4.2.1 Aerobic and anaerobic respiration

Created by

Cards (11)

What is cellular respiration?
● A series of chemical reactions that release / transfer energy from glucose
● Occurs continuously in all living cells
● Exothermic reaction
Describe how energy released in respiration is used
● Chemical reactions to build larger molecules (eg. metabolism)
● Keeping warm (birds and mammals only)
● Movement eg. muscle contraction in animals
Glucose + oxygen → carbon dioxide + water
Aerobic respiration
(all cells)
Reactants: Oxygen + glucose
Oxidation of glucose: Complete
Relative amount of energy transferred: High - lots per glucose molecule
Products: CO2 and water
Anaerobic respiration
in animal cells
Reactants: Glucose only; no oxygen
Oxidation of glucose: Incomplete
Relative amount of energy transferred: Low - little per glucose molecule
Products: Lactic acid
Anaerobic respiration in plant / yeast cells
Reactants: Glucose only; no oxygen
Oxidation of glucose: Incomplete
Relative amount of energy transferred: Low - little per glucose molecule
Products: Ethanol and CO2
Explain the economic importance of anaerobic respiration in yeast
● Fermentation (anaerobic respiration in yeast) is used in...
○ Production of bread → CO2 makes dough rise
○ Production of alcoholic drinks → ethanol is a type of alcohol
why is this statement wrong?
“Respiration makes / creates energy.”
Respiration releases, or transfers energy. Energy can’t be created.
Why is this statement wrong?
“Respiration is breathing.”
Breathing is bringing air in / out of the lungs. Respiration is a series
of chemical reactions in cells to release energy.
Why is this statement wrong?
“Respiration only occurs in animal cells.”
Respiration happens in every cell, including plant cells.
Explain why death of a pond snail in a test tube causes
CO2 concentration to increase. (3)
● Snail is being decayed / decomposed
● By decomposers / bacteria
● Respiration (of decomposers) releases CO2