27/05/13Plant cells vs. Animal cellsPlant cells vs. Animal cellsBoth types of cell have these: Only plant cellshave these:NucleusCytoplasmCell wallLargevacuoleCellmembrane1)2)3)6)7)Mitochondria – Energy isreleased here by respiration4)Chloroplasts
27/05/13Specialised cellsSpecialised cellsConsider the root hair cell in plants:It was “suited” to its job of taking inwater and nutrients in 2 ways:1) It had a large surface area2) It had a thin cell membraneThe sperm cell is an example of aspecialised ANIMAL cell:Strong tail forswimmingVacuole containingenzymes
27/05/13Cells, tissues, organs and systemsCells, tissues, organs and systemsBasically, all living things aremade up of cells…A group of CELLS makes up aTISSUEA group of TISSUES makes upan ORGANA group of ORGANS makes up aSYSTEMA group of SYSTEMS make up anORGANISM
27/05/13Some systems in the human bodySome systems in the human bodyMuscular system Skeletal systemCirculatorysystemRespiratory systemDigestivesystem
27/05/13DiffusionDiffusionDiffusion is when something travels from an area of highconcentration to an area of low concentration. For example,consider the scent from a hamburger…The “scent particles” fromthis hamburger are in highconcentration here:Eventually they will“diffuse” out into this areaof low concentration:
27/05/13DiffusionDiffusionCells use diffusion to swapthe oxygen they need forthe carbon dioxide theyno longer want:Other examples of where diffusion happens in humans:Alveoli in the lungs Villi in the intestinesOxygendiffuses inOut goeswaste CO2
27/05/13The digestive systemThe digestive systemThe whole point of digestion is to break down our food sothat we can get the bits we need from it…The main foodsaffected areCARBOHYDRATES –these are broken downinto GLUCOSEPROTEINS – these arebroken down into aminoacidsFATS (LIPIDS) –These are broken downinto fatty acids andglycerol
27/05/13The small intestineThe small intestineThis is where the “small parts” are absorbed into our bloodstream…Glucose getsabsorbed intothe bloodEverything elsepasses into thelarge intestine
27/05/13EnzymesEnzymesEnzymes are chemicals produced by the body to help_______. When they react with food they break it downinto ______ pieces which can then pass into the ______:Carbohydrase (produced in the mouth,pancreas and small intestine) breaks_______ (a carbohydrate) down intoglucose:Protease (produced in the stomach,pancreas and small intestine) breaks_______ down into amino acids:Lipase (produced in the pancreas andsmall intestine) breaks fats (_____)down into fatty acids and glycerol:Words – blood, lipids, proteins, digestion, starch, smallerBloodstream
27/05/13The Model IntestineThe Model IntestineMethod:1) Put some water into two boiling tubes and test the water for starch andglucose2) Place the starch into the visking tube bag, add some enzyme and wash theoutside3) Place some starch WITHOUT enzyme in another visking tube bag4) Place both visking tubes into the separate boiling tubes and start the stopclock5) Test the water around the visking tubes for starch and glucose every twominutes6) After ten minutes test the water one last time and then test the solutions inthe visking tube bag1) Why did the starch stay inside the visking tube?2) What difference did adding the enzyme make? What did it do tothe starch?3) Where did the glucose go?
27/05/13Bile and the liverBile and the liverBile is a chemical produced in theliver and stored in the gallbladder. It has 2 functions:1) It neutralises stomach acidand produces alkalineconditions for enzymes towork in2) It emulsifies (“breaks down”fats:FatglobulesFatdroplets
27/05/13The Respiratory SystemThe Respiratory SystemRibs – to protectthe chestBronchiolesBronchi Trachea – has stiffrings of cartilage toprevent it collapsingRib muscles –to raise andlower the ribsLungDiaphragm –muscularsheetAlveoli (“air sacs”)– gas exchangetakes place here
27/05/13Gas exchangeGas exchangeAlveoli are very good at exchanging gases because…1) They have a LARGE surface area2) They have a good blood supply3) They are moist
27/05/13(Aerobic) Respiration(Aerobic) RespirationWords – breathing, energy, Mrs Gren, respiration, foodA while ago we learnt about ___ ______. Each of theselife processes needs ENERGY. ___________ is theprocess our bodies use to produce this energy:Glucose + oxygen water + carbon dioxide + ENERGYThe glucose we need comes from ______ and the oxygenfrom _________. Water and carbon dioxide are breathedout. The MAIN product of this equation is _________.
