1. Life and living Andries Olivier p 1

2. Andries Olivier p 1 Microorganisms 3. Andries Olivier p 1 The existence of microorganisms Living organisms which are too small to be seen with the naked eye. You need a 4. Andries Olivier p 1 The existence of microorganisms Extremely small in size. Numverous. Numverous. Numerous.Numverous. Numverous. Numerous.Numverous. Numverous. Numerous.Numverous. Numverous. Numerous.Numverous. Numverous. Numerous.Numverous. Numverous. Numerous.Numverous. Numverous. Numerous.Numverous. Numverous. Numerous.Numverous. Numverous. Numerous.Numverous. Numverous. Numerous.Numverous. Numverous. Numerous.Numverous. Numverous. Numerous.Numverous. Numverous. Numerous.Numverous. Numverous. Numerous.Numverous. Numverous. Numerous.Numverous. Numverous. Numerous.Numverous. Numverous. Numerous.Numverous. Numverous. Numerous.Numverous. Numverous. Numerous.Numverous. Numverous. Numerous.Numverous. Numverous. Numerous.Numverous. Numverous. Numerous.Numverous. Numverous. Numerous.Numverous. Numverous. Numerous.Numverous. Numverous. Numerous.Numverous. Numverous. Numerous.Numverous. Numverous. Numerous.Numverous. Numverous. Numerous.Numverous. Numverous. Numerous.Numverous. Numverous. Numerous.Numverous. Numverous. Numerous.Numverous. Numverous. Numerous. Numerous Extremely important to 5. Andries Olivier p 1 The existence of microorganisms They play an important role in the decomposition of dead plants and animals, causing dead matter to decay and spoil. 6. Andries Olivier p 1 The existence of microorganisms Some are useful, others are harmful. Cause diseases in animals, humans and plants. 7. Andries Olivier p 1 The existence of microorganisms There are three main types: viruses bacteria fungi 8. Andries Olivier p 1 Viruses Smaller than fungi and bacteria. You need a powerful electron microscope to see them. They are not true cells: they cannot reproduce on their own. They can only reproduce once they are inside a hosts' cells. This causes the host to become ill because their cells become damaged. Influenza Measles Common cold Chicken pox Fever blisters AIDS 9. Andries Olivier p 1 Bacteria Bigger than viruses, but still VERY small. Found everywhere. Most are harmless to humans and play important roles in food webs. Those that do, cause disease enter human cells and use the cells to feed while giving off poisons. 10. Andries Olivier p 1 Fungi Fungal cells 10 100 times bigger than bacteria cells. Many different types, shapes and sizes. Yeast small, unicellular: used to bake bread. Mould very thin threads (furry/woolly): grows on stale bread and overripe fruit. Mushrooms and toadstools larger and grow in soil or in compost. 11. Andries Olivier p 2 Reproduction Make replicas of themselves and multiply in minutes/seconds. They damage the hosts' cells or give off toxins. Only after many cells have been damaged, or large amounts of toxins have built up, does the host get sick. 12. Andries Olivier p 2 Role Maintain soil fertility Purify water Digest food in humans and animals 13. Andries Olivier p 2 Useful microorganims Decomposing bacteria help to break down animal and plant material. Nutrients return to the soil. 14. Andries Olivier p 2 Useful microorganims 15. Andries Olivier p 2 Useful microorganisms Some ruminants have bacteria in their stomachs that help to digest grass. Also used to produce dairy products. Yeast = unicellular fungi. Used in baking bread. One adds yeast to the dough, which respires and forms small bubbles of CO2. (Which allows the bread to rise.) Yeast also ferments alcoholic drinks such as beer and wine. 16. Andries Olivier p 3 Antibiotics ...are manufactured by using microorganisms. ...used to destroy other disease-causing bacteria or prevent them from reproducing. ...containing penicillin are produced using penicillin fungus. Certain antibiotics originate from bacteria. 17. Andries Olivier p 3 Antibiotics ...can cause allergic reactions in some people. Everyone has 'good' bacteria in their digestive systems it helps to destroy dangerous/harmful bacteria. Dangerous bacteria can affect the digestive system, causing an upset tummy. 18. Andries Olivier p 3 Harmful organisms Once inside the body, they multiply quickly. Can cause disease in two ways: Destroy cells Give off poisonous chemicals called toxins The effect of microorganisms on the body are called symptoms. Microorganisms which cause diseases are called pathogens. 19. Andries Olivier p 3 HIV and AIDS HIV infects a person when they have unprotected sex with an infected person of when blood from and infected person enters the body of another person. An infected mother can pass HIV to her unborn child, or through breastfeeding. If someone is infected with the HI virus we say that they are HIV positive. 20. Andries Olivier p 3 HIV and AIDS HIV attacks the body's immune system. (The bodies' defence system, protecting the body by fighting diseases.) HIV enters the cells of the immune system (called T cells), destroys the cells and weakens the immune system. The immune system cannot combat diseases when it is weakened. The person will be ill more often. 