Unsaturated fatty acids have...
double bonds in the carbon chain where there are less than two hydrogens per carbon atom
Difference between fats and oils?
Fats contain saturated fatty acids and are solid at room temperature, while oils contain unsaturated fatty acids and are liquid at room temperature.
What do animals use for long-term energy storage?
Fat rather than glycogen because fat stores more energy
How are phospholipids constructed?
They are constructed like neutral fats except that the third fatty acid is replaced by a polar (hydrophilic) phosphate group; the phosphate group usually bonds to another organic group (R)
What do the hydrocarbon chains of the fatty acids become?
They become the nonpolar (hydrophobic) tails.
How do phospholipids arrange themselves? And what does this allow phospholipids to create?
They arrange themselves in a double layer in water, so the polar heads face toward water molecules and nonpolar tails face toward one another, away from water molecules. ---- This allows phospholipids to create a separation between two solutions (the interior and exterior of a cell, for example); the plasma membrane is a phospholipid bilayer.
What are steroids made up of and what do those functional groups enable steroids to do?
Steroids have skeletons of four fused carbon rings and vary according to attached functional groups; these functional groups determine the biological functions of the various steroid molecules.
What does cholesterol do in general or generally act as?
It is a component of an animal cell's plasma membrane and is the precursor of the steroid hormone (aldosterone, testosterone, estrogen, calcitriol, etc.)
What do waxes do in general and in plants and animals?
They have a high melting point, are waterproof, and resist degradation. In plants, they form a protective covering in plants that retards water loss in leaves and fruits. In animals, waxes maintain animal skin and fur, trap dust and dirt, and form the honeycomb.