Question

Stimulant alkaloid present in tea is
A) Thebaine
B) Tannin
C) Caffeine
D) Both B and C

Answer 1

Alkaloids are secondary metabolites that are produced by plants. They are known to contain many natural bioactive compounds that play important roles in many biological processes. In humans they are used in different metabolic pathways and also as a stimulant.

Complete answer:
Alkaloids are known to be derived from amino acids and contain one or more nitrogen atoms in their structure. Presence of these nitrogen imparts alkalinity to these compounds. Alkaloids are generally colourless and odourless and have a bitter taste. Alkaloids are majorly present in plants to prevent them from several insects. The first alkaloid to be discovered was morphine from opium poppy. Alkaloids are known to have diverse effects such as antibacterial, anticancer, anti-inflammatory, analgesic and many more. Many alkaloids are even used in the development of modern medicine and drug discovery. Alkaloids are known to act as potent stimulants. They act on the central nervous system or the brain directly and increase their activities. Tea is a beverage that is widely consumed throughout the world. Earlier tea was used as a medicinal drink that helped to provide relief in several illnesses. The major component of tea is caffeine. It also contains polyphenols such as tannin and few amino acids that imparts flavour and colour. Tea has a stimulating effect on humans mostly due to the presence of caffeine.

Hence the correct answer is option (C) Caffeine.

Note: Alkaloids are important compounds that are required in many physiological processes but some of them are harmful as well and thus should not be consumed.