What are the two kinds of subunits that make up a fat molecule and how are they arranged in the molecule?

Question

how do phospholipids and steroids differ from triglycerides?

Answer 1

Triglyceride (aka triglycerol aka general fats):

The general structure of a fat is glycerol, propane-1,2,3-triol. Attached to three fatty acids (alykl alcohol) by an ester bond at each of the three carbon of glycerol. These are what we consider common fats such as vegetable oils and animals fats. These are hydrophobic.

Phospholipid:

Same general structure of a triglyceride, but the one of the end carbons of the glycerol is attacked to a phosphate group (PO4). The other two carbons of course are attached to alkyl alcohols (fatty acids). The phosphate groups enables this molecule to be hydrophylic and hyrophobic at different ends (amphiphilic). The glycerol/phosphate group is considered the 'head' - hydrophilic - and the fatty acids are considered the 'tail' - hydrophobic.

Steroids:

Steroids are syntheisized from cholesterol, a macromolecule with 4 ring structure: three 6 carbon rings, and one 5 carbon ring attached to each other. They share a similar structure. They are hydrophobic like triglycerides.

Answer 2

A glyceride consists the glycerol which is polar and a non-polar tail (carbon chain). Phospholipids is similar to triglyceride but has one phosphate group. Steriods are a type of isoprenoid lipids.