Biology π | Respiration | 12 Flashcards
What are the uses of energy in living organisms?
- Cell division
- Muscle contraction
- Protein synthesis
- Active transport
- Growth
- Passage of nerve impulses
- Maintaining constant body temperature
Define aerobic respiration
The chemical reactions in cells that use oxygen to break down nutrient molecules to release energy.
What is the word equation for aerobic respiration?
glucose + oxygen β carbon dioxide + water
What is the chemical equation for aerobic respiration?
C6H12O6 + 6O2 β 6CO2 + 6H2O
Define anaerobic respiration.
The chemical reactions in cells that break down nutrient molecules to release energy without using oxygen.
What is the word equation for anaerobic respiration in yeast?
glucose β ethanol + carbon dioxide
What is the word equation for anaerobic respiration in the muscles during exercise?
glucose β lactic acid
What is the chemical equation for anaerobic respiration in yeast?
C6H12O6 β 2C2H5OH + 2CO2
What is another word for anaerobic respiration in yeast?
Fermentation.
When do we carry out anaerobic respiration?
When in vigorous exercise, and our lungs and heart cannot supply oxygen to muscles as fast as needed.
What are the drawbacks of aerobic respiration?
- Requires oxygen
- Happens at a relatively slow pace
When do humans anaerobically respire?
When we are exercising too strenuously to have enough oxygen to break down glucose into energy.
What are the drawbacks of anaerobic respiration?
- It releases less energy per glucose molecule than with aerobic respiration.
- It causes a buildup of lactic acid in muscles, causing oxygen debt
What is oxygen debt?
The extra oxygen we require after strenuous exercise to break down the lactic acid built up in our muscles.
Why does our heart rate remain high for a few minutes after exercise?
So that we can supply enough oxygen to break down remaining lactic acid (pay back oxygen debt).
Where is lactic acid broken down?
Our blood takes the lactic acid to the liver.
How can we set up an investigation that looks at the effect of temperature on respiration in yeast?
- Two test tubes
- Corks with holes on both
- A pipe that can reach from the air in tube a to tube bβs indicator (limewater/hydrogen carbonate)
- Another pipe in tube B that connects air in the tube to atmospheric air.
How can we investigate the effect of temperature on respiration in yeast?
- Boil water, to drive off dissolved air
- Dissolve small amount of sugar in boiled water
- When cool, add yeast and stir with glass rod } in tube A
- Trickle liquid paraffin into tube A
- Set up an identical apparatus but with boiled yeast
- Leave apparatus in warm place
- After half an hour, observe changes in indicator.
