Chapter 9 Flashcards
Respiration
EXOthermic reaction
Organisms need energy for…
- Chemical reactions: build larger molecules
- Movement: muscle contraction
- Maintain internal body temperature (mammals and birds)
- Movement of mineral ions into roots - active transport (plants)
Aerobic respiration - with oxegyn
Takes place in mitochondria
Worded equation for glucose
Glucose + Oxygen > Carbon dioxide + Water
+ Energy
Balanced symbol equation for glucose
C6 H12 O6 + 6O2 > 6CO2 + 6 H2O (+ Energy)
Response in exercise
- Heart rate increases: more oxygenated blood to muscles and glucose
- Breathing rate and volume increases: more oxygen is taken into body
- Glycogen stored in muscles converted to glucose
Anaerobic respiration - without respiration
Less energy is released as breakdown of glucose is incomplete
Lactic acid causes muscle fatigue
Creates an oxygen debt
Worded equation
Glucose > Lactic acid (+ Energy)
Oxygen and liver
Oxygen is needed to break down lactic acid
Lactic acid is taken to the liver where it is converted back to glucose.
Fermentation Glucose
Glucose > Ethanol + carbon dioxide (+energy)
Metabolism
Metabolism is the sum of all reactions in a cell or body. Uses energy released from respiration
What do these include
Glucose → starch, glycogen, cellulose Formation of lipid molecules Formation of amino acids Respiration Break down of excess amino acids to form urea - liver
Oxygen debt
Much less energy is released during anaerobic respiration than during aerobic respiration. This is because the breakdown of glucose is incomplete.
Anaerobic respiration produces an oxygen debt. This is the amount of oxygen needed to oxidise lactic acid to carbon dioxide and water. The existence of an oxygen debt explains why we continue to breathe deeply and quickly for a while after exercise.
