Quiz

QUIZ

1. What type of molecule is a triglyceride?

a. A tri-alcohol b. An alcohol aldehyde c. A tri-aldehyde d. A tri-ester

Answer: d. Triglycerides are fatty acids linked with an ester linkage three times to the same alcohol-based molecule.

2. What type of molecule is glycerol?

a. A diester b. A tri-alcohol c. A tri-ester d. An alcohol

Answer: b. Glycerol is a tri-alcohol molecule that is used extensively in lipid biochemistry even though it is not a lipid molecule itself and is otherwise polar in organic chemistry.

3. About how many carbon atoms are there in a fatty acid typically seen in nature?

a. 6-8 b. 10-12

c. 12-20 d. 24-28

Answer: c. Almost all fatty acids seen in nature have 12-20 carbon atoms to the fatty acid chain. There are several different fatty acids to remember that exist in nature.

4. Which fatty acid is considered the longest among the known and common fatty acids?

a. Stearic acid b. Arachidonic acid c. Palmitic acid d. Myristic acid

Answer: b. The longest naturally-occurring fatty acid is arachidonic acid, which is a 20-carbon carboxylic acid. All of them are between 12 and 20 carbon atoms in length.

5. What is the substance known as biofuel or biodiesel?

a. Aldehydes of unsaturated fatty acids b. Ethers made from combining fatty acids c. Methyl or ethyl esters of fatty acids d. Alkanes or alkenes made from fatty acids

Answer: c. Biodiesel or biofuel is the methyl or ethyl esters of fatty acids, made through the transesterification process.

6. What is not true of a micelle?

a. It is hydrophobic on the inside and hydrophilic on the outside. b. It is polar on the outside and nonpolar on the inside. c. It is the side chain that is the nonpolar end. d. It is the carboxylic acid end that is nonpolar.

Answer: d. It is the carboxylic end that is polar and the long side chain that is the nonpolar end. The micelle will be hydrophobic on the inside and hydrophilic on the outside. This translates to polar on the outside and nonpolar on the inside. These micelles are seen in soaps.

7. What is the fatty acid that makes up prostaglandins?

a. Linoleic acid b. Linolenic acid c. Arachidonic acid d. Oleic acid

Answer: c. Arachidonic acid is a 20-carbon atom molecule that has multiple double bonds that is used to make prostaglandins.

8. The terpenes are ultimately made by adding together which molecule?

a. Butane b. Pentene c. 2-pentenol d. Isoprene

Answer: d. Isoprene is the molecule that terpenes are made from. Isoprene goes by the IUPAC name of 2-methyl 1,3-butadiene.

9. What is not true of the structure of a steroid?

a. It contains 3 hexane rings b. It contains one pentane ring c. It is considered a terpene molecule d. It has a resonant ring

Answer: d. These are molecules that contain three hexane rings, one pentane ring, but no resonant ring associated with it, although it can have double bonds associated with the ring in some form.

10. Numbering a steroid molecule is difficult. By convention, how are these molecules numbered?

a. Starting at the pentane ring b. Starting at the top of the A hexane ring c. Starting at the first substituent or side chain d. Starting from the right-hand side of the molecule as written

Answer: b. The numbering system starts at the top of the A hexane ring, and goes in a specific order until all carbons are numbered, ending at the far right-hand side of the molecule as written.