What are Life Processes? Life processes encompass a set of interconnected activities within an organism that collectively contribute to its repair and maintenance. These crucial processes include Respiration (R), Exeretion (E), Nutrition (N), and Transportation (T), forming the acronym RENT. Nutrition is the transformative process by which on organism acquires external sources of energy, commonly known as food, and transfers it internally for sustenance and vitality Respiration: The process of acquiring oxygen from outside the body, and using it in the process of break-down of food sources for cellular needs, is called respiration. Transportation refers to the internal mechanism responsible for conveying nutrients and oxygen from one location to another within the body. Excretion is the process through which the body eliminates and expels waste by-products, ensuring their removal from the internal environment and subsequent disposal outside the organism. * Modes of Nutrition 1. Autotrophic Nutrition. 2. Heterotrophic Nutrition. Autotrophs are organisms that derive their nutrition from basic food materials acquired from inorganie sources such as carbon dioxide and water. Notable examples include green plants and certain bacteria, Heterotrophs, on the.other hand, rely on complex substances for their nutritional needs. These intricate compounds must undergo breakdown into simpler forms before being utilized for the maintenance and growth of the organism. To facilitate this process, organisms employ bio-catalysts known as enzymes. Animals and fungi are examples of heterotrophs. Autotrophic Nutrition: St 1.Autotrophic organisms fulfill their carbon and energy requirements through photosynthesis. 2.Photosynthesis is the process whereby cutotrophs absorb external substances and convert them into stored energy. This involves the conversion of carbon dioxide and water into carbohydrates in the presence of sunlight and chlorophyll. 3. Surplus carbohydrates produced through photosynthesis are stored in the form of starch 4 Similarly, in our bodies, a portion of the energy derived from the food we. eat is stored in the form of glycogen. Chlorophyll ‘ — 6CO, +12H,0—Chlowptyll_.6,13,,0, +60, +6H,0 {Glucose}Events Occurring during Photosynthesis: 1.Chlorophyll absorbing light energy. 2. Transformation of light energy into chemical energy. 3.Separation of water molecules into hydrogen and oxygen. 4.Conversion of carbon dioxide into carbohydrates through reduction. Chlorophyll is a crucial component for the process of photosynthesis. The iodine test results in a blue-black coloration in the leaf regions where photosynthesis occurs. How the plant obtains carbon dioxide? Massive gaseous exchange occurs in leaves via stomatal pores for photosynthesis. Gas exchange extends across the surfaces of stems, roots, and leaves. ‘Stomatal pores close to prevent excessive water loss when carbon dioxide is not needed for photosynthesis. The opening and closing of stomatal pores are regulated by guard cells. Guard cells swell with water influx, causing stomatal pores to open. Conversely, the pores close when guard cells shrink, co, Stomata ys x ‘Stomata, porés on leaves, facilitate gas exchange. Predominantly located on the underside of leaves. Guard cells, regulating pore opening and closing, safeguard each stoma. The functionality of guard cells is influenced by their water content. —Crloropacts Guard Cet Coll Wat (2) Stoma Closed (©) Stoma open,Heterotrophic Nutrition: «_s~ £4. Saprophytic Nutrition Saprophytic nutrition refers to the feeding behavior of certain organisms that rely on consuming dead and decomposed organic matter. The food is partially digested outside the body, and then it is absorbed. E.g. Fungi are saprophytes. Parasitic Nutrition Parasitic nutrition involves organisms feeding at the expense of another, causing harm, Parasites live on or within a host organism, extracting nutrients directly from the host's body. Examples include leeches as ectoparasites, Ascaris as an endoparasite, and Cuscuta as a parasitic plant. Holozoic Nutrition: In holozoic nutrition, the digestion happens inside the body of the organism i.e., after the food is ingested. Most of the animals follow this mode of nutrition, How do Organisms obtain their Nutrition? Single-celled organisms Nucleus Amoeba engulfs food through temporary male extensions of its cell surface). creating a food- « er vacuole as these extensions merge over the food particle, 4 eee Within the food-vacuole, complex substances underge breakdown into simpler ones, facilitating Food vacuole their diffusion into the cytoplasm. Undigested material is transported to the cell surface and expelled by Amoeba. S Food particle @ Paramoecium, a unicellular organism, maintains a distinct shape and ingests food at a designated location. The entire cell surface, covered with cilia, facilitates the movement of food to the specified intake spot.Nutrition in Human Beings: « The alimentary canal is a lengthy tube running from the mouth to Tongue the anus. Degngn Salivary glands secrete saliva, which contains the enzyme e salivary amylase, breaking down oxi sss complex starch into simple —_— sugars, “ Muscles lining the canal contract " rhythmically, facilitating peristaltic movements that push sia food forward throughout the ttamahagtn gry carat digestive system. . Digestion in the stomach: © Gastric glands within the ston the enzyme pepsin, and mucu Hydrochloric acid establish effectiveness of the protein-d wall secrete hydrochloric acid, iment, enhancing the , pepsin, Under normal conditions, mucus from the corrosive effects of. * Pepsin functions as ap Length of small intestine: * Herbivores, such as those consuming grass, require an elongated small intestine to facilitate the digestion of cellulose. * Carnivores, like tigers, with a diet of easily digestible meat, possess shorter small intestines. ‘The small intestine serves as the location for the thorough digestion of carbohydrates, proteins, and fats. + Secretions from the liver and pancreas contribute to the digestive processes occurring in the small intestine.Bile juice from the liver: * Bile salts play a role in emulsifying fats, breaking large fat globules into smaller ones, thereby enhancing the efficiency of pancreatic enzymes. + The initially acidic food entering the small intestine undergoes alkalization through the action of bile juice, promoting the effectiveness of pancreatic enzymes. pancreatic juice from the pancreas: © Pancreatic juice includes enzymes such as trypsin, responsible for protein digestion, and lipase, which is involved in breaking down emulsified fats. © The small intestine walls house glands producing intestinal juice. ¢ Enzymes in the intestinal juice convert proteins to amino acids, complex carbohydrates to glucose, and fats to fatty acids and glycerol. © The inner lining of the small intestine has numerous finger-like projections called villi. Functions of Villi: * Enhances the surface area available for absorption. * Villi are abundantly supplied with blood vessels, facilitating the distribution of absorbed nutrients to every cell in the body. Unabsorbed food is directed to the large intestine, where its walls extract additional water from the material.