Unit 12 - respiration Flashcards
(8 cards)
What is respiration?
Chemical reactions in cells that break down nutrient molecules to release energy. These chemical reactions are catalysed by enzymes.
State 6 purposes that the body needs respiration for
- Muscle contraction
- Protein synthesis
- Cell division and growth
- Active transport
- Passage of nerve impulses
- Maintenance of constant body temperature
What is aerobic respiration + where does it occur + equation + balanced chemical equation?
Chemical reaction in cells that uses oxygen to break down nutrient molecules to release energy. This reaction occurs in the mitochondria (sub-cellular structures).
Word formula: glucose + oxygen -> carbon dioxide + water+ ATP/energy
Balanced chemical equation: C6H12O6 + 6O2 -> 6CO2 + 6H2O
What is anaerobic respiration + where does it occur+ word formula?
Anaerobic respiration does not involve oxygen when breaking down nutrient molecules to release energy. It releases a lot less energy for each glucose molecule than aerobic respiration. It occurs in muscle cells during vigorous exercise.
Word equation: glucose -> lactic acid + energy/ATP
State and explain 3 ways that the body removes lactic acid
- Aerobic respiration in the liver to break down the lactic acid into CO2 and water
- Maintaining high heart rate for some time after stopping exercise so that the lactic acid can be transported in the blood from the muscles to the liver.
- Maintaining deeper & faster breathing for some time after stopping exercise to provide the oxygen your liver needs to break down the lactic acid
Where does lactic acid build up?
In the muscles and blood. It is dangerous and must be broken down
What is oxygen debt?
The amount of oxygen needed to break down the lactic acid in the liver
When do muscle cells switch to anaerobic respiration?
When they cannot get enough oxygen for energy to be released by aerobic respiration alone
