Which of the following statements about lipids and fatty acids is correct?
Saturated fatty acids contain carbon-carbon double bonds which introduce kinks into the hydrocarbon chain.
Lipids containing a high proportion of saturated fatty acids are typically solid at room temperature because their straight chains pack closely together.
Unsaturated fatty acids pack more tightly than saturated fatty acids, leading to higher melting points.
Phospholipids are completely hydrophobic molecules that lack any polar or charged regions.