B9 Respiration Flashcards
what is energy needed for?
movement
chemical reactions to build larger molecules
keep warm
what is cellular respiration?
a process which supplies the body with the energy needed
what type of reaction is cellular respiration?
an exothermic reaction as it releases energy
where does cellular respiration take place?
in all living cells
what happens in aerobic respiration?
glucose is reacted with oxygen
this produces carbon dioxide and water and releases energy
why does aerobic respiration release a lot of energy?
the glucose molecule is being fully oxidised
when do muscle cells respire anaerobically?
when there is a shortage of oxygen
what happens during anaerobic respiration in muscle cells?
glucose is converted to lactic acid and this releases energy
why does anaerobic respiration produce less energy than aerobic respiration?
the oxdiation of glucose is incomplete
what happens in anaerobic respiration in plant/yeast cells?
glucose is converted to ethanol and carbon dioxide
energy is also release
what is the anaerobic respiration of yeast called?
fermentation
what is fermentation used for?
making alcoholic drinks - the alcohol is ethanol produced in fermentation
make bread - carbon dioxide creates bubbles in the dough, making it rise
what does the body need during exercise?
lots of energy for muscle contraction
what happens when aerobic respiration increases?
the body cells require more oxygen
how does the body take in more oxygen during exercise?
breathing rate and breathing volume increases
heart rate increases to pump oxygenated blood around the body
when does anaerobic respiration take place?
when not enough oxygen is being supplied to the muscles
what does lactic acid cause in muscles?
a build up of lactic acid causes the muscles to become fatigued
this means the muscles stop contracting efficiently
what happens to lactic acid built up in the muscles?
it is taken out of the muscles by the blood and taken to the liver
it is then turned back to glucose in a series of chemical reactions
this requires oxygen
what is the oxygen debt?
the amount of extra oxygen needed after exercise to deal with the accumulated lactic acid
what is metabolism?
the sum of all the chemical reactions in a cell or the body
what is glycogen?
a storage form of glucose in humans
what is needed to form a lipid molecule?
1 molecule of glycerol
3 molecules of fatty acid
where are lipid molecules found?
the cell membrane
what are excess proteins broken down into?
urea
what is urea excreted by?
the kidneys
