting point.

What is the relationship between triglycerides and glycerol?

Three fatty acids attach to glycerol to form a triglyceride.