Respiration Flashcards
Define respiration
The process where glucose is broken down to release energy in the form of ATP, in all living cells.
Define aerobic respiration
The breakdown of glucose in presence of oxygen with the release of 38 ATP molecules. Carbon dioxide and water are relased as waste products
What are the chemical process during aerobic respiration
Glycolysis takes place in the cytosol where 1 glucose molecules is broken down to form 2 molecules of pyruvate and 2 ATP molecules in the process. If oxygen is present, 2 molecules of pyruvate will enter the mitochondrion where they are complete oxidised into carbon dioxide and water. Each pyruvate molecules yields 18 ATP molecules. Including glycolysis, a total 38 molecules of ATP are produced from a molecule of glucose during aerobic respiration
Define anaerobic respiration
The breakdown of glucose in the absence of oxygen, resulting in the release of lesser energy than aerobic respiration
Define chemical processes occuring in anaerobic respiration
Glycolysis of 1 molecule of glucose in cytosol yields two molecules of pyruvate and two molecules of ATP. In absence or low concentrations of oxygen, pyruvate will not enter mitochondrion. Pyruvate is converted into lactic acid or ethanol and carbon dioxide which are removed as metabolic waste products
How is anaerobic respiration used in alcohol fermentation
Pyruvate is converted into ethanol and carbon dioxide. Yeast is used in beer brewing and bread making, where carbon dioxide generated allows dough to rise
How is anaerobic respiration used in lactic acid fermentation
Pyruvate is converted into lactic acid, with no release of carbon dioxide. Lactic acid fermentation by certain fungi and bacteria are used in production of cheese and yoghurt
What are the uses of ATP in body of humans
Muscle contraction, protein synthesis, cell division, active transport, growth, the passage of nerve impulses, maintainence of constant body temperature
Why must muscle cells respire anaerobically during exercise (lactic acid in muscles essay part 1)
During vigorous muscular contractions, muscle cells first respire aerobically. Breathing rate increaes to remove CO2 and take in O2 at faster rate. Heart rate will also increase so that oxygen can be transported to muscles at faster rate. There is limit to increase in rate of brething and heartbeat, therefore there is insufficient oxygen to meet demands of vigorous muscular contractions. In such conditions, muscle cells respire anaerobically for short durations in order to meet energy demands of the activity
How does anaerobic respiration help in exercise (lactic acid in muscles essay part 2)
Extra energy released by anaerobic respiration supplements the energy released by aerobic respiration to allow muscles to continue contracting. When aerobic respiration occurs, there is build-up of lactic acid in muscle cells. Since there is insufficient oxygen to meet demands of vigorous muscular contractions, muscles are said to incur oxygen debt. Lactic acid concentrations build up slowly in muscles and may eventually become high enough to cause fatigue and muscular pains. Body needs to rest and recover
Describe recovery period after vigorous exercise
Breathing rate continues to be high for some time. This is to provide ‘extra’ oxygen to repay oxygen debt. Lactic acid is removed from muscles and transported to liver. In liver, some of lactic acid ix oxidised to release energy. This energy converts remaining lactic acid back to glucose. When all lactic acid has been converted to glucose, oxygen debt is repaid. Glucose is then transported back to muscles and body is now ready for another race
What are similarities between aerobic and anaerobic respiration
Both produce ATP, require glucose and glucose is frist broken down into pyruvate in the cytosol
What are differences between aerobic and anaerobic respiration
- Requires oxygen, does not
- Produces water and carbon dioxide as waste products, produces either lactic acid or ethanol and carbon dioxide or waste products
- Pyruvate enters mitochondria, pyruvate does not enter mitochondria
How to prevent decay of dead organisms (for control for respiration experiments)
Soak the organisms in fomalin
What can be used to see change in carbon dioxide concentration
Use hydrocarbonate indicator
Turns yellow when CO2 added, turns purple when CO2 removed, remains red if no change
