Biology teacher

7.RESPIRATION – Notes for Students What is Respiration? Respiration is the process by which cells release energy from food (mainly glucose) with the help of oxygen. It is a biochemical process that happens inside the cells (cellular respiration) . Why is Respiration Important? After digestion and absorption, food is assimilated into the body. The assimilated food is used for: Energy production – to perform various life processes (movement, growth, repair, etc.). Growth and repair – to build new cells and tissues. Respiration helps to release energy stored in food to keep the organism alive. How Energy is Released? Food acts as the fuel . Oxygen reacts with glucose (a simple sugar) in the cells. This reaction is like a slow burning of glucose. Energy is released and stored in ATP (Adenosine Triphosphate) molecules. ATP is the energy currency of the cell – energy can be used whenever needed. Waste products: Carbon dioxide (CO₂) and Water (H₂O) are formed....

  EXCRETION IN ANIMALS Meaning Excretion → The process of removing waste products from the body. Waste materials are harmful if not removed. Main wastes: Carbon dioxide (CO₂) and Nitrogenous wastes (like urea , ammonia ). Excretion in Different Animals Amoeba (Single-Celled Animals) CO₂ → Removed by diffusion through the cell membrane. Nitrogenous wastes (ammonia) + Excess water → Removed by contractile vacuole . Earthworm Nephridia → Tubular excretory organs that remove nitrogenous wastes. Moist skin → Also helps in excretion. Humans Nephron → Functional unit of the kidney (about 1 million nephrons per kidney ). Kidneys → Main excretory organs, remove urea and other wastes. Removal of Waste in Humans 1. Lungs → Remove CO₂ CO₂ is produced during respiration (oxidation of food). From tissues → into blood → carried to lungs → exhaled through nostrils. Lungs = Excretory organs for respiratory waste. 2. Kidneys → Remove Urea Ure...

🌱 Nutrition and Food  1️⃣ What is Food? 👉 Definition: Food is an organic substance that gives us energy + building materials for our body. Simplest form: Glucose (a simple sugar) → like instant fuel for your body. Complex form: Starch (made of many glucose units) → stored energy. 🔎 Examples: Glucose → found in fruits, honey, energy drinks. Starch → wheat, rice, potatoes, bread. 📖 Story Trick: Imagine glucose is like cash 💵 (ready to use immediately), while starch is like money in the bank 🏦 (stored, needs to be broken down before use). 🧠 Mnemonic: “Glucose = Go now, Starch = Save for later.” 2️⃣ What are Carbohydrates? 👉 Definition: Carbohydrates are energy foods (main fuel for daily activities). Glucose + Starch belong to carbohydrates. They are the most common source of energy . 🔎 Examples: rice, bread, potatoes, cereals. 🧠 Mnemonic: C in Carbohydrate = C in Calories → "Carbs give calories." 📖 Story: Think of your body...