Excretion Unit 1 Mod. 2 A2 Biology
- Created by: Captain Jack Sparrow
- Created on: 19-06-13 10:08
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- Excretion
- 2 Main Substances Excreted
- Carbon Dioxide (CO2)
- Produced By:
- Every living body cell (due to respiration)
- Where excreted?
- Breathing Out
- Process?
- CO2 - waste product of aerobic respiration from every living body cell
- Enters bloodstream (mostly in form of hydrogencarbonate ions)
- Transported to Lungs
- CO2 diffuses into Alveoli
- Excreted as we breathe out
- CO2 diffuses into Alveoli
- Transported to Lungs
- Enters bloodstream (mostly in form of hydrogencarbonate ions)
- CO2 - waste product of aerobic respiration from every living body cell
- Process?
- Breathing Out
- Produced By:
- Urea (Nitrogen Containing Compounds)
- Produced By:
- Liver (from excess amino acids)
- Where excreted?
- Urine via Uretha
- Process?
- Excess amino acids
- Broken down in Liver
- Passed into bloodstream
- Transported to Kidneys
- Dissolved in Blood Plasma
- In Kidneys, Urea removed from blood to become part of urine
- Stored in Bladder
- Excreted via Uretha
- Stored in Bladder
- Transported to Kidneys
- Called -deamination
- Passed into bloodstream
- Broken down in Liver
- Excess amino acids
- Process?
- Urine via Uretha
- Formed By
- Ammonia + CO2
- Makes
- Urea + Water
- Makes
- Ammonia + CO2
- Produced By:
- Carbon Dioxide (CO2)
- Definition
- The removal of metabolic waste from the body
- Reason for excretion
- CO2
- Excess CO2 toxic
- Has 3 main effects
- AS - level "chloride shift"
- Most CO2 in blood as Hydrogencarbonate ions
- Forming these ions also forms Hydrogen ions
- H+ ions combine with haemoglobin
- Compete with oxygen for space on haemoglobin
- Therefore can reduce Oxygen transport
- Compete with oxygen for space on haemoglobin
- H+ ions combine with haemoglobin
- Forming these ions also forms Hydrogen ions
- Most CO2 in blood as Hydrogencarbonate ions
- CO2 combines directly with haemoglobin to form carbaminohaemoglobin
- This molecule has a lower Affinity for oxygen than normal haemoglobin
- Excess CO2 can cause respiratory acidosis
- CO2 dissolves in blood plasma
- CO2 + H2O
- H2CO3
- Dissociates to
- H+ and HCO3-
- H+ ions released therefore lowering pH
- H+ and HCO3-
- Dissociates to
- H2CO3
- CO2 + H2O
- CO2 dissolves in blood plasma
- AS - level "chloride shift"
- Has 3 main effects
- Excess CO2 toxic
- Nitrogenous Compounds
- Body can't store proteins/ amino acids
- Transported to Liver
- Poentially toxic amino acid group removed (deamination)
- Amino group initially forms highly toxic and highly soluble compound Ammonia
- In Liver, converted into less toxic and less soluble Urea
- Urea transported (in blood plasma) to Kidneys for excretion
- Remaining Keto acid
- Used directly in respiration
- converted to carbohydrate or stored as fat
- Remaining Keto acid
- Urea transported (in blood plasma) to Kidneys for excretion
- In Liver, converted into less toxic and less soluble Urea
- Deamination
- Amino Acid + Oxygen
- Makes
- Keto Acid + Ammonia
- Makes
- Amino Acid + Oxygen
- Amino group initially forms highly toxic and highly soluble compound Ammonia
- Poentially toxic amino acid group removed (deamination)
- Transported to Liver
- Body can't store proteins/ amino acids
- CO2
- Remember!
- Do not confuse Egestion or Elimination with Excretion!
- 2 Main Substances Excreted
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