21. Andries Olivier p 3 HIV and AIDS Over the years the virus attacks so many cells that the immune system eventually no longer works and is no longer able to protect the body against serious illnesses. At this point we say the person has AIDS. TB and pneumonia are bacterial infections which often affect people with AIDS. It can take a few years for the HI virus to weaken a person's immune system, so the person can appear healthy for a long time although they are HIV positive. 22. Andries Olivier p 3 Resistance to medicines Harmful microorganisms can be destroyed by white blood cells. White blood cells can: Ingest and digest microorganisms. Produce antibodies that attach microorganisms. These destroy or collect them which enables them to be engulfed quicker. Destroy toxins manufactured by harmful organisms. 23. Andries Olivier p 3 White cells also produce memory cells, which stay in the blood for a very long time, and can recognise pathogens which enter the body. These cells helps a person to attack the disease quickly, so that person does not suffer the same symptoms again. A person is now immune. Each type of antibody is specialised. When a mixture of organisms infects a body, many different antibodies are required to help with healing. Medical remedies are used to help combat microorganisms. However, microorganisms can mutate, developing resistance to the medicines, so they spread much quicker. 24. Andries Olivier p 8 The structure of living things 25. Andries Olivier p 8 Cells and systems All living things consist of really small particles called cells. Cells are the basic unit of which living organisms consist. 26. Andries Olivier p 8 Cells and systems All cells have the same basic structure, but differ according to their function, and from which part of the organism they originate. Groups of cells with the same structure and function are known as tissues. 27. Andries Olivier p 8 Cells and systems So the progression is: Atoms Molecules Cells Tissues Organs Systems Organism 28. Andries Olivier p 8 Cells and systems Since cells are very small, we need to use a microscope to see cells. 29. Andries Olivier p 8 Microscope 30. Andries Olivier p 9 Microscope Also ocular: Lens where you put your eye, enlarges the object (10x). Holds objectives with low- and high-power lenses rotating disc. Lenses of the objectives help to enlarge the image. Also platform: Supports the microscope slide opening which transmits light from the mirror or electric light source below. 31. Andries Olivier p 9 Microscope Controls the amount of light directed onto and passing through the object; focuses light rays from the mirror or light source onto the object. Reflects light upwards through the condenser towards the opening in the stage. Used for final focus to get a clear image. 32. Andries Olivier p 9 Microscope tube arm Coarse adjustment knob 33. Andries Olivier p 9 Microscope Magnification: If the magnifying power of the eyepiece is 10x and the objective is 40x, the the total magnification of the object being viewed is 10 x 40; or 400x Microscope slide: Consists of a glass slide, the object (specimen and a cover-slip. 34. Andries Olivier p 9 Cell structure Cell membrane: covers the cell Cytoplasm: the living substance, contains all organelles. Viscous liquid. Nucleus: controls the functions of the cells. Largest organelle in the cell. Vacuole: organelle with a membrane that holds liquid. 35. Andries Olivier p 9 36. Andries Olivier p 10 37. Andries Olivier p 10 PLANT CELLS Firm shape because of a cell wall. One or two large, permanent vacuoles. The green pigment called chloroplasts. ANIMAL CELLS Flexible shape because it has no cell wall. Many small vacuoles, in any at all. No green pigment called chloroplasts. 38. Andries Olivier p 10 Both types of cells have... cytoplasmcell membrane a nucleus 39. Andries Olivier p 17 Life processes and systems 40. Andries Olivier p 17 Parts and systems Digestive system Mouth Oesophagus IntestinesNutrition 41. Andries Olivier p 17 Parts and systems Respiratory system Trachea Lungs DiapraghmRespiration 42. Andries Olivier p 17 Parts and systems Excretory system Kidneys Lungs SkinRespiration 43. Andries Olivier p 17 Parts and systems Reproductive system Penis and testes (males) Vagina, ovaries and uterus (females)Reproduction 44. Andries Olivier p 17 Parts and systems Nervous system Brain Spinal cord Sense organsSensitivity 45. Andries Olivier p 17 Parts and systems Locomotory system Bones Muscles Movement 46. Andries Olivier p 17 Parts and systems Circulatory system Heart Blood vessels Transportation 47. Andries Olivier p 19 Nutrition 48. Andries Olivier p 19 The process by which living organisms take in food and use it for energy, growth and repair. 49. Andries Olivier p 19 Required growth energy K health N Repair and replacement of worn and damaged tissue 50. Andries Olivier p 19 Nutrient Function Proteins Growth and repair building blocks Carbohydrates Instant energy source Fats Reserve energy source and insulation against the cold Vitamins Ensures normal growth and development. Health. Minerals Ensures normal growth and development. Water Main ingredient of your body. Supplies fluid medium for metabolic processes. Fibre Prevents constipation and certain cancers. 