What is caffeine?

What is caffeine?

• A. A protein enzyme.
• B. A lipid.
• C. A central nervous system stimulant found in coffee and tea.
• D. A vitamin.

Answer: (C)

Caffeine is a central nervous system stimulant, commonly consumed in coffee and tea. It is a small alkaloid molecule, not a protein enzyme, not a lipid, and not a vitamin. Its stimulatory effect comes from blocking adenosine receptors in the brain, which reduces fatigue and increases alertness by boosting neuron activity and neurotransmitter release. This mechanism explains why coffee and tea make people feel more awake, rather than being a protein catalyst, a fat, or a vitamin.

Caffeine is a central nervous system stimulant, commonly consumed in coffee and tea. It is a small alkaloid molecule, not a protein enzyme, not a lipid, and not a vitamin. Its stimulatory effect comes from blocking adenosine receptors in the brain, which reduces fatigue and increases alertness by boosting neuron activity and neurotransmitter release. This mechanism explains why coffee and tea make people feel more awake, rather than being a protein catalyst, a fat, or a vitamin.