respiration Flashcards
is respiration exothermic or endothermic?
exothermic, as it releases energy
what are the uses of energy in the body of humans?
muscle contraction protein synthesis cell division growth maintenance of a constant body temperature
anaerobic respiration
the chemical reactions in cells that break down nutrient molecules to release energy without using oxygen
glucose is only partly broken down in the absence of oxygen and so only a little energy is released from glucose
which one releases more energy?
anaerobic releases much less energy per glucose molecule
describe anaerobic respiration taking place in muscle cells
when muscle cells lack oxygen they will respire anaerobically to obtain some energy from glucose. this is a very inefficent form of respiration as it releases only a small amount of energy from the glucose molecule
equation for anaerobic respiration in humans
glucose -> lactic acid
why do we breath faster during exercise? but
during exercise muscle cells must contract more so they need more energy. they must respire more which means that the muscle cells need more glucose and oxygen per minute. they must also get rid of the carbon dioxide produced.
the increased co2 levels in the blood causes an increas ed breathing rate. this means that the muscle cells will be provided with more glucose and oxygen per minute and more co2 will be removed per minute
why do we continue to breath faster after exercise?
whenever muscle cells do not have eneoigh oxygen during exercise they will respire anaerobically to get energy. glucose is broken down into lactic acid in the muscles.
lactic acid is associated with cramping of muscles but it is also toxic so it must be removed from the cells by the blood and carried to the liver, where it is broken down using oxygen.
we must therefore continue to breathe deeply after exercise to provide the liver with enough oxygen to break down all of the lactic acid that was formed.
in other words, the oxygen debt that developed during exercise must be repaid after exercise
respiration in yeast
glucose —> ethanol + carbon dioxide
how is yeast used?
yeast is a fungus which is used in the brewing and baling industry as it respires anaerobically producing ethanol (brewing industry) and carbon dioxide (bread making industry).
when the dough is placed into a hot oven the bubbles of trapped carbon dioxide in the dough expand causing the dough to rise.
yeast reproduces _
asexually
yeast have ________
food storage granules
equation for yeast in baking
yeast + flour + sigar + H2O -> dough
