Biomolecules: Lipids

What is a Lipid

a compound that is insoluble in water but soluble in an organic solvent

what is a fat

lipid that is solid at room temprature

what is an oil

lipid that is liquid at room temprature

what is a lipids function? (3)

• fuel molecules

• provide insulation

• essensial components of cell membranes

what does amphipathic mean

compounds which exhibit both hydrophilic and hydrophobic properties

why is the orientation around the double bond is in the cis conformation rather than the trans?

important for the structure because each cis double bond inserts a bend into the hydrocarbon tail

Triacylglycerols structure

uncharged esters of three fatty acids with glycerol

triacylglycerols function

triglycerides/TAGs are highly concentrated stores of metabolic energy because they are reduced and contain no water

What is adipose tissue

a major site of tag accumulation and specialised for tag synthesis

what are liquid droplets

large globules formed by TAGs

Phospholipids structure (2)

• one or more fatty acids

• a platform to which the fatty acids are attached

phospholipid function

major component of cell membrane

what is a glycerophospolipid, what does it contain?

class of phospholipid that make up a large proportion of the membrane in mammals, also contains a glycerol backbone

glycerophospolipids structure

contains a glycerol backbone

what is membrane fluidiity controlled by?

fatty acid composition

what is sphingolipids

not derived from glycerol, constituties around 10-20 percent of the cell membrane

what is the backbone of sphingolipids

sphingosine

what is a glycolipid

class of lipid that has a carbohydrate attached to the hydrophilic head

what is cholesterol

part of a group called sterioids

what is the function of cholesterol?

stabilizes the cell membrane

what are the three derivatives of cholesterol?

• sex hormones

• cortiosteriods

• mineralocorticods

what are bile salts

polar derivates of cholesterol

what do bile salts act as?

detergents in the small intestine to aid with the digestion of fats