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What is Respiration?
The overall process which delivers oxygen from the environment to the cells of an organism and removes carbon dioxide from the organism.
What are the 4 levels of gas exchange?
Inhalation/Exhalation
External Respiration
Internal Respiration
Cellular Respiration
How long does it take for gas exchange to occur?
The whole process occurs in seconds.
A change in air pressure causes air to move from an area of _______ pressure (the lungs) to an area of ______ pressure (outside the body).
High, Low
What is the Law of Diffusion?
Particles move from an area of high concentration to an area of low concentration. This applies to gases. E.g. If you spray perfume in one corner of the class… eventually it can be smelled at the other side as the perfume molecules diffuse through the air.
What 3 factors affect diffusion?
Medium (air or water)
Surface area
Distance of diffusion
Respiration takes place in what environment?
Respiration must occur in a moist enviroment so that oxygen and carbon dioxide are dissolved in water.
What is the main function of the respiratory system?
To ensure that oxygen is brought into the body and made available to each cell that needs it, and that carbon dioxide can leave each cell and be removed from the body.
Explain the first stage in respiration (breathing).
Inspiration (breathing in, or inhaling) and expiration (breathing out, or exhaling)
Inspiration moves air from outside the body into the lungs inside the body.
Expiration moves air from the lungs to the outside of the body
What is the 2nd stage in gas exchange?
External respiration is the exchange in oxygen and carbon dioxide between the inspired air from the lungs and the blood
This stage performs the vital function of gas exchange
Gas exchange is the delivery of oxygen from the lungs to the blood, and the elimination of carbon dioxide from the blood to the lungs
Occurs between the alveoli and blood (plasma and red blood cells)
Oxygen concentration is higher in alveoli and lower in capillaries
Carbon dioxide concentration is lower in alveoli and higher in capilaries
What is the 3rd stage in the gas exchange?
Internal respiration, is the exchange of oxygen and carbon dioxide between the blood and the body’s tissue cells
Occurs between the blood and body cells (e.g the muscle cells)
Oxygen concentration is higher in capillaries and lower in body cells
Carbon dioxide is lower in capillaries and higher in body cells
What is the 4th stage of the gas exchange?
Cellular respiration, a series of energy-releasing chemical reactions that take place within the cells.
Occurs in the mitochondria to create energy
Wate CO2 is transported out and the entire process repeats itself.
What is Cellular respiration?
The enzymatic breakdown of glucose (C6H12O6) in the presence of oxygen (O2) to produce cellular energy - ATP
C6H12O6 + 6O2 -->6 CO2 + 6H2O + 36 ATP
glucose + oxygen --> carbon dioxide + water + energy
What is the 1st -step of Cellular Respiration?
STEP 1 - Glycolysis:
Glucose is split into two pyruvate molecules (net yield of 2 ATP per glucose)
OXYGEN PRESENT - the pyruvic acid diffuses into the mitochondrion and is converted to acetyl CoA which enters the Krebs cycle. – aerobic respiration
OXYGEN ABSENT – the pyruvate is converted to lactic acid in the cytoplasm - anaerobic respiration
What is the 2nd step in cellular respiration?
STEP 2 - Citric Acid (or Krebs) Cycle
Occurs in the inner mitochondrial matrix
Aerobic process; will proceed only in the presence of O2
Net yield of 2 ATP per glucose molecule
Oxidation of glucose to CO2
What is the 3rd step in cellular Respiration?
STEP 3 - Electron Transport System:
A series of enzymes use energy from electrons and the products of Krebs Cycle to eventually produce ATP (using ATPase enzyme)
A net yield of 32 ATP per glucose molecule
A total of 6 H2O are formed when the electrons unite with O2* at the end of electron transport chain. * Note: This is the function of oxygen in living organisms
Note 
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