Osmosis:Osmosistakes place when two solutions are separated by a semi permeable membrane. Asemi permeable membraneis a membrane which allows some things to pass through themembrane such as water, but blocks others through its pores. The bigger molecules cant get through the pores, e.g sugar. It acts as a barrier on the exterior of a cell, and is also referred to as apartially permeable membrane. This is down the concentration gradient, from the dilute solution to the concentrated. The water particles move across the membrane repeatedly until there is an even concentration of water molecules on both sides. Osmosis occurs in things like red blood cells, and is basically likediffusion in water.Red blood cells hold substances such as oxygen, if you were to place a red blood cell in a dilute solution. Water would move in, the membrane would not be able to stand high pressure and the cell would burst. If you put it in a concentrated solution, water would move out and the red blood cell would shrink. This is important as the plasmid in the blood must be at the right concentration. If a cell uses up too much water then the concentration can be too high, osmosis will return the balance. Osmosis is extremely important for maintaining internal conditions.We can have plant cells that we put in a concentrated solution. Water will move out, this will not collapse due to the cell wall but the cell will shrink. When the plant cell is ina dilute solution then the cell will take in the water molecules and becometurgid.

Active Transport:Active transport uses energy to move substances up a concentration gradient, or more commonly across a partially permeable membrane. In active transporta special transport protein in the cell membrane picks up the useful particle on one side of the membrane. There are loads of proteins embedded in the cells lipid bilayer (a film two molecules thick, formed by lipids [fats]). These proteins are very important in active transport, because they do most of the work.They are positioned to cross the membrane so one part is on the inside of the cell and one part is on the outside. Only when they cross the bilayer(a film two molecules thick, formed by fats) arethey able to movemolecules and ions in and out of the cell.This normally uses energy from cellular respiration. With a higher rate of respiration theres a higher rate of active transport.Active transport is widely used in cells, for example the mineral ions in soil can be absorbed by active transport, even though its against a concentration gradient.

Sports Drinks:When you exercise you release energy by respiration (contacting muscles) and use up sugar. You also sweat to maintain the temperature ofyour body. The more you sweat the more mineral and water ions you lose, which can affect the concentration of your body fluids as if the body fluids become concentrated, water will leave your cells and become dehydrated. To exercise optimally you have to replace these ions, which sport drink companies claim to do.Sports drinks are mainly water, sugar (glucose) and have more mineral ions than soft drinks. Evidence suggests that for normal levels of exercise water is at least as effective as a sports drink.

Exchanging Materials:Exchange surfaces are more effective with a larger surface area, are thin so that they have a short diffusion path, efficient blood supply (for animals) and are well ventilated (for animals).In the lungs the alveolus has the job ofcarrying out the exchange of co2 and oxygen with the air. It has a large surface area due to the air sacs. They also have a rich blood supply which maintains a concentration gradient in both directions. The concentration gradient is also quite steep, for efficient diffusion.In the small intestine there are villi, which are designed to increase the surface area of the small intestine in order to absorb the most digested food possible.

Ventilating the lungs:The lungs are found in the thorax and areprotected by your ribcage and is separated from your digestive system by your diaphragm. In order to ventilate the lungs we need to change the shape & volume of the lungs.The intercostal muscles in between the rib cage contracts which causes the rib cageto move upwards and outwards. Diaphragm also contracts which causes the diaphragm to become flatter. This draws the bottom of the lungs downwards, which causes a higher volume inside the lungs. This means that theres a lower air pressure inside the lungs. Theres a higher pressure on the inside, which means the air is drawn into the lungs (diffusion). The opposite happens for the air to move out. The intercostal muscles relaxes this causes the ribs to go downwards and inwards. The diaphragm relaxes, thatcauses a decreased volume in the lungs which increases the air pressure inside the lungs which causes air to move out.

