gcse biology- bioenergetics p1

making glucose and oxygen from water and light and co2

carbon dioxide + water ----(light)---- glucose + oxygen

6CO2+6H2O ----(light)--- C6 H12 O6+6O2

endothermic

taking heat in

broad surface area for more light absorption

thin for short distance to diffuse gas

veins to bring water to and around leaf

guard cells open and close stomata to regulate gas exchange

air spaces between cells to allow for easy co2 intake and oxygen outtake

temperature, co2 concentration, light intensity, chlorophyll concentration

the factor that prevents the reaction from continuing

cut pondweed at an angle to encourage photosynthesis, place the pondweed in an upside down funnel in a beaker of water, cover the top of the funnel with a boiling tube, place an led lamp at intervals away from the beaker using a meter stick, record how many bubbles appear over equal amounts of time

as the distance between the plant and light increases, the light intensity decreases by 1/ the factor^2

e.g if the distance doubles, the intensity falls by 1/4 (2^2 = 4)

plants convert glucose into carbohydrates such as cellulose to strengthen cell walls

most glucose is converted to starch as starch is insoluble and will not affect the water transport in a plant, glucose is soluble and therefore may affect the plant’s water transport

starch is a plant’s main energy store and is used in respiration

glucose can be converted into amino acids using minerals and nitrates from the soil, low mineral soils may not allow this to happen

carnivorous plants can survive in low mineral soils as they obtain mineraks from the animals they eat, e.g venus fly traps

glucose can be converted into fats and oils in order to strengthen the plant or be in the seeds for extra food during germination

greenhouses can have their factors controlled using computer software such as co2 concentration and temperature in order to grow plants in optimum conditions

fast growing plants, quicker and possibly more profits, less labour for digging out fields and checking plants, less wasted plants, more output to help rising demand

very very expensive to start up, requires people who have knowledge of the software

respiration that uses oxygen

glucose + oxygen → water + carbon dioxide

exothermic reaction

transfers energy to the external environment

the enzymes within the mitochondria allow for respiration

making new cell material, breaking down large molecules/ digestion, regulating temperature (keeping warm or cool), converting nutrients into amino acids and therefore protein, moving minerals from the soil to root hair cells

glycogen to be converted into glucose for more respiration

during exercise as the muscles contract harder and faster and need more for respiration

increased heart rate to transport more oxygen to muscles and co2 away, increased breath rate to increase oxygen input and co2 output, glycogen converting to glucose for more respiration

respiration that takes place without oxygen

glucose →lactic acid

sometimes we do not have enough oxygen input when exercising but still need energy

doesnt create as much energy as aerobic respiration, not as efficient as glucose molecules are not completely broken down, created lactic acid which results in oxygen debt

high use and high build up of lactic acid

the amount of oxygen needed to transfer lactic acid back into glucose after exercise

you need oxygen in your body to transfer the lactic acid back into glucose

plants and microorganisms

some microorganisms that respire anaerobically produce lactic acid to form some food products such as yoghurt

glucose → ethanol + carbon dioxide

fermentation

widely used in the food industry to make bread and alcohol

sum of all reactions that take place in a cell or in the body

respiration, photosynthesis, converting substances into urea for excretion, glucose making amino acids and therefore making proteins

organ that is responsible for many metabolic functions

converting lactic acid to glucose, detoxifying poisonous substances such as ethanol in alcoholic drinks, passing breakdown product into the blood to be excreted in urine via the kidneys, breaking down old worn out blood cells and storing the iron until needed for synthesising new ones

transferred to glycogen to be stored for future

blood flowing through muscles