B9 Respiration Flashcards
what is aerobic respiration?
an exothermic reaction in which glucose reacts with oxygen to release energy
what is the word equation for aerobic respiration?
glucose + oxygen –> carbon dioxide + water (+energy)
where does aerobic respiration take place?
the mitochondria
why do organisms require the energy released by respiration?
- synthesis of larger molecules
- muscle contraction
- maintenance of body temperature
- active transport
what is anaerobic respiration?
an exothermic reaction in which glucose is broken down to release energy in the absence of oxygen
what is the equation for anaerobic respiration in humans?
glucose –> lactic acid (+energy)
what is the equation for anaerobic respiration in plants?
glucose –> ethanol + carbon dioxide
why is anaerobic respiration less efficient than aerobic respiration?
glucose is not completely broken down, so less energy is transferred
why can anaerobic respiration lead to muscle fatigue?
lactic acid builds up in the muscles, preventing efficient muscle contraction
what is an oxygen debt?
the amount of oxygen needed to convert lactic acid back into glucose after anaerobic respiration
what is fermentation?
a type of anaerobic respiration that occurs in yeast cells
what is the equation for fermentation?
glucose –> ethanol + carbon dioxide
why is the fermentation reaction important?
it is used in the production of alcoholic drinks and bread
what are the differences between aerobic and anaerobic respiration?
- aerobic respiration involves oxygen, anaerobic does not
- aerobic respiration releases more energy than anaerobic
- anaerobic respiration produces lactic acid or ethanol and carbon dioxide, aerobic respiration produces carbon dioxide and water
how do muscles store glucose?
as glycogen
what changes take place when muscular activity increases in the body?
- heart rate increases and arteries dilate, increases flow of oxygenated blood to muscles
- breathing rate increases and breathing is deeper, increases the rate of gaseous exchange
- stored glycogen is converted back into glucose
how is lactic acid transported away from the muscles?
blood flow through the muscles transports lactic acid to the liver, where it is oxidised back to glucose
what is metabolism?
the sum of all chemical reactions that take place in a cell or organism
how cells use the energy transferred by respiration?
to continuously carry out enzyme-controlled processes which leads to the synthesis of new molecules