Artifical Breathing Aids:Negative pressure ventilators work by placing an airtight machine from the neck down. Then a vacuum is createdaround the thorax, which creates a negative pressure, hence the name Negative Pressure Ventilator. The negative pressure leads to the expansion of the thorax and a decrease in pressure. The result of this is that air is drawn into the lungs, as when thevacuum is released the diaphragm and chest well cause exhalation. This method was developed in the 1920s, to help with polio and it successfully did over the years. There are two disadvantages though, one is that the patient is confined to the machine, hence it cannot be a long-term support system. The second is that the vacuum on full body machines can affect the abdomen, which leads to blood pooling up in lower parts of the body, which again doesnt allow it to be a long term treatment.I think that thisis a good idea and treatment for polio sufferers, however not for long-term scenarios or for over-usage as it can affect the abdomen.Positive pressure ventilators is when air is forced into the lungs through a tube (which is inserted into the trachea). The ventilator will pump air into the tubes, which would cause the lungs to inflate. When the ventilator stops, then the diaphragm and chest wall cause exhalation. The method does seem quite simple, and has been used a lot since the 1950s, however it does have its bad side and good side. For example, its used in operations when doctors need access to the body. This is important, otherwise some major surgeries wouldnt be conducted. On the other hand for long term ventilation, the tube would have to be inserted in the back of the neck, but at least theres an option for long term ventilation. The only negative I can realistically see for this is that the body may become dependent on the system, and it wont allow full recovery but it is like a life support.Therefore, I conclude that positive pressure ventilations are better.

Exchange systems in plants:CO2is diffused into the leaf through the underside of the plant through the stomata, this is required for photosynthesis. The bi-product is oxygen which shows the exchange system.Water is also an exchange system, which goes in through the roots (osmosis). In the water we have mineral ions, potassium, nitrates and magnesium are examples of mineral ions. The roots become efficient in an exchange system due totheir large surface area (root hair cells).Leaf is very flat & thin which can shorten the diffusion path, substances can be released & absorbed quicker. The cells in a leaf are arranged in a specific way to aid exchange systems.Guard cells can open and close to allow gases in and out.Mesophyll cells are loosely packed, a lot of different surfaces that can absorb gases.

Transpiration & Water Loss:Water is very important for photosynthesis.A certain proportion of water (usually from the underside ofthe leaf) evaporates from the leaf. This process is called transpiration.Transpiration can vary on the type of environment, more heat would increase the rate. Dry weather (low humidity/water particles in the air) this causes a higher concentrationgradient and transpiration rate would be faster. With wind particles would move away and rate would increase.These conditions may cause the plant to wilt if theres not enough water supply.Guard cells will open and close the stomata if these conditionsare present or if theres a low supply of CO2. This reduces the amount of water that is lost via transpiration.Cobalt chloride paper: In the presence of moisture it turns pink (this means that water is evaporated). You would use this in an experiment in order to determine different water evaporation times in various conditions (speed of paper turning pink).

The heart and circulation:1) The main job of the heart is to pump blood (transports everything) around the body.Theres a lot of muscle in the walls of the heart, important due to constant pumping of the heart. Coronary arteries supply the blood that we require for the heart. This blood contains the sugar and oxygen that give heart the fuel to keep on pumping. If theres a problem with the coronary arteries then theres a high risk of heart attack.Heart diseases cause a blocked coronary artery (cholesterol could block it). A STENT could help this, you would insert it into the artery which would cause it to widen. This would allow the blood flow to return to normal.How the heart pumps blood:Blood comes from two parts of the body, the atria fills up

The atria contracts and forces blood into the ventricle

The ventricles will fill up

The ventricles will contract and the blood will flow out

The valvesmake sure the blood flows in the right direction (like a one-way door).

http://www.bbc.co.uk/bitesize/intermediate2/biology/images/200/184_bitesize_intermediate2_biology_subunit1_2_heartstructure.pngBlue side or Vena Cava side represents deoxygenated blood.PulmonaryArteryhas thick walls, layer ofmuscleand layer ofelastic tissue. The oxygenated blood has a lot of pressure due to it having more components. Its also roundish in shape.Pulmonary Vein has thinner walls and its not as round in shape due to the squashability because of less muscle & elastic tissue.Capillaries are narrow blood vessels so that they can penetratedeep into the tissue in order to get close to the cells. Arteries branch off into capillaries. Capillaries can only take 1 blood cell at a time.

