PowerPoint Presentation: Life Processes NUTRITION Dhriti Behl X B 17 In Plants and animals PowerPoint Presentation: NUTRITION The process by which living organisms take in Food and use it to obtain energy for growth and Development is called nutrition PowerPoint Presentation: There are two types of nutrition PowerPoint Presentation: Autotrophic Nutrition Autotrophic organisms require carbon and energy which are fulfilled by photosynthesis. It is a process by which autotrophs take in substances from outside and convert them into stored forms of energy. This material is taken in the form of carbon dioxide and water Which is converted into carbohydrates in the presence of sunlight and chlorophyll. Carbohydrates are utilized for providing energy to the plant. The carbohydrates which are not used immediately are stored in the form of starch. PowerPoint Presentation: A cross section of a leaf If you carefully observe a cross section of a leaf under the Microscope you will notice that Some cells contain green dots. These dots are cell organelles called Chloroplasts which contain chlorophyll. PowerPoint Presentation: Stomatal Pore The tiny pores present on the surfaceOf the leaves are called stomata. Massive amounts of gaseous Exchange takes place in the leaves Through these pores for the purpose Of photosynthesis. Since large amounts of water can also be lost through these stomata, the plant Closes its pores when it does not need carbon dioxide for photosynthesis. The opening and closing of the pore is a function of the guard cells. The guard cells swell When water flows into them, causing the stomatal pore to open. Similarly the pore closes When the guard cells shrink. PowerPoint Presentation: Heterotrophic nutrition PowerPoint Presentation: Each organism is adapted to its environment. The form of nutrition differs depending on the type and availability of the food material as well as how it is obtained by the organism . Heterotrophic nutrition There is a range of strategies by which the food is taken in and used by the organism. Some organisms break down the food material outside and then absorb it. Examples Are fungi like bread moulds , yeast and mushrooms . Others take in whole material and break it down inside their bodies. What can be taken down and broken depends on the body design and Functioning. Some other organisms derive nutrition from plants or animals without killing them. This parasitic Nutritive strategy is used by a wide variety of organisms like cuscuta , ticks , lice , leeches and tape worms. PowerPoint Presentation: How do organisms obtain their nutrition ? Since the food and the way it is obtained differ , the digestive system is different in various organisms. In single-celled Organisms, the food maybe taken in by the entire surface. But As the complexity of the organism increases, different parts Become specialized to perform different functions. For example, Amoeba takes in food using temporary finger-like extensions of The cell surface which fuse over the food particle forming a food-vacuole. Inside the food-vacuole, complex substances are broken down Into simpler ones which then diffuse into the cytoplasm. The remaining undigested material is moved to the surface of the cell And thrown out. PowerPoint Presentation: Nutrition in Human Beings The human alimentary canal The long tube extending from the mouth to the Anus is called the alimentary canal. Saliva wets the food and makes it easy to digest. The food we ingest has to be broken down into simpler molecules. It is done with the help of biological catalyst called enzymes. The saliva contains an enzyme called salivary amylase that breaks Down starch to sugar. The lining of canal has muscles that contract rhythmically in order to Push the food forward. These peristaltic movements occur all along The gut. From the mouth the food is taken to the stomach through the Food-pipe or oesophagus. The stomach expands when food enters it. The muscular walls of the stomach help in mixing the food with more Digestive juices. The digestion functions are taken care by the gastric glands present in the walls of the stomach. The gastric glands Contain hydrochloric acid , a protein digesting enzyme called pepsin, and mucus. The mucus protects the inner lining of the stomach from the action of acid under normal conditions. PowerPoint Presentation: The exit of food from the stomach is regulated by a sphincter muscle which releases it in small amounts into the small intestine. Small intestine is the longest part of the alimentary canal which is fitted into a compact space because of extensive coiling. Herbivores eating grass have longer small intestine to allow the cellulose to be Digested. Carnivores have shorter small intestine as meat is easier to digest. The small intestine is the site of complete digestion of carbohydrates, proteins and fats. The food coming from the stomach is acidic and has to be made alkaline for the Pancreatic enzymes to act. Bile juice from the liver accomplishes this in addition. Fats are present in the intestine in the form of large globules which make it difficult For the enzymes to act on them. Bile salts break them down into smaller globules increasing the efficiency of enzyme action. The pancreas secrets pancreatic juice which contain enzyme like trypsin for digesting proteins and lipase for breaking down Imulsified fats. The walls of the small intestine contains glands which secretes intestinal juice. The enzyme present init finally convert the The protein into amino acids, complex carbohydrates into glucose and fats into fatty acids and glycerol. The inner-lining of the small intestine has numerous finger-like projections called the villi which increase the surface area for absorption. The villi are richly supplied with blood vessels which take the absorbed food to each and every cell of the body, where it is Utilized for obtaining energy, building up new tissues and the repair of new tissues. The unabsorbed food is sent to the large intestine where more villi absorb water from this material. The rest of the material is removed from the body via the anus. The exit of this waste material is regulated by the anal sphincter. PowerPoint Presentation: Acknowledgement I Dhriti Behl would like to thank my teachers and friends for their contribution in this project . I’d specially like to thank my Biology teacher for giving me this opportunity to make a presentation On the topic life processes. THANK YOU !! PowerPoint Presentation: Bibliography All the pictures are taken from the internet Google images and the written material from the N.C.E.R.T. book.