Which combination correctly contrasts cis and trans double-bond configurations in unsaturated fatty acids with respect to hydrogen placement, shape, and enzymatic handling by human metabolism?

Which statement best explains why linoleic acid (LA) is considered essential in the human diet?

You are shown a verbal description of a skeletal fatty-acid fragment: 'a zigzag with five vertices and a terminal carboxyl drawn at the rightmost end.' Explain how many carbons are present in the hydrocarbon chain portion (excluding the carboxyl carbon) and how many implicit hydrogens would a fully saturated version have attached to those internal carbons (total H on the chain carbons only, ignoring COOH H/O).

A clinical nutritionist wants to design a formula for rapid energy delivery to a patient. Which fatty acid type should they incorporate to maximize rapid absorption and oxidation, and why?

A food-processing lab converts some cis unsaturated fats to trans isomers via partial hydrogenation. Which chain-level mechanistic consequences best explain why partially hydrogenated oils increase cardiovascular risk compared to the original cis-rich oil?

A vegan student eats lots of ALA-rich foods (flaxseed, chia) but no fish. Which of the following is the most accurate guidance based on conversion efficiency of ALA to EPA/DHA?

Which dietary source would best supply preformed EPA and DHA to bypass inefficient conversion from ALA?

In a skeletal formula of a fatty acid, what do the unlabeled sharp corners (vertices) along the zigzag chain represent?

If the first double bond in a fatty acid is located three carbons away from the terminal methyl (omega) carbon, which omega designation applies and which common dietary fatty acid fits that category?

Which of these statements correctly indicates a metabolic limitation humans have regarding double-bond configurations?