Question

which functional groups are present in lipids? see figures below. if you are having trouble seeing the figure then click this link to see the figure in a new window: lipid functional groups need a hint? check out this version of the figure that has all of the functional groups circled: lipid functional groups circled ☐ amino ☐ carboxyl ☐ phosphate ☐ hydroxyl ☐ sulfhydryl ☐ methyl

Explanation:

1. Carboxyl: Fatty acids (a component of lipids like triglycerides) have a carboxyl group ($-COOH$) at one end.
2. Phosphate: Phospholipids (a type of lipid) have a phosphate group in their polar head region.
3. Hydroxyl: Glycerol (which combines with fatty acids to form lipids like triglycerides) has hydroxyl groups ($-OH$).
4. Methyl: Methyl groups ($-CH_3$) are present in the hydrocarbon chains of fatty acids and in steroid lipids (like cholesterol) as seen in the structures.

Amino groups ($-NH_2$) are not typical of lipids (they are in amino acids/proteins), and sulfhydryl groups ($-SH$) are also not characteristic of lipids.

Answer:

• Carboxyl
• Phosphate
• Hydroxyl
• Methyl