The Blood:75% of the blood is plasma, a yellow liquid that has the job of transporting carbon dioxide fromorgans to the lungs. The lung scan breathe the Co2out. It also transfers the soluble products of digestion, these are also transported to organs.Red blood cells are cells that are in the blood, job is to transport oxygen. Manufactured in bone marrow no by mitosis. Haemoglobin is stored into the rbc, no nucleus to allow more space for haemoglobin. The special disk like shape maximises surface area. Haemoglobin carries oxygen, once it is exposed to a high concentration of oxygen it becomes oxyhaemoglobin.When it goes around to cells in the body it splits up to oxygen + haemoglobin and oxygen is given to the cells (for respiration). Where theres a low concentration of oxygen, itll give it to that tissue.White blood cells have an important role in defending the body against micro-organisms.Platelets are fragments of cells, they are also suspended in the blood. They allow the blood to clot when there is a cut, this will block up the wound (scab) and allow it to heal. They also have no nucleus and arent technically cells.Urea is produced in the liver and is made from extra amino acids that the body has. This is transported in the plasma to the kidneys, then theyll filter out the urea and this will be disposed through the urine.Artificial Blood & Hearts:Blood:In real blood we have many components, plasma, rbcs, wbcs and platelets. The main purpose of the blood is to transport oxygen which it does with red blood cells.During surgeries when theres a high blood loss, we require artificial blood. We cant use real blood due to lack of donors, risk of infection, shelf life issues (donor blood can be stored from 42 days max.) and compatibility (blood type). Artificial blood can also be used immediately.However, there have been clinical trials that saytheres an increased risk of heart attacks. Some types also have side effects and insoluble.Hearts:A transplant is the best solution however they have a lack of donors (lack of availability). Artificial hearts can extend life span, however there is an extremely low success rate. There is a risk of infection, risk of clotting (rough surface seems like injury > will cause platelets to clot), battery needs to be recharged/changed and discomfort to the patient. This can be used until a donor is found.

Transport in Plants:The phloem are living cells that are tube shaped. They allow sugars (that are made from photosynthesis) to travel up and down.The xylem are made from dead cells and have the job of transporting minerals and water. Water is important forphotosynthesis, it also helps to keep a cell turgid and upright.Root >Xylem > Leaf (Transpiration stream)

Recommended Investigations:You can put celery into water with red food colouring. A little while later you can cut it into pieces, you can see red dots. This is where the xylem is located and the path waters taken up.

The potometer is a method of measuring the rate of which water evaporates from the leaf (transpiration rate). It is used to measure the movement of air bubbles. This gives an indication of how quickly water evaporates from a leaf. You can also changeconditions to determine how factors affect the rate of transpiration.

Homeostasis:Homeostasis is the controlling of substance levels or getting rid of waste products. We need get rid of CO2, also we breathe out excess water vapour (can do this through urine). CO2comes through respiration (glucose + oxygen = energy + carbon dioxide + water). Transported to the lungs via the blood and then is breathed out. Some of this can also be lost through sweat.Excess amino acids can be converted into urea (this happens in the liver). That urea is then transported into the kidneys via the blood.First the blood is filtered, urea, sugar, glucose, mineral ions etc go through the kidney tubule. Some proteins are too large to go through the tubule. All of the glucose is returned back into the bloody along with the required mineral ions, and required water however none of the urea is transported back. This is calledselective reabsorption.

