- Created by: maddieecarr
- Created on: 27-11-19 16:40
B9.1: Aerobic Respiration
- cellular respiration is an exothermic reaction that occurs continuously in living cells.
glucose + oxygen -----> carbon dioxide + water + energy transferred to the environment.
- the energy transferred supplies all the energy needed for living processes.
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B9.2: The Response to Exercise
- the energy that is transferred during respiration is used to enable muscles to contract.
- during exercise the human body responds to the increased demand for energy.
- body responses to exercised
- increased heart rate, breathing rate and breath volume
- glycogen stores in muscles are converted to glucose for cellular respiration.
- the flow of oxygenated blood to the muscles increases.
- these act to increase the supply of glucose and oxygen to muscles are removal of carbon dioxide from the muscles.
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B9.3: Anaerobic Respiration
- if muscles work for a long time, they become fatigues and don't contract efficiently. if they don't get enough oxygen they respire anaerobically.
- anaerobic respiration is respiration without oxygen. glucose is incompletely broken down and forms lactic acid in animals.
- the anaerobic breakdown of glucose produces less energy that aerobic respiration.
- after exercise oxygen is needed to break down the lactic acid. the amount of oxygen needed is called oxygen debt.
- anaerobic respiration in plants and some microorganisms like yeast produce ethanol and carbon dioxide.
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B9.4: Metabolism and the Liver
- metabolism is the sum of all the reactions in the body
- the energy transferred by respiration in cells is used by an organism for the enzyme-controlled processes of metabolism which creates new molecules.
- metabolism includes the converion of glucose to starch, glycogen and cellulose.
- it also includes the formation of lipid molecules, the use of glucose and nitrate ions to form amino acids which are used to synthesise proteins and breakdown excess protein into urea.
- blood flows through the muscles and transports lactic acid to the liver where it is converted back into glucose.
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