lipids Flashcards
what are 2 types of lipids
triglycerides
phospholipids
what three types of element make up lipids
carbon, hydrogen, oxygen
what is a key feature of triglycerides
they are a good source of energy (also found in plants)
what is a key feature of phospholipids
structural role
build up cell membranes
what are lipids called
complex molecules
macromolecules
they are not polymers because the sub units are joined together but not in a repeating pattern
are lipids polymers, (why not)
lipids are not polymers, they are macromolecules ( large and complex molecules)
although in lipids subunits are joined together, they are not joined together in a repeating pattern.
are lipids polar, or non polar molecules
lipids are non polar molecules, they will not dissolve in water
what is glycerol
glycerol is an organic alcohol which has 3 hydroxyl groups (-oh) groups
what are fatty acids (in terms of acids/ alcohols)
fatty acids are organic acids that have a carboxyl group cooh joined to a hydrocarbon tail.
fatty acids are a type of carboxylic acids.
instead of drawing out a whole fatty acid, the diagram can be summarised by showing a carboxyl group -COOH attached to what
R- can be used to depict the hydrocarbon chain, instead of drawing it out.
what type of triglyceride are fats
fats are saturated triglycerides
what type