1. Procurement of nutrients is known as nutrition.
2. Nutrition are two types.
a) Autotrophic nutrition and
b) Heterotrophic nutrition.
3. In autotrophic nutrition, organisms make their own food from simple inorganic materials like CO2 and H2O using light as source of energy.
4. Heterotrophic nutrition involves intake of complex materials prepared by other organisms.
5. Photosynthesis is a process by which green plants are containing chlorophyll, produce food substances [glucose & starch] from CO2 and H2O using light as source of energy and release O2 into atmosphere.
6. C.B.Van Neil, 1931 proposed and formulated an equation for photosynthesis as
9. To destarch a leaf, potted plant has to be kept in dark room for 24 hours [it removes the starch already present in the leaf] and boil it in methylated spirit over water bath till it becomes pale white due to removal of chlorophyll.
10. If we add Iodine solution to the dechlorified leaf, it turns to blue – black colour indicating the presence of starch.
11. There are four essential factors of Photosynthesis viz. carbon dioxide, water, chlorophyll and sunlight.
12. In 1648, Von Helmont of Belgium found that water was essential for the increase of plant mass.
13. In 1770, Joseph Priestly revealed the essential role of air in the growth of plants.
14. Priestly discovered O2 in 1774, but the name oxygen was coined by Lavoisier in the year 1775.
15. Priestly experimentally proved that plants restore the air whatever breathing animals and burning candles remove.
16. In 1779, Jan Ingenhousz, a Dutch, experimentally proved that in bright sunlight, gas bubbles were formed around the hydrilla plant and it was Oxygen.
17. In 1883, Julius Von Sachs found that chlorophyll is present in the chloroplast.
18. In 1954, Daniel I.Arnon extracted chloroplast from plant cells, which could carry the photosynthesis.
19. The light reactions of occur in grana and dark reactions of photosynthesis occur in stroma of chloroplast.
20. The end products of light reaction are O2 ATP & NADPH2 and Glucose is the end product of dark reaction.
21. Important events occurring in chloroplast are:
- Conversion of light energy to chemical energy
- Splitting of water molecule
- Reduction of CO2 to carbohydrate
22. The form of nutrition differs depending on the availability and type of food as well as how it is obtained by the organism.
23. Some organisms break down the food materials outside the body and then absorb it.
Example: Bread Mould, Mushrooms, Yeast, etc.
24. Some organisms take down the whole material and break it down inside their bodies.
25. Some other organisms derive nutrition from plants or animals without killing them.
Example: Cuscuta, Lice, Leeches and Tapeworms.
26. In single celled organisms like amoeba, the food may be taken in by the entire surface but as the complexity of the organism increases, different parts become specialized to perform different functions.
27. The process of taking food inside the body is called ingestion.
28. The process of breaking complex substances into the simple substances, so that they can be used by the body with the help of the enzymes is called digestion.
29. Saliva secreted by three pairs of salivary glands contains an enzyme amylase (ptyalin), which helps in the breakdown of complex carbohydrates to simple ones.
30. The alimentary canal is basically a long tube that extends from the mouth to the anus.
31. The parts of human digestive system are mouth, buccal cavity, pharynx, esophagus, stomach, small intestine, large intestine, rectum and anus.
32. The digestive system includes the alimentary canal and several associated organs. The functions of system are as follows:
- Ingestion: Taking of food into the body.
- Digestion: Breaking up of complex food substances into simple substances so that they can be used by the body which will be carried out by specific enzymes.
- Absorption: The passage of directed food through the walls of alimentary canal into the circulatory system.
- Defecation: The passage of undigested material from the body through the way of anus.
33. Food mixed with saliva passes though the esophagus by wave like movements called peristaltic movements to the stomach.
34. In the stomach food gets churned with gastric juice and HCl.
35. Chyme is soft slimy substance in which some proteins and carbohydrates have already broken down.
36. The sphincters in the stomach allow only a small quantity of food to pass into the small intestine at a time.
37. The small intestine is the longest part of the alimentary canal where complete digestion of carbohydrates, proteins and fats takes place.
38. Small intestine receives bile juice from the liver and pancreatic juice from pancreas.
39. Bile juice emulsifies the fats, whereas trypsin and lipase of pancreatic juice digests proteins and fats respectively.
40. Finger-like projections formed from the walls of intestine are known as villi. They absorb the products of digestion and from villi into the blood vessels and lymph vessels.
41. The passage of undigested material from the body through anus is called defecation.
42. Indigestion is difficulty in digesting food. It is caused by stomach and duodenal ulcers.
43. Our diet should be a balanced one which contains proper amount of carbohydrates, proteins, fats, mineral salts and vitamins.
44. Eating of food that does not have one or more than one nutrients in required amount is known as malnutrition.
Malnutrition is of 3 types:
- Calorie malnutrition
- Protein malnutrition
- Protein Calorie malnutrition
45. Kwashiorkor disease occurs due to protein deficiency.
46. Marasmus is a disease caused due to both protein and calorie deficiency.
47. Obesity occurs due to overeating and excess of energy intake. Vitamins are micro nutrients required in small quantities. They are water soluble (B complex, Vitamin C) and fat soluble (Vitamin A, D, E and K).