B8 & B9

• plants are autotrophs so they can make their own food using light,water and carbon dioxide and this is why they are producers in food chains
• photosynthesis is an endothermic reaction in which energy is transferred from the environment when light is absorbed by chlorophyll
• some of the glucose from photosynthesis is converted into insoluble startch for storage.
• the sugars produced by photosynthesis are used to make all substances a plant needs and used in respiration to release energy
• plants and algal cells also need supply of mineral ions e.g. nitrate ions in order to produce protein from glucose. plants absorb nitrate ions from soil and algae absorbs it from water
• venus flytrap obtains most of its nutrients from animals that it catches and digests and the plant obtains nitrates by digesting animal protein
• Most photosynthesis takes place in specialised mesophyll cells which are packed with chloroplasts to absorb as much light energy as possible
• Glucose is stored as insoluble starch so that it doesn't affect water balance of plant. High concs of dissolved glucose would affect way water moves by osmosis
• Hydroponics is where plants are grown in solution of mineral ions instead of soil so that they never run out of essential ions
• The more a plant photosynthesises, the more biomass it makes and faster it grows
• Aerobic respiration takes place continously in plant and animal cells
• Aerobic respiration is an exothermic reaction using glucose and oxygen to transfer energy and the energy transferred is needed for all living processes
• In aerobic respiration, carbon dioxide and water are produced as waste products
• Most of chemical reactions of aerobic respiration take place in mitochondria and are controlled by enzymes
• Investigations involving aerobic respiration use limewater to detect carbon dioxide which turns cloudy white and there may be rise in temp
• When you exercise, you muscles need more energy so they can contract. this means you need to increase rate at which oxygen and glucose reach muscle cells for aerobic respiration. you also need to remove waste carbon dioxide more quickly
• When you exercise, breathing rate increases and you breathe more deeply. the rate at which oxygen is brought into your red blood cells is increased and this is delivered to your respiring muscle cells. it also means carbon dioxide can breathed out more quickly
• When you exercise, your heart rate increases and arteries supplying blood to your muscles dilate. this increases amount of oxygenated blood flowing to muscles which increases supply of oxygen and glucose to muscles, increasing rate of cellular respiration
• When you exercise, glycogen stored in muscles is converted into glucose needed for respiration and is supplied to cell so more energy can be released during exercise
• if you use your muscles over long period, they will become fatigued and stop contracting efficiently. when you exercise hard your heart may not be able to pump oxygenated blood to respiring cells quickly enough to carry out aerobic respiration so muscles dont get enough oxygen and start to respire anerobically
• In anaerobic respiration, glucose is not completely broken down and lactic acid is produced
• in anaerobic respiration, less energy is transferred from glucose as it isn't fully broken down
• Oxygen debt is when exercise has been done, lactic acid produced must be completely broken down to carbon dioxide and water so you need to take in extra oxygen for a while after you stop exercising
• Plants and yeast cells anaerobic respiration produces ethanol and carbon dioxide
• Anaerobic respiration in yeast cells is called fermentation
• In liver process of deamination takes place where amino group is removed from amino acid produce ammonia which is converted into urea which passes into blood to kidneys and is excreted in urine
• In liver, poisonous substances like ethanol are detoxified. the breakdown products are transported in blood to kidneys so they can be excreted in urine
• old red bloods are broken down in liver and iron is stored to make new red blood cells
• in liver, lactic acid is converted to glucose once oxygen debt has been repad then it is completely broken down to carbon dioxide and water