B2.6 - Aerobic and Anaerobic Respiration Flashcards
What are the chemical reactions in the cell controlled by?
Enzymes.
During aerobic respiration, chemical reaction occur that…
- use glucose and oxygen
- release energy
Where does most of aerobic respiration take place?
In the mitochondria.
What is the equation for aerobic respiration?
glucose + oxygen —> carbon dioxide + water (+ energy)
How is energy released during respiration used?
- to build larger molecules from smaller ones
- to enable muscles to contract
- to maintain a steady body temperature in colder surroundings
- in plants, to build up sugars, nitrates and other nutrients into amino acids which are then built up into proteins.
What changes occur in the body during exercise?
- heart rate increases
- rate and depth of breathing increases
What effect does an increase in breathing and heart rate have on the muscles?
An increase in blood flow to the muscles means an increase to the supply of sugar and oxygen and increase the rate of removal of carbon dioxide.
How do muscles store glucose?
As glycogen, which can then be converted back to glucose for use during exercise.
What happens during exercise if the muscles have insufficient oxygen?
They use anaerobic respiration to obtain energy.
Why is lactic acid produced during anaerobic respiration?
Because it is the incomplete breakdown of glucose.
Why is much less energy released by anaerobic respiration?
The breakdown of glucose is not complete.
Why does oxygen debt have to be repaid?
In order to oxidise lactic acid to carbon dioxide and water.
What happens when muscles are subjected to long periods of activity?
They become fatigued, so stop contracting efficiently.
How is muscle fatigue caused?
By the build up of lactic acid.
How is lactic acid removed?
By blood flowing through the muscles.
