respiratory substrates

what nutrients are good sources of energy?

macronutrients:

fats - 9kcal/g

carbohydrates - 4kcal/g

proteins - 4kcal/g

what is a macromolecule?

a large, insoluble polymer

what are the macronutrients broken down into?

starch = glucose

carbs = glucose

protein = amino acids

lipids = glycerol + fatty acids

what do animals store glucose as?

glycerol (made from glucose)

stored in muscles

what do plants store glucose as?

convert glucose into starch and store in leaf stem and roots

how are proteins broken down?

polymers (proteins) made from amino acids (monomers) are linked together by polypeptide bonds

in digestion protease enzymes break proteins into amino acids

how are fats broken down?

molecules of glycerol, which is made up of fatty acids, are broken down by the enzyme lipase separating the glycerol backbone from the fatty acids

what are lipids used for?

lipids are insulators and make up cell membranes

why are lipids not polymers?

the backbones of lipids (glycerol) can be a massive molecule, but lipids are not made of monomers so they are not polymers