Lipids - cholesterol Flashcards
what is a steroid alcohol
a lipid not made from glycerol or fatty acids
what is another name for a steroid alcohol
sterols
what are sterols not classed as
fats or oils
what is a sterol
a complex alcohol molecule based on a four carbon ring structure with a hydroxyl group at one end.
what characteristics so sterols have
dual hydrophillic and hydrophobic characteristics
which part of the sterol is hydrophillic
the hydroxyl group is polar and hydrophilic
which part of the sterol is hydrophobic
the rest of the molecule apart from the hydroxyl group
what is cholesterol
a small and hydrophobic molecule that sits in the middle of the hydrophobic part of the bilayer
what does cholesterol consist of
four based carbon rings or isoprene units
what does cholesterol do
it regulates the fluidity by keeping the membrane fluid at room temeperature and stops it becoming too fluid or stiff at high temperatures
where is cholesterol mainly made
the liver and intestines. plants have a cholesterol in their membranes
what is manufactured using cholesterol
vitamin D, bile, and steroid hormones
give examples of steroid hormones
testosterone and oestrogen
what can cholesterol do because it is small and hydrophobic
it can pass through the hydrophobic part of the cell membrane and any other membrane inside the cell