Kidney Dialysis and Transplants:Dialysis:Kidneys have a role in removing urea, excess ions and water. If the kidney doesnt work the urea and excess ions can build up in the body, over a long period of time it can cause death.In order to filter the blood for someonewhose kidney doesnt work we need a dialysis machine. The blood that is leaving the person goes through some tubes, to a dialysis machine. In the machine there is a special fluid called dialysis fluid that helps to filter the blood. There is also a bubble trap, acid drips through any bubbles with diminish them.Blood goes in through one way, dialysis fluid goes in through the other way. The membrane that separates the blood from the fluid is a partially permeable membrane, proteins and red blood cells cant pass through.Substances such as urea will diffuse out of the blood, high concentration on the inside (low on outside) therefore itll diffuse out.We require the same amount (concentration) of sugar on the inside and outside so that theres no net movement.The ideal ion concentration will be kept on the inside and out to allow no net movement.Pros:-Regularly available-Dont have to take drugs everydayCons:-Have to take regular, long sessions every week-Less freedom, have to be close to the machine-Be careful about your diet in between sessionsKidney Transplant: Involves in adding another kidney in another cavity of the body (if its not infected). If the kidney is from another person it will have a different tissue type. This means that the immune system (antibodies) may attack the tissue.We need to minimise this by finding a reasonable tissue match.Pros:-Dont need to control your dietCons:-Finding a donor-Rejection of the kidneys tissue type-You need to take immunosuppressant drugs, might make you prone to illness due to the weakening effect of these drugsTemperature Control:Inside the brain there is a thermoregulatory centre, this has temperature receptors which detect temperature of blood that flows from the body to the thermoregulatory centre. Its also responsible for controlling temperature in the body.In the skin you have receptors which send nerve impulses to the thermoregulatory centre.When the body gets too hot, the body starts to sweat. This cools down the body as the water in the sweat will evaporate away and carry away the heat energy from the surface. However, water is lost from the body and needs to be replacedand the water level needs to be balanced. Another response is that there will be less urine produced.The core body temperature is the inner temperature which any fluctuation in temperature. When the core temperature goes too high or too low it could be life threatening.When the body wants to lose heat, blood vessels (arterioles) which supply the skin capillaries dilate. More blood flows through the capillaries causing more heat to be lost by radiation. This is why the skin looks red when a person is feeling hot, more blood flowing at the surface of the skin.You have a sweat gland that produces sweat when its too warm. Sweat glands releases more sweat. The water in the sweat evaporates carrying the heat energy away. This cools the skin surface and body.When its cold the blood vessels constrict (go narrower). Therefore less blood flowing through skin capillaries and the less radiation of heat. Muscles may also shiver, muscle contraction requires energy. Process of respiration produces some heat energy. Carries on until the body is at a suitable temperature.Control of Blood Glucose:Glucose is needed to provide energy from body, the process that releases energy from glucose is called respiration.If the blood sugar levels go to high you might need to get to the toilet, thirst, hunger, blurred vision, dizziness and nausea. If you have blood sugar that is too low you have hunger, weakness, inability to concentrate, dizziness, loss of conscious.The pancreas produces insulin that controls glucose levels. It secretes insulin into the blood if you have higher levels of glucose. This allows the glucose to enter the cells and get out of the blood. It also converts glucose into glycogen. Glycogen is a long chain of glucose molecules.When the glucose levels go low, less insulin will be secreted into the blood. Insulin is a protein and hormone. This can happen with minimal intake of food or excess exercise. Another hormone called glucagon is released from the pancreas and has the job of converting glycogen into individual glucose units. Converting happens in the liver. This will cause a rise in glucose levels.If the body cant control glucose the levels will go higher and higher, then start to go down after a long period of time. This can occur in Type 1 diabetes. In type 1 diabetes the pancreas makes no or little insulin. Therefore glucose cant enter the cells, and cant be converted into glycogen in the liver for storage. This will lead to high levels of glucose remaining in the blood.This can be controlled by taking insulin injections, before meal times. This would help to replace the natural insulin secretion in the body. Diet and exercise helps too, exercise helps to respire the glucose.Human population growth:Acid Rain:-Burning fossil fuels-Causes the emission of sulphur dioxide (SO2)-Dissolves in rain water-Causes acid rainWe require more land for building, quarrying (limestone), need for dumping waste, and using land for farming. This reduces the biodiversity of the environment.

