Bioenergetics: Aerobic & Anaerobic Respiration Flashcards
Is aerobic respiration endothermic or exothermic?
exothermic
What is aerobic repsiration?
A reaction in which glucose reacts with oxygen to release energy which can be used by cells.
What are the word and symbol equations for aerobic respiration?
glucose + oxygen → carbon dioxide + water (+energy)
C6H12O6 + 6O2 → 6CO2 + 6H2O (+energy)
Where does aerobic respiration take place?
mitochondria
Why do organisms require the energy released by respiration
- synthesis of larger molecules from smaller ones (eg. proteins → amino acids)
- muscle contraction
- maintenance of body temperature
What is anaerobic respiration?
A reaction in which glucose is broken down to release energy in the absence of oxygen.
Is anaerobic respiration an endothermic or an exothermic reaction?
exothermic
What is the word equation for anaerobic respiration?
glucose → lactic acid (+energy)
Why is anaerobic respiration less efficient compared to 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 muscles
- this prevents efficient contraction
What is an oxygen debt?
Th 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 (+energy)
Why is the fermentation reaction important?
It is used in:
- production of bread
- production of alcoholic drinks
What are the differences between aerobic and anaerobic respiration?
- aerobic requires oxygen; anaerobic does not
- aerobic produces CO2 and water; anaerobic produces lactic acid or ethanol + CO2
- aerobic transfers a greater amount of energy
How do muscles store glucose?
as glycogen
Why does more respiration need to be done during exercise?
More energy is required due to:
- more muscular contraction being done
- heart rate increasing
- breathing rate increasing
How is lactic acid transported away from the muscles?
- blood flow through muscles transports lactic acid to the liver
- here it is oxidised back to glucose
What is metabolism?
The sum of all the reactions that take place in a cell or organism.
Give examples of metabolic reactions.
- glucose into starch/glycogen/cellulose
- glycerol and fatty acids into lipids
- respiration
- photosynthesis
- glucose and nitrate ions into amino acids
Why does breathing rate increase during exercise? (2)
- to get more oxygen into the blood (1) for use in respiration (1)
- to remove more CO2 (1) produced in respiration (1)
Why does heart rate increase during exercise? (2)
- to increase blood flowing to muscles which provides them with more oxygen and more glucose and removes CO2 and lactic acid more quickly (from the muscles
