The Circulatory System: The Intestine VILLI= tiny protrusions in the intestine which help to absorb the products of digestion Use active transport + diffusion to gain as much of the valuable materials, especially sugar, as possible Villi help increase absorption because they: Have a large surface area (squashed up) Are moist Are very close to a large network of capillaries (absorbed straight into blood stream) Active Transport Human Kidney Vital for homeostasis Works by filtering everything from blood and then reabsorbing all the sugar, as well as the mineral ions and water needed. Active transport ensures ALL sugar is reabsorbed and diffusion makes sure mineral ions and water is reabsorbed in the right amounts Hot day with little water intake = little urine (concentrated) Cold day with large water intake = lots of urine (dilute) Active Transport- requires energy to transport molecules from low to a high concentration B3) Biology Dialysis Transplant Much more readily available Enables you to lead relatively normal life No risk of rejection No need for medicine Eat what you like Lead a normal life Free from restrictions which come with regular dialysis sessions Transpiration is the loss of water by evaporation from plants. Plants lose water when they open the stomata in the leaves to let in carbon dioxide. Transpiration happens faster in hot, dry, windy conditions. Keywords: Active Transport, Osmosis, Diffusion, lungs, alveoli, villi, stomata, root hair cell The Breathing System: -Takes air into and out of your body. -O2 diffuses into your bloodstream and CO2 diffuses out. -Alveoli=large surface area, moist, thin walls. The Circulatory System: -The body transport system consists of blood vessels, the heart and blood. -Human beings have a double circulation. -the heart works a s a pump moving blood around the body. -the 3 main types of blood vessel are the Arteries (Away from heart), veINs (INto heart) and capillaries. The Blood WHITE BLOOD CELLS- fights PLATELETS- help blood to clot PLASMA- holds dissolved substances, glucose (taken from the small intestine to the body organs), CO2, waste products (urea from the kidneys) RED BLOOD CELLS- No nucleus- more room for Haemoglobin Special shape with a lowered Centre- greater surface area to absorb gas HAEMOGLOBIN- substance which gains oxygen from the lungs to form OXYhaemoglobin. Then releases oxygen into cells. body’s cells lungs Keywords: Transpiration, artery, vein, capillary, heart, red blood cells, haemoglobin, plasma, platelets, an/aerobic respiration,

Growing Microorganisms Micro-organisms grow in an agar culture medium with a carbohydrate energy source and various other vitamins, minerals and proteins You need to take careful safety measures and use sterilized equipment to ensure the growth of uncontaminated cultures Theory of Biogenesis Pasteur did a series of experiments. MICROBES CAUSE THINGS TO DECAY THIS MEANS THAT LIFE (MICROBES) CANT JUST APPEAR FROM NOTHING, (SPONTANEOUS GENERATION). Exchange in Plants Need osmosis in roots (for water) and diffusion near stomata (for CO2) Leaves thin + flat to increase SA for light and a waxy cuticle to prevent evaporation Root hair cells increase SA because of long, thin hairs Most minerals + ions needed taken through roots Fermenters Microbes can be grown on a large scale using fermenters Fermenters have features such as an oxgen supply, stirrer to keep microorganisms in suspension and maintain an even temp, water-cooler jacket to remove excess heat and measuring instruments such as pH and temperature gauges Mycoprotein is produced by allowing the fungus ‘Fusarium’ to grow on sugar syrup in aerobic conditions Biogas – mainly methane – produced by anaerobic fermentation of a wide range of plants and waste materials that contain carbohydrates Gets rid of waste, solves energy needs and is renewable, however hard to do it on a large scale Bacteria and Food production Bacteria are used to make cheese and yoghurt Yoghurt is formed when bacteria act on lactose (sugar in the milk), producing lactic acid and changing the texture and taste of the milk Different type of bacteria is added for cheese, making much more lactic acid is made and it is thicker (curds) This is cooled and left in moulds to set and then more bacteria is added to give different flavours Antibiotics kill bacteria Penicillin Discovery of penicillin was made by Alexander Fleming. Penicillium mould is used as it provides more penicillin, as it is made in a fermenter. Keywords: Biogas, biofuels, Biogenesis, Pasteur, mycoprotein, antibiotics, Flemming Yeast and Food production Yeast is a single celled organism which can respire both aerobically and an anaerobically Aerobic respiration produces CO2 and water and is used to make bread rise Anaerobic respiration produces CO2 and ethanol, the process is known as fermentation This is used in the production of beer, wine and other alcoholic drinks Effect of Exercise Energy from respiration used to make muscles contract When this happens, you need more respiration to take place (ie more O2 + glucose, quicker CO2 release) Causes increased heart/breathing rate Arteries dilate  more blood for muscles increases oxygen/glucose supply CO2 is removed quicker Anaerobic Respiration Your everyday muscle movements are made possible by AEROBIC respiration If heart rate is increased, blood cant supply O2 quick enough Anaerobic respiration doesn’t involve O2 and is less efficient Glucose  Lactic Acid (+ energy) Lactic acid needs to be got rid of (by reacting with O2 to form CO2 + water) = OXYGEN DEBT Biofuels Ethanol based fuels can be produced from anaerobic fermentation of sugar cane juices by the enzyme carbohydrase. +ves = does’nt produce toxic gases, much cleaner and can be mixed with petrol, carbon neutral -ves = needs lots of space, poor countries grow cash crops instead of feeding people  starvation. BREATHING CELLULAR RESPIRATION Muscle cells carrying out Keywords: kidney, dialysis, transplant, immunosuppressant drugs, microbes, fermentation, yeast, bread, alcohol, bacteria, yoghurt lactic acid,