The importance of excretion 5.2.1 Flashcards
What is excretion
The process by which toxic waste products of metabolism and substances in excess of requirement are removed from the body
Give an example of excretion
The kidneys produce urine that contains the waste product urea in solution
What is excretion a key process in?
Homeostasis as it is important in maintaining metabolism - as metabolic waste can have serious negative consequences of the body if allowed to accumulate
What does metabolic waste include?
- carbon dioxide
- nitrogenous waste
- bile pigments (produced through the breakdown of haemoglobin)
How is carbon dioxide formed in the body
From the decarboxylation of respiratory substances
What is ammonia produced by?
The deamination of excess amino acids
Why do mammals have high metabolic rates?
As they are active, warm-blooded animals
How are bile pigments produced?
Through the breakdown of haemoglobin
Give examples of nitrogenous waste
Ammonia and urea
What is the source of urea
The ornithine cycle in the liver
What happens if ammonia and CO2 are allowed to accumulate or not excreted properly
They accumulate and change the cytoplasm and body fluid pH, which can cause enzymes to work less efficiently