27/05/13Anaerobic respirationAnaerobic respirationUnlike aerobic respiration, anaerobic respiration is whenenergy is provided WITHOUT needing _________:This happens when the body can’t provide oxygen quick enoughfor __________ respiration to take place.Anaerobic respiration produces energy much _______ thanaerobic respiration but only produces 1/20thas much.Lactic acid is also produced, and this can build up in musclescausing ______ and an oxygen ______.This “debt” then needs to be “repaid” by deep breathing to________ the lactic acid.Words – debt, oxygen, fatigue, oxidise, aerobic, quickerGlucose lactic acid + a bit of energy
27/05/13Aerobic vs. anaerobic respirationAerobic vs. anaerobic respirationSimilaritiesDifferences
27/05/13The Circulatory systemThe Circulatory systemThe circulatory system is responsiblefor pumping ______ around the body.We need blood to be taken around thebody because blood contains ________and _______. These are needed sothat all the ____ in our bodies canproduce _____ through _________.The main organs in the circulatorysystem are the _____, the lungs andthe kidneys.Words – energy, heart, blood, glucose,respiration, oxygen, cells
27/05/13The “Double Circulatory” SystemThe “Double Circulatory” System1. Deoxygenatedblood is pumpedfrom the heart tothe lungs3. The oxygenatedblood is thenpumped to the restof the body2. The bloodreceives oxygenand is pumped backto the heart4. The oxygenleaves the blood tobe used forrespiration in thebody and the bloodgoes back to theheart
27/05/13The HeartThe Heart1. Deoxygenatedblood (i.e. bloodwithout oxygen)enters through thevena cava into theright atrium2. It’s thenpumped throughthe tricuspid valveinto the rightventricle3. It’s then pumpedthrough the semi-lunarvalve up to the lungsthrough the pulmonaryartery4. Oxygenatedblood from thelungs entersthrough thepulmonary vein intothe left atrium5. It’s then pumpedthrough thebicuspid valve intothe left ventricle6. It’s then pumpedout of the aorta tothe rest of thebody
27/05/13Arteries, veins and capillariesArteries, veins and capillariesArteries carry high pressureblood away from the heart.They have smaller lumen andno valves.Veins carry low pressure blood back to theheart. They have thinner, less elastic walls andhave valves to prevent backflow of blood.Capillaries have thin walls(one cell thick) to allowglucose and oxygen to passthrough. Also used toconnect arteries to veins.“Lumen”
27/05/13The four parts of bloodThe four parts of blood1. RED BLOOD CELLS – contain haemoglobinand carry ______ around the body. Theyhave no _______ and a large surface area.2. PLATELETS – small bits of cells that liearound waiting for a cut to happen so thatthey can ____ (for a scab).3. WHITE BLOOD CELLS – kill invading_______ by producing _________ orengulfing (“eating”) the microbe.These three are all carried around by thePLASMA (a straw-coloured liquid). Plasmatransports CO2 and ______ as well as takingaway waste products to the ______.Words – antibodies, clot, kidneys,oxygen, nucleus, glucose, microbes.
27/05/13MicrobesMicrobesMicrobes are micro organisms that can cause diseases. Theycan enter the body in a number of ways:…or othernaturalopenings…They can bebreathed inthrough themouth or noseThey can enterthrough cuts orbites in the skin
27/05/13DiseaseDiseaseA disease is any condition where the body isn’t working as it should. Thiscould be caused by a malfunction in the body (as with diabetes), or it couldbe caused by the two types of MICROBE:VirusesBacteria•1/1000thmm big•Living cells (some are harmless)•Grow very quickly•Affected by antibiotics•Examples: food poisoning,tetanus, sore throats•1/1,000,000thmm big•Genetic info inside a protein coat•Not affected by antibiotics•Release poisons•Examples: colds, flu, polio,chicken pox
27/05/13Microbes: our defence against themMicrobes: our defence against themOur bodies have four major defence mechanisms againstinvading microbes:If our skin iscut plateletsseal the woundby clottingThe breathingorgans producemucus to cover thelining of theseorgans and trap themicrobesThe skin actsas a barrierOur blood containswhite blood cells
27/05/13Fighting diseaseFighting diseaseIf microbes enter our body they need to beneutralised or killed. This is done byWHITE BLOOD CELLS:White blood cells do 3 things:1) They eat the microbe2) They produce antibodies toneutralise the microbe3) The produce antitoxins toneutralise the poisons producedby microbes
27/05/13Producing antibodiesProducing antibodiesStep 1: The white blood cell “sees”the antigen (microbe)Step 2: The cell producesantibodies to “fit” the antigenStep 3: The antibodies fit onto theantigens and cause them to “clump”Step 4: The antigens are “eaten”by the white blood cellsYou’re goingdown
27/05/13Fighting diseaseFighting diseaseNATURAL IMMUNITYThis is when antibodies are produced by aperson when needed or they are passed on bythe mother during pregnancy.ARTIFICIAL IMMUNITYCan be done in two ways:1) A vaccine with dead microbes is injected– the body is “tricked” into producingantibodies ready for the real thing. Thisis called PASSIVE IMMUNISATION2) The antibodies are injected directly intothe body – this is called ACTIVEIMMUNISATION.