Deforestation:
Deforestation is the cutting down of trees and vegetation in large amounts. When we cut down trees we reduce the amount of CO2taken down in the atmosphere which can have an effect on global warming. As wood is burnt the locked away Co2is released and let out.Biodiversity is the range of species living in the environment. Deforestation reduces biodiversity.The reason behind deforestation is to create land for farming or creating crops for biofuel (ethanol).Methane comes from rice, when rice is growing then methane is produced. Cows have a digestive process which produces methane, they have to fart it out. This also happens with sheep.Peat bogs are areas that are marshy. They contained party decayed plant material, you can use it to increase the soil quality or burn it for soil. This releases CO2.Global Warming may cause:-Increase in sea levels (melting of ice caps)-Change in climate-Change in species distribution > Disrupts food chains-Change in migration patterns (birds)CO2is sequestered (carbon sinks).Biogas:Generating a fuel that can be used in many ways, more environmentally friendly. You require a biogas generator in order to produce biogas. You can put waste material in order to grow bacteria, e.g animal waste, waste foods, waste plants, human waste. This goes in a biogas generator which produces slurry (waste material being broken down). Its important that you have anaerobic conditions (no oxygen) and its at a warm temperature in order to produce a certain type of gas. This produces the biogas (mixture of gases). The tank is made so that no air can get in and when biogas is created the high pressure causes it to be automatically removed.The main component of biogas is methane, theres also water vapour, hydrogen, hydrogen sulfide. Once the slurry is broken down it can be used as a fertiliser, it is carbon neutral and environmentally friendly.We require a temperature around 30 degrees due to the enzymes. In countries where its a little colder the tanks are underground in order to provide a layer of insulation.The volume of CO2may be higher initially due to aerobic respiration, then anaerobic respiration takes place. The carbon dioxide level then goes down.Can be used for cooking, heating and electric production.Food Production:Animals or plants are the main sources of vegetation. E.g. Chickens will use the energy in the grain forgrowth,movement and heat. Not all biomass is passed on due to it being lost.The biomass is lost due to more steps, a vegetarian has a more efficient food chain. We need to reduce the heat produced, movement in order to make the food chain more efficient.Factory farmingis when we have certain conditions that these animals are bred in, these restrict movement, keeping them in a small and confined area, and keep the place warm.Fish Farming:The numbers of fish that are edible to humans are reducing drastically.-Smaller net sizes-Quotas (limits the number youre able to fish)-Avoiding fishing during mating season-Avoiding breeding grounds-Mesh sizes (small fish can escape the net)This will maintain the fish stocks in the oceanProblems are that its hard to check and control if these things are taking place.Mycoprotein:Source of food that comes from fungus which is very high in protein and very low in fat. The fungus is calledfusariumand is grown in aerobic conditions. The air goes into the fermentation vessel, bubbles through the mixture and that provides the oxygen. There is a filter to prevent bacteria from getting in which could contaminate the fusarium. The air is filtered too. The air also has the job for distributing the heat and mixing all of the components. Glucose syrup and minerals help growth.Aerobic respiration can produce CO2which escapes from the top.Aerobic respiration produces a lot of heat, if it goes higher than 35/37degrees the growth could slow down.This is why there is a cooling water jacket that keeps the fermentation vessel cool. Cool water goes in to surround the main part that fermentation is working, there is a constant stream of cool water that keeps conditions cool.In between growing the fusarium we filter the air, sterilise with steam and sterilise the mycoprotein.Food Production Evaluation:Food Miles is transported food.Another pro of factory farming are more efficient food chains.