respiration is the process of transferring energy from the breakdown of glucose and happens in every living thing, it uses oxygen so is aerobic respiration and is exothermic as it transfers energy.
3 examples of how organisms use energy transferred by respiration
-to build up larger molecules from smaller ones(proteins from amino acids)
-animals use it so muscles can contract
-mammals and birds use it to keep their body temperature steady when cold
metabolism is all the chemical reaction in an organism, ‘metabolic rate’ is the rate of these reactions
making big molecules
synthesis
breaking down molecules
catabolism
carbohydrates
can be simple sugars like glucose, or much longer complex molecules like starch, cellulose and glycogen
proteins
made from amino acids, amino acids can be made from glucose but this needs nitrogen, plants get nitrogen from nitrates in the soil
lipids
made from 3 fatty acids linked by glycerol, fatty acids have long hydrocarbon chains like alkanes and alkenes
FATTY ACIDS+GLYCEROL=LIPID
-in some metabolic reaction larger molecules are made from smaller ones(e.g. glucose joined together to make starch)
-in other metabolic reactions large molecules are broken down into smaller ones(e.g. glucose broken down in respiration)
