Enzymes are biological catalysts that speed up chemical reactions in living organisms. They are primarily composed of proteins, which are made up of amino acids folded into specific three-dimensional structures. This structure is crucial because it determines the enzyme’s active site, where substrates bind and reactions occur. Enzymes are highly specific, meaning each enzyme typically catalyzes a particular reaction. Vitamins and minerals may act as cofactors or coenzymes, assisting enzyme function, but they are not the main structural components. Carbohydrates do not form enzymes. Thus, proteins are the correct answer. This concept is fundamental in biochemistry and helps explain how metabolic processes occur efficiently in living organisms.

Pepsinogen is activated by stomach acid into pepsin, which digests proteins into peptides.

Attock Fort was built by the Mughal Emperor Akbar in 1581. It is located near the Indus River in present-day Pakistan and was constructed for strategic military purposes. The fort played a crucial role in defending the northwestern frontier of the Mughal Empire against invasions from Central Asia. Akbar was known for strengthening the empire through administrative reforms and military infrastructure. Attock Fort was part of his broader strategy to secure trade routes and maintain control over key regions. Babur founded the Mughal Empire but did not build this fort. Sher Shah Suri was known for road construction, including the Grand Trunk Road, while Aurangzeb ruled later and did not construct Attock Fort. Thus, Akbar is the correct answer. The fort remains an important historical and architectural landmark in Pakistan today.

Karakoram Highway length is about 1600 km connecting Pakistan and China.

The International Day to Combat Desertification and Drought is observed annually on 17th June. This day was established by the United Nations to raise awareness about land degradation, desertification, and drought, which affect millions of people worldwide. Desertification refers to the degradation of land in arid and semi-arid regions, often caused by deforestation, overgrazing, poor irrigation practices, and climate change. It leads to reduced agricultural productivity, food insecurity, and displacement of populations. The observance encourages governments, organizations, and individuals to adopt sustainable land management practices. It also promotes international cooperation to address environmental challenges. The other dates mentioned are incorrect because the UN officially designated 17th June for this purpose. Recognizing such international days is important in exams as they reflect global awareness campaigns. Therefore, 17th June is the correct answer, highlighting efforts to combat environmental degradation and ensure sustainable land use.