51. Andries Olivier p 20 Digestion Breaking down of organic food compounds to their simplest forms. Food is made up of really large molecules which cannot be absorbed into the blood or cells because of their size. Cells need protein to be made smaller into amino acids, carbohydrates into glucose and fats into glycerol and fatty acids. 52. Andries Olivier p 20 Digestion Mechanical digestion: Teeth tear, chew, grind Stomach stir, grinds and mixes Chemical digestion: Digestive enzymes break food down chemically 53. Andries Olivier p 21 Human digestive system Made up of: Mouth Oesophagus Stomach Small intestines Large intestines 54. Andries Olivier p 21 Teeth Biting, chewing grinding food Tongue Keep food between teeth Mixed food with saliva Moulds food into bolus Assists with swallowing Salivary glands Secrete saliva Keep food moist Form a bolus Oesophagus Peristalsis: pushes bolus to stomach by means of peristalsis no digestive function. Stomach Muscular wall grinds food finely and mixes it with digestive juices (mechanical digestion). Stomach juices start breaking down proteins (chemical digestion). Liver Produces bile Bile digests fatty acids Gall bladder Temporarily stores bile Pancreas Produce digestive juice with enzymes that break down proteins, fats and carbohydrates. Small intestine Secretes intestinal juice containing enzymes Enzymes digest food substances Contains villi Absorbs digested food substances Large intestine Stores undigested food temporarily. Absorbs water, mineral salts and some vitamins. Bacteria decompose digested food to faeces which leaves the body through the anus. 55. Andries Olivier p 21 Teeth 56. Andries Olivier p 22 Teeth functions Incisors and canines: Bite and tear food Premolars and molars: Grind the food 57. Andries Olivier p 22 Tongue 58. Andries Olivier p 22 Tongue functions Contains taste buds is a taste organ. Helps with chewing moves food under teeth, makes a bolus, assists in swallowing. 59. Andries Olivier p 22 Salivary glands 60. Andries Olivier p 22 Salivary glands types Parotid glands (ear salivary glands) Submaxillary glands (lower jaw glands) Sublingual glands (under tongue salivary glands) 61. Andries Olivier p 22 Salivary glands functions Contains ptyalin (enzyme) digests cooked starch. Slimy smooths the finely chewed food, makes swallowing easy. Alkaline and neutralises food and helps with the prevention of food decay. 62. Andries Olivier p 22 Oesophagus 63. Andries Olivier p 23 Stomach Takes 3 hours for food to change into chyme. Chyme = grey coloured liquid mass of food that has been changed as a result of the grinding and breaking down digestive processes. 64. Andries Olivier p 23 Stomach - functions Store food temporarily Grind food even finer Stomach walls secrete gastric juices to break down food to smaller forms Pyloric valve allows small amounts of chyme to go to small intestine Some food that are already small enough is absorbed 65. Andries Olivier p 23 Small intestine Elastic, muscular tube, approximately 5 m long folded up. Held in place by membranes attached to the walls of the abdominal cavity. Divided into three regions: Duodenum Jejenum Ileum 66. Andries Olivier p 23 Small intestine - function Glands secrete intestinal juices (enzymes). Not fully digested food are completely digested. Absorption of digested food takes place here. 67. Andries Olivier p 23 Villi 68. Andries Olivier p 23 Large intestine 1,5 m long and 70 mm wide Caecum leads into the appendix causing appendicitis. Colon forms the largest part. Stores food Rectum ends in the anus from where faeces is expelled. 69. Andries Olivier p 23 Large intestine - functions Stores faeces temporarily Glands in the wall secrete mucous to assist the movement of the faseces. Water, mineral salts and certain vitamins are absorbed from the contents 70. Andries Olivier p 23 Balanced diet 71. Andries Olivier p 24 Malnutrition Incorrect nutrition Poor people undernutrition Rich people overnutrition 72. Andries Olivier p 24 Undernutrition When someone does not take up enough of one or more of the food groups. Sometimes caused by traditional eating habits, excessive strict diets or of pure ignorance. 73. Andries Olivier p 24 Deficiency diseases Symptoms Causes Rickets Bones soften and break Shortage of vit. D. Scurvy Bleeding gums, low resistance to infectious diseases. Shortage of vit. C. Night blindness Inability to see in poor light. Shortage of vit. A. Beri-beri Nerve and heart problems. Weakened muscles; paralysation. Shortage of vit. B1 . Goitre Enlarged thyroid gland. Shortage of iodine. Anaemia Tiredness, weakness, decreased oxygen supply. Shortage of iron. 74. Andries Olivier p 24 Deficiency diseases Symptoms Causes Kwahiorkor Bloated stomach and swollen cheeks. Skin cracks and peels. Shortage of proteins. Marasmus Loss of muscle and the body becomes thin and weak. Drastic loss of mass, diarrhoea. Diet low in kilojoules and proteins. Starvation. Pellagra Cracked, dry skin (especially cheeks), digestive diseases. Shortage of B- group vitamins. In young children due to malnutrition 75. Andries Olivier p 24 Other illnesses Anorexia nervosa Bulimia nervosa Overnutrition