When we begin to study Control, Coordination and Movement in Living Beings, we are not merely opening another chapter of biology—we are entering the very logic of life itself. Because if you pause and observe carefully, life is not defined only by structure or composition; it is defined by the ability to respond, regulate, and…
Every living organism—whether a tiny microbe or a human being—contains thousands of biomolecules working in harmony. But these molecules are not static; they are constantly being broken down and rebuilt through a series of chemical reactions. This dynamic process is called metabolism. Metabolism is not just a biochemical concept—it is the very essence of life….
Cholesterol To understand good cholesterol and bad cholesterol, we must first correct a very common misconception—cholesterol itself is not “good” or “bad.” What actually matters is how cholesterol is transported in the body. This transport is carried out by special biomolecules called lipoproteins. What are Lipoproteins? Lipoproteins are complex biomolecules made of lipids (fats) and…
When we talk about minerals, we are essentially referring to those inorganic elements that originate from soil and water, enter the food chain through plants and animals, and ultimately become indispensable for human survival. Unlike vitamins, minerals do not provide energy, yet they act as silent regulators of life, supporting everything from bone strength to…
Vitamins are organic compounds essential for normal metabolism, growth, and overall physiological functioning. Since the human body cannot synthesise most vitamins, they must be obtained through diet or supplements. A total of 13 vitamins are recognised, classified based on solubility, which directly influences their absorption, storage, and deficiency patterns. Classification of Vitamins Basis Fat-Soluble Vitamins…
Nucleic acids are one of the most fundamental biomolecules of life. If you ask a simple question—what makes you, you? —the answer ultimately lies in nucleic acids. They are responsible for: Structurally, nucleic acids are polymers, meaning they are long chains made up of repeating smaller units called nucleotides. Each nucleotide has three essential components:…
Lipids are organic compounds mainly composed of carbon (C), hydrogen (H), and oxygen (O), and sometimes phosphorus, nitrogen, or sulphur. The most important characteristic:👉 They are hydrophobic (water-insoluble) but soluble in non-polar solvents like alcohol, ether, and chloroform. Now pause and think: Why this behaviour? Because lipids are non-polar molecules—they lack charge separation. And in…
Proteins are polypeptides, meaning they are long linear chains of amino acids connected by peptide bonds. Think of them as beads (amino acids) arranged in a specific sequence to form a functional molecule. Unlike carbohydrates or lipids, proteins are heteropolymers, which means they are made up of different types of monomers (20 amino acids). This…
Carbohydrates are organic compounds made up of carbon (C), hydrogen (H), and oxygen (O), generally in the ratio 1:2:1, (CH2O)n. This ratio itself gives you a hint that carbohydrates are closely related to water chemistry (H₂O pattern), which is why they are often easily metabolised. They are also called saccharides (from the Greek word sakcharon,…
Nutrients are the fundamental substances required by living organisms to survive and function properly. Think of them as the input materials that keep the body running. They perform four essential roles: Classification of Nutrients Nutrients are broadly divided into two categories based on the quantity required by the body: (A) Macronutrients These are required in…
