Problem 87 - Objective Biology for NEET

Question

Which one of the following are secondary metabolites? (a) Flavonoids and rubber (b) Antibiotics, coloured pigments and essential oils (c) Scents, gums, spices (d) All the above

Step-by-Step Solution

Answer

The correct answer is (d) All the above. All the compounds mentioned in the options are secondary metabolites.

Step 1: Understanding Secondary Metabolites

First, understanding what are secondary metabolites is crucial. They are compounds produced by an organism that are not essential to its survival but which often have important roles in its interaction with the environment.

Step 2: Identifying Secondary Metabolites in the Options

Next step is to identify secondary metabolites in the given options. Flavonoids, rubber, antibiotics, coloured pigments, essential oils, scents, gums, spices are all examples of secondary metabolites.

Step 3: Selecting the Correct Answer

As all the compounds in the options are secondary metabolites, the correct answer is (d) All the above

Key Concepts

Flavonoids

Flavonoids are a diverse group of phytonutrients found in many fruits and vegetables. They are known for their strong antioxidant properties, which contribute to their ability to combat oxidative stress.
These compounds play an essential role in plant survival by protecting against UV radiation. Humans can also benefit from flavonoids as they are linked to various health benefits, such as reducing the risk of heart disease.

• Protect plants against environmental stressors
• Offer potential health benefits for humans
• Are responsible for the vivid colors in fruits and vegetables

Antibiotics

Antibiotics are a type of secondary metabolite with significant applications in medicine. These compounds are produced by certain bacteria and fungi to inhibit the growth of other microorganisms.
This ability to ward off bacteria makes antibiotics crucial in treating bacterial infections, revolutionizing health care by reducing mortality rates from infectious diseases. However, their overuse has led to the development of antibiotic-resistant bacteria.

• Produced naturally by microorganisms
• Inhibit the growth of harmful bacteria
• Major tool in combating infectious diseases

Coloured Pigments

Coloured pigments found in plants are secondary metabolites that serve multiple roles. Not only do they provide vibrant colors to flowers, helping in pollination by attracting insects, but they also have protective functions.
These pigments can protect against harmful UV rays and predators, such as herbivores and pathogens.

• Attract pollinators with vivid colors
• Provide protection against UV radiation
• Act as a defense mechanism against predators

Essential Oils

Essential oils are concentrated liquids containing volatile aroma compounds from plants. They help in plant defense against insects and bacteria, and some speculate they may help in communication with other organisms.
In aromatherapy, essential oils are used for their therapeutic properties, contributing to relaxation, improved mood, and overall well-being.

• Volatile and aromatic in nature
• Serve as a defense mechanism for plants
• Used in aromatherapy for potential therapeutic effects

Scents

Scents in plants are a direct result of secondary metabolites, primarily terpenes and esters. They play a crucial role in attracting pollinators and deterring herbivores.
For humans, these scents are exploited in the fragrance industry, contributing to a wide range of perfumes and scented products.

• Attract pollinators through pleasant odors
• Deter herbivores and protect plants
• Widely used in the fragrance industry

Gums

Gums are plant polymers that serve as secondary metabolites, often released in response to injury. They help in sealing wounds, preventing infection, and deterring herbivores by toughening or stickifying affected areas.
In the food and cosmetic industries, gums are valued for their thickening and stabilizing properties.

• Seal plant wounds and prevent infections
• Act as a defense against herbivores
• Used in food and cosmetics for textural purposes

Spices

Spices, derived from different parts of plants like seeds, bark, roots, and fruits, are rich in secondary metabolites. These compounds provide spices their unique flavors and aromas.
Historically, spices have been valued not only for culinary uses but also for their antimicrobial properties, which help preserve food and enhance its safety.

• Impart flavor and aroma to food
• Contain compounds with antimicrobial properties
• Used in food preservation throughout history