Chapter 12 Flashcards
Respiration (8 cards)
State the uses of energy in living organisms
muscle contraction
protein synthesis
cell division
active transport
growth
the conduction of electrical impulses by nerve cells
homeostasis - maintenance of a constant body temperature
Investigate the effect of temperature on respiration in yeast
yeast respires anaerobically producing CO₂ – by measuring the volume of CO₂ via a syringe attached to a closed test-tube containing yeast and glucose solution – use a water bath to control the temperature
As the temperature increases, the volume of CO₂ produced also increases optimum 35–40°C after which slow down the rate of gas production – enzymes involved in respiration start to denature
Describe aerobic respiration
the chemical reactions in cells that use oxygen to break down nutrient molecules to release energy
State the equation for aerobic respiration
glucose + oxygen → carbon dioxide + water
C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O
Describe anaerobic respiration
the chemical reactions in cells that break down nutrient molecules to release energy without using oxygen
— releases much less energy per glucose molecule than aerobic respiration
State the equation for anaerobic respiration in yeast
glucose → alcohol + carbon dioxide
C₆H₁₂O₆ → 2C₂H₅OH + 2CO₂
State the word equation for anaerobic respiration in muscles during vigorous exercise
glucose → lactic acid
Explain the concept of O₂ debt
When tissues are respiring very fast, the O₂ supply is not fast enough to cope, so tissues such as muscles start to respire anaerobically instead causing a build up of lactic acid creating an O₂ debt
– to remove the O₂ debt the lactic acid needs to undergo aerobic respiration in the liver
– the heart rate remains high to transport lactic acid in the blood from the muscles to the liver rapidly
– the rate and depth of breathing remains high to supply oxygen for aerobic respiration of lactic acid
