b4 - bioenergetics Flashcards
what is photosynthesis
plants absorb carbon dioxide and water from the environment and use light energy to turn them into glucose and oxygen
what type of reaction is photosynthesis
endothermic
when do plants use glucose
respiration, making cellulose, storing it as starch, store as fat, producing amino acids
what can photosynthesis be affected by
light intensity, carbon dioxide concentration, temperature
how do greenhouses make plants grow faster
made of glass so lots of light, artificial lights at night, trap heat and use heaters in cold days, pump carbon dioxide in
how can you measure photosynthesis
count the number of bubbles made from oxygen from underwater plants in a minute with a light source at a certain distance, then move light source a bit further away and do it again
what does cellular respiration do
transfers energy to an organism from food in all living cells all the time
why do organisms need energy
for movement and to keep warm and for chemical reactions
what type of reaction is respiration
exothermic
what is aerobic respiration
glucose and oxygen are converted into carbon dioxide and water, glucose is completely oxidised, the same equation as photosynthesis but reversed
what is anaerobic respiration
used if there isn’t enough oxygen, in muscles glucose turns into lactic acid, glucose isn’t fully oxidised meaning less energy is released than in aerobic respiration
what is fermentation
anaerobic respiration in yeast cells, glucose goes to ethanol and carbon dioxide, used when making bread as carbon dioxide makes bread rise, also used in making alcoholic drinks as ethanol is alcohol and carbon dioxide makes the fizz
what is oxygen debt
the extra oxygen needed to remove the lactic acid
what does the liver convert lactic acid into with oxygen
glucose
what is the metabolism
combined total of all the reactions that take place in the body
