SUBJECT: SCIENCE FORM: 5TOPIC: MICROORGANISMS AND THEIR EFFECTS ON LIVING THINGS CLASSIFICATIONS OF MICROORGANISMSo Type of microorganisms- Definition: Tiny living things that cannot be seen by naked eyes, but can be seen by electron microscopes. They are also known as microbes. Some of microbes are harmful, but some of them are useful too- Classification: There are 5 main groups for microbes: a) Bacteria Beruk b) Protozoa Pergi c) Fungi Filipina d) Algae Angkat e) Viruses Vano Characteristics of various type of microorganisms 1. Bacteria Definition: 2nd smallest living things can be seen by electron microscope, have the simplest structure, and have the largest number among the five groups of microbes. Size: Consists only one cell (about 0.5 to 10 micrometer)
Shape:There are four general shapes:a) Cocci Ciumb) Bacili Baboonc) Spirilia Sampaid) Vibrio VietnamStructure:Nutrition:Some bacteria have chlorophyll, so they can make their own food byphotosynthesis process. Some of bacteria don’t have chlorophyll, so they have to be:a) Saprophytes - get food from decaying mattersb) Parasites - get food from other living organismsRespiration:Some of bacteria carry out aerobic respiration, and some of them carry outanaerobic respiration.Reproduction:a) By binary fission
b) By sporesHabitat:Bacteria live in any damp places.2. ProtozoaDefinition:Animals which are made up of only one cell. They are unicellular. Example:amoeba, paramecium and etc.Size:Consists only one cell (about 5 to 250 micrometer)Shape:Have various shapes, but mostly they have irregular shape (no fixed shape)Structure:Nutrition:Some of protozoa live as parasites. E.g: plasmodium. Some of them obtain foodfrom their surroundings. E.g: amoeba and paramecium. Some of protozoa maketheir own food.Respiration:
All of protozoa carry out aerobic respiration Reproduction: a) By binary fission b) By asexual reproduction (spore formation) c) By sexual reproduction (conjugation) Habitat: Protozoa live independently in any ponds, river, damp soils or in other organisms, and they lives in coloniesExercise:1. Name the five main groups of microorganisms2. Bacteria can live in unfavorable conditions. Under such conditions, they…………….3. Label the part of bacteria below4. Size of protozoa is about……………………5. What is the shape of paramecium? ............................
3. FungiDefinition:Plants which do not have chlorophyll. They include mushrooms, moulds and yeast.They do not have root, stems or leavesSize:Some of them are large (i.e mushroom), and some of them are tiny (i.e moulds andyeast)Shape:Have various shapes: i- round ball ii- long filaments iii- oval-shapedStructure:Nutrition:Most of fungi live as parasites (i.e moulds) or saprophytes (i.e mucor) .Respiration:Most of fungi carry out aerobic respirationReproduction:a) By sporesFungi such a mushrooms form spores within their caps. Mucor form sporangium(containing spores). When it ripe, it bursts open and disperses the spore.b) By budding
Habitat:Fungi live in damp dark habitats.Example: Mucor grows on damp stale bread placed in the dark4. AlgaeDefinition:Very simple plants which have chlorophyll. Algae do not have root, stems or leavesSize:Some of them are large (i.e seaweed), and some of them are tiny (i.e diatoms, euglenaand etc)Shape:Have various shapes: i- round ball ii- long filaments iii- oval-shaped iv- network-like structureStructure:Nutrition:Algae possess chlorophyll, so that they can make their own food by photosynthesis.Respiration:Most of fungi carry out aerobic respirationReproduction:a) By asexual reproduction (binary fission)
b) By asexual reproduction (fragmentation)Algae reproduced by breaking a long filament into two.c) By sexual reproduction (conjugation)Habitat:Algae live in fresh water, salt water, damp soil or on damp bark of trees.5. VirusDefinition:Smallest microorganisms and it do not respire, do not excrete waste products, anddo not possess nucleus, cell membrane and cytoplasmSize:About 0.02 – 0.4 micrometer, and can be seen only by electron microscopeShape:Have various shapes, maybe in spherical, rectangular or rod-shapedStructure:
Nutrition: Viruses live as parasites in living cell. Reproduction: Habitat: Viruses live only in living cell.Exercise:1. How do fungi continue its generation under adverse condition?2. Why algae look greenish?3. What a different between algae and tree?4. Which of microorganisms cannot survive outside living cells?A. Bacteria C. VirusesB. Algae D. Protozoa6. State 3 properties of viruses which are not characteristics of living things
FACTOR WHICH AFFECTS TO THE GROWTH OF MICROORGANISMThere are 5 main factors that affect the growth of microorganism:1. NutrientsMicroorganisms need nutrient to live, and they get it by being:a) autotrophicb) saprophyticc) parasitic2. HumidityMicroorganisms need living place with high level of humidity. That means, they needmoisture or water to live, and they will die if they do not get water for a period oftime.However, some bacteria can live in a place without water’s presence by formingspores. For amoeba, they form cyst (spore with outer ring).3. LightMost of virus, fungi and protozoa and some of bacteria prefer dim or dark habitat,while algae and few of bacteria tend to live in bright place since they havechlorophyll to carry out photosynthesis process.4. TemperatureMost suitable temperature for the microorganism’s growth and live is about 37ºC(human’s body temperature).High temperature will kill microorganisms, while low temperature makes theminactive.5. pH valueMost of microorganisms prefer to live in neutral medium (pH = 7)In very acidic (pH = 1 to 3) and very alkaline (pH = 12 to 14) conditions, most ofmicroorganisms will be killed.
USEFUL MICROORGANISMS1. In the Digestion of Food Some bacteria and protozoa help herbivores (e.g: rabbit, goat, cows and etc) and termites digest their food They produce an enzyme called cellulose to help herbivores and termites digest cellulose into glucose enzyme cellulose cellulase glucose2. In Decay 2.1 Formation of humus Some of saprophytic bacteria and fungi decompose organic matter into humus 2.2 Production of biogas and fertilizers Some of saprophytic bacteria decompose organic waste (e.g: waste from oil palm, paddy and coconut) and turn it into methane gas 2.3 Disposal of oil spills Some of bacteria break up oil spills and decompose it into less harmful substance.3. In Medicine 3.1 Antibiotics There are 2 common antibiotics in world, which are: a) Penicillin (prepared from penicillium notatum bacteria) b) Streptomycin (prepared from streptomyces griseus bacteria) Antibiotics can only kill bacteria 3.2 Vaccines Vaccines are prepared from dead or very weak bacteria and viruses. It used to stimulate the body to produce antibodies. Vaccination refers to an injection containing certain vaccines that can prevent a person being infected to a certain disease. Example: BCG injection for dry cough disease.
4. In Agriculture 4.1 Maturing of tobacco leaves Bacteria used to make tobacco leaves mature, so that they can emit desirable smell and taste. 4.2 Nitrogen cycle Nitrogen-fixing bacteria Denitrifying Nitrogen gas bacteria Nitrates Plant and animal proteins Nitrifying bacteria Ammonium compounds Bacteria of decay Figure 4.2- A (Simple nitrogen cycle) 4.3 Productions of chemicals from algae Some algae used to produce beneficial chemicals for human beings. For the example: a) beta-carotene – which has anti cancer properties b) fatty acids – which make cholesterol level in human’s blood become low5. In Industry 5.1 Making breads and cakes Yeast is used in the making breads and cakes. It is mixed with flour, sugar and water; and made into dough Yeast will reacts with sugar to produce alcohol (ethanol), carbon dioxide and energy. By the way, this process is known as fermentation. enzyme yeast + sugar zymase carbon dioxide + ethanol + energy Carbon dioxide released makes the dough rise, so that breads and cakes become very soft.
5.2 Making ethanolYeast is also used to produce alcohol (ethanol) instead of carbon dioxide.5.3 Production of vinegar, and yoghurtVinegar (ethanoic acid) is prepared by using bacteria to change ethanol into ethanoicacid. bacteria ethanol (alcohol) + oxygen ethanoic acid (vinegar) + waterYoghurt (contains lactic acid) is prepared by the action of bacteria on milk. Bacteriawill reacts with lactose in milk and turns it into lactic acid. bacteria lactose lactic acid5.4 Production of soy sauceSoy sauce is produced from the fermentation of a mixture containing mould, yeast,flour and soy beans. Salt is added to make it become salty.Exercise:1. List all factors affect to the growth of microorganism2. Which microorganisms that can live in bright place?3. Tell the range of air humidity which most of microorganisms are very active.4. What is true about microorganisms?A. High temperature will kills microorganisms but low temperature will make them inactiveB. All microorganism grow faster in dry conditionsC. All microorganism cannot produce their own nutrientsD. All microorganism can be seen under light microscope5. In which bacteria cultures in petri dishes A, B, C or D is the highest density of thebacteria colony? Petri dish pH Light Moisture A 3 Bright Moist B 7 Bright Dry C 7 Dark Moist D 10 Dark Dry
HARMFUL EFFECT BY MICROORGANISMS- Microorganisms which can cause disease called pathogens. They can be either bacteriaor viruses or fungi or protozoa.- Before that, disease can be defined as any conditions which actively harm thenormal functioning of the body.1. Diseases Caused by Bacteria METHOD OF DISEASE SYMPTOM TREATMENT/PREVENTION INFECTION1.Tuberculosis 1. Through food 1. Patient loss 1. Can be treated by using antibiotics(Batuk kering) 2. Through infected weight and appetite (i.e streptomycin and isoniazid) air breathed into the for food 2. Can be prevented through lung 2. Patient coughs immunization by BCG vaccine often, and in advanced he coughs out of blood.2. Cholera 1. Through 1. Patient has severe 1. Patient given saline drip and(Taun) contaminated water diarrhoea and antibiotic and food. vomits 2. How to prevent from being infected? 2. Patient feels i - Get vaccine giddy and pain in ii - Boil all drinking water abdomen iii - Cover all food 3. His body iv - Increase the chlorine content in becomes water supply dehydrated.3. Gonorrhoea 1. Through sexual 1. For male, his 1. Can be treated by using antibiotics intercourse testis becomes (i.e penicillin) inflamed and 2. Can be prevented by avoid having enlarged. He feels sex with prostitutes. pain during urination. 2. For female, she has painful vagina and uterus.4. Syphillis 1. Through sexual 1. Patient has fever 1. Can be treated by using antibiotics intercourse and non-itchy rash (i.e penicillin) on the body. 2. Can be prevented by avoid having 2. Patient has sores sex with prostitutes. on the penis or vagina 3. Patient has sore throat and pain in the bones and joint.5. Tooth decay 1. Through food’s 1. Patient feels pain 1. Can be prevented by: waste on the teeth’s for infected teeth I - Having a diet low in sugars surface. since teeth’s pulp is ii - Wash your mouth and brush your badly inflamed teeth after eating. Table 9.4 – A (Diseases Caused by Bacteria)
2. Diseases Caused by Viruses METHOD OF DISEASE SYMPTOM TREATMENT/PREVENTION INFECTION1.Common cold 1. Through 1. Patient gets 1. NO PROPER TREATMENT(Selsema) contaminated air cough, fever, 2. Can be prevented by: (when people running nose and i - having proper diet around sneezes) red or watery eyes ii - have fresh and clean air 2. Patient has a sore iii- keep away from the crowd throat 3. Patient becomes weak2. Dengue fever 1. Through Aedes 1. Patient has high 1. NO PROPER TREATMENT(Demam denggi) mosquito (inject the fever. 2. How to prevent from being infected? virus into patient’s 2. Bleeding in nose i - Keep our living place clean blood) and gums ii - Destroy Aedes mosquito’s habitat 3. Pain in the bones, iii - Fogging joints, muscles and eyes 4. Blue marks appear on the body3. AIDS 1. Through 3 ways: 1. Patient has fever 1. NO PROPER TREATMENT(Acquired i -Sexual and diarrhoea, and 2. Can be prevented by having healthyImmune intercourse coughs very often. clean life.Deficiency ii - Sharing of 2. Patient has lossSydrome) syringes during appetite for food drug addicts and weight. iii- Infected pregnant woman to her baby. Table 9.4 – B (Diseases Caused by Viruses)
Egg are laid singly in stagnant waterAdult mosquito – has black Egg are hatched and becomes larvastripes on the abdomen andlegs Larva grows and becomes pupa Life Cycle of Aedes Mosquito 3. Diseases Caused by Fungi METHOD OF DISEASE SYMPTOM TREATMENT/PREVENTION INFECTION 1.Tinea 1. Through spore of 1. Whitish patches 1. Can be treated by suitable anti-fungal (Panau) the fungus appears on the drugs infected skin 2. Can be prevented by: (usually face or i - keep the body clean and dry back of the body) ii - avoid direct contact with infected person . iii - do not share towel or comb 2. Ringworm 1. Through spore of 1. A reddish area 1. Can be treated by suitable anti-fungal (Kurap) the fungus appears on the drugs infected skin 2. Can be prevented by: 2. Infected skin i - keep the body clean and dry becomes itchy ii - avoid direct contact with infected person . iii - do not share towel or comb Table 9.4 – C (Diseases Caused by Fungi) 4. Diseases Caused by Protozoa METHOD OF DISEASE SYMPTOM TREATMENT/PREVENTION INFECTION 1.Malaria 1. Through 1. Patient has high 1. Can be treated by suitable drugs such (Demam kepialu) Anopheles temperature at as plasmoquine, quinine, or mosquito (inject intervals chloroquine parasitic protozoon 2. After fever, 2. Can be prevented by: plasmodium into patient feels very i - fogging blood) cold and shivers. ii - Keep our living place clean 3. Got rapid pulse rate 4. Got very liitle urine, which is very yellow.
Table 9.4 – D (Diseases Caused by Protozoa)5. The Transmission of Diseases- Diseases transmitted from one person to another by FIVE ways:i- By AirIt occurs when infected person sneezes, coughs or talks. So, a spray or tiny droplets ofmoistures containing pathogens released into airDiseases transmitted by air: common cold and tuberculosisii- By WaterIt occurs when water from ponds, river and sea always contaminated with faeces whichusually contains pathogens. So, these pathogens can spread into water supplies due tounsanitary conditions / seeped through the soilDiseases transmitted by water: cholera and hepatitis Aiii- By FoodIt occurs when food contaminated by pathogens due to unhygienic handling or housefliespresence.Diseases transmitted by food: cholera, food poisoning and hepatitis Aiv- By ContactsIt occurs when there has direct contact between infected people to others or wity objectshandled by infected peopleDiseases transmitted by contacts: tinea, ringworm, AIDS, gonorrhoea and syphilisv- By VectorVectors: Animals carry pathogens in their bodies. For example: Aedes mosquito,houseflies, rats, dogs and etcDiseases transmitted through their bite into human’s blood or carrying pathogen onto thefood.Diseases transmitted by vectors: dengue fever, malaria and cholera
PREVENTION OF DISEASES CAUSED BY MICROORGANISMS1. Prevention through the Control of VectorsCommon vectors, their pathogens and diseases transmitted by them can be shown asfollowing table: Vector Pathogen Disease Aedes mosquito Virus Dengue fever Anopheles mosquito Protozoa (plasmodium) Malaria Housefly Bacteria Cholera Rats Fleas Plague Table 9.6 – A (Vectors and its diseases)1.1 Control of HousefliesTo control houseflies, we must:a) keep our surrounding cleansb) cover our foodsc) throw organic waste into plastic bags and tied it up for disposald) spray insecticides to keep away the adult fly awaye) keep manure and compost heaps far away from houses.1.2 Control of MosquitoesTo control mosquitoes, we must:a) drain marshes and unused pondsb) clean the house from opened empty tins and coconut shellsc) put anti-larva chemicals or into ponds, drains and stagnant waterd) carry out fogging around living placese) fix wire gauze at doors and windowsf) sleep under a mosquito net2. Prevention through SterilizationDefinition of Sterilization:Destruction of pathogens and their spores in a substance or objectType of sterilization:a) heatb) chemicals
c) radiation2.1 Sterilization using Heata) Boiling- Boiling a substance or an object in water for 20 minutes will kill all bacteria cells andmany spores.- Surgical instruments in clinics or hospital are usually sterilized in this way.b) Autoclave- An autoclave is a steam sterilizer. The things to be sterilized are kept in closed containerand steam under high pressure and temperature of 120ºC for 15-20 minutes- All the bacteria and spores will be destroyed in this way.c) Dry air oven- It can be used to sterilize glassware and metal objects.- The things to be sterilized are kept in dry air oven at 170ºC for 15-20 minutes- Effectiveness of sterilization using this way is less compare to using autoclave.2.2 Sterilization using Chemicalsa) Antiseptics- It can be used to prevent the growth of some bacteria and destroy some others.- It usually used for cleaning wounds- Example: iodine solution, hydrogen peroxide solution and potassium manganate (VII)solutionb) Disinfectants- Powerful chemicals to destroy pathogens- It used for sterilizing instruments, containers, cloths, floors, walls and etc.- Example: lysol, formaldehyde, phenol and sodium hypochlorite2.3 Sterilization using Radiationa) UV light- Applied to lamp in surgical operating theatre and lab for air sterilizing.b) Gamma rays- It used for sterilizing surgical instruments and certain foods
- Foods that have been sterilized in this way can be kept for a long period of time and it issafe to eat.3. Prevention through ImmunizationDefinition of Immunization:Process of increasing a person’s resistance to a particular infection by using antibodiesDefinition of Antibodies:- Chemical substance produced from white blood cells to destroy pathogen or neutralizethe toxins produced by pathogen. Each of antibody acts on a particular pathogen.Type of immunity:a) Natural- Refer to situation when a person recovered from an infection, antibodies produced bythe person’s body to fight that infection remains in the person’s blood for months oreven for his/her whole life.- When same infection comes back again, the person has antibody to fight backb) Artificial- Refer to a situation when a person given a vaccination, “injecting a dead or weakpathogens into the person’s body to stimulate his/her body to produce antibody”- Artificial immunity also can be gained when a person is given an injection containsantibody.c) Passive- Part of artificial immunity- Can be done by injecting antibody (usually contains antiserum) directly into a person’sbody- Effect of this immunity is fast but temporary.d) Active- Can be either natural or artificial immunity- Can be done by having antibody after recover from infection or vaccination- Effect of this immunity is slow but permanent.
TREATMENT OF DISEASES CAUSED BY MICROORGANISMS1. Antibiotics2. Antiserum3. Chemotherapy4. Radiotherapy5. Surgery