Imagine That You Have Isolated a Mysterious Liquid from a Sample

question 16

Multiple Choice

Imagine that you have isolated a mysterious liquid from a sample of food. You add the liquid to a beaker of water and shake vigorously. After a few minutes, the water and the other liquid separate into two layers. To which class of biological molecules does the unknown liquid most likely belong?

• A) Carbohydrates
• B) Lipids
• C) Nucleic acids
• D) Enzymes
• E) Proteins

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Definitions:

Citric Acid Cycle

Cyclic pathway that harvests energy from acetyl–CoA; part of aerobic respiration. Also called the Krebs cycle.

Glycolysis

The metabolic pathway that converts glucose into pyruvate, generating ATP and NADH without the need for oxygen.

NADH

A coenzyme found in all living cells that is produced during glycolysis and used as an electron carrier in the process of cellular respiration.

FADH2

A redox cofactor involved in cellular respiration, acting as a carrier of electrons to the electron transport chain.