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‘greek’ –>
μεταβολή
metabolē
“change”
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(‘metabolism’ is the set of ‘life-sustaining chemical transformations’ within the cells of ‘living organisms’)
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(the 3 main purposes of ‘metabolism’ are…)
1
“the conversion of food/fuel to energy to run cellular processes”
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2
(the ‘conversion’ of food/fuel to ‘building blocks’ for…)
‘proteins’
‘lipids’
‘nucleic acids’
(some) ‘carbohydrates'”
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3
“the elimination of nitrogenous wastes”
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(these ‘enzyme-catalyzed reactions’ allow organisms to…)
*’grow’ + ‘reproduce’*
*maintain their structures*
*respond to their environments*
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(the word ‘metabolism’ can also refer to the sum of all chemical reactions that occur in ‘living organisms’, including ‘digestion’ + ‘the transport of substances into / between different cells’, in which case the set of reactions within the cells is called intermediary metabolism or intermediate metabolism)
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(‘metabolism’ is usually divided into 2 categories…)
‘catabolism’
(the breaking down of ‘organic matter’, for example, by ‘cellular respiration’)
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‘anabolism’
(the building up of components of ‘cells’ such as ‘proteins’ and ‘nucleic acids’)
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(usually, breaking down releases energy and building up consumes energy)
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(the ‘chemical reactions’ of ‘metabolism’ are organized into ‘metabolic pathways’, in which 1 chemical is transformed through a series of steps into another chemical, by a sequence of ‘enzymes’)
(‘enzymes’ are crucial to ‘metabolism’ because they allow organisms to drive ‘desirable reactions’ that require ‘energy’ that will not occur by themselves, by coupling them to ‘spontaneous reactions’ that release ‘energy’)
(‘enzymes’ act as ‘catalysts’ that allow the ‘reactions’ to proceed more rapidly)
(‘enzymes’ also allow the ‘regulation’ of ‘metabolic pathways’ in response to changes in the cell’s environment or to ‘signals’ from other ‘cells’)
(the ‘metabolic system’ of a particular ‘organism’ determines which substances it will find ‘nutritious’ and which ‘poisonous’)
(for example, some ‘prokaryotes’ use ‘hydrogen sulfide’ as a ‘nutrient’, yet this gas is ‘poisonous’ to ‘animals’)
(the ‘speed of metabolism’ (aka the ‘metabolic rate’) influences how much food an organism will require, and also affects how it is able to obtain that food)
(a striking feature of ‘metabolism’ is the similarity of the ‘basic metabolic pathways’ and components between even vastly different species)
(for example, the set of ‘carboxylic acids’ that are best known as the ‘intermediates’ in the ‘citric acid cycle’ are present in all known ‘organisms’, being found in species as diverse as the unicellular bacterium escherichia coli and huge multicellular organisms like ‘elephants’)
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(these striking similarities in ‘metabolic pathways’ are likely due to their early appearance in ‘evolutionary history’ / their retention because of their ‘efficacy’)
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*🌈✨ *TABLE OF CONTENTS* ✨🌷*
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🔥🔥🔥🔥🔥🔥*we won the war* 🔥🔥🔥🔥🔥🔥