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How do cis and trans fatty acids differ in molecular shape?

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Synthesis of palmitate — Fat Palmitic acid is one of the most prevalent fatty acids occurring in the oils and fats of animals; it also occurs naturally in palm oil. It is generated through the addition of an acetyl group to multiple malonyl groups connected by single bonds between carbons. This structure forms a saturated acid—a major component of solid glycerides.

The difference between cis and trans fatty acids lies in the spatial arrangement of the hydrocarbon chains around their carbon-carbon double bonds.

Cis configuration: In this form, the two hydrogen atoms (or hydrocarbon chains) attached to the double-bonded carbons lie on the same side of the molecule. This creates a "v" shape or a bend at the point of the double bond, which prevents the molecules from packing tightly together, typically resulting in a liquid state at room temperature.12
Trans configuration: In this form, the hydrocarbon chains lie on opposite sides of the double-bonded carbons. This arrangement results in a more linear, straighter molecular structure that resembles the shape of a saturated fat. Because of this linear shape, trans fats can pack more closely together, which often gives them a more solid or semisolid consistency.2

While cis configurations are the standard form found in biological unsaturated fatty acids, the trans configuration is primarily produced through industrial hydrogenation or by certain microorganisms in ruminant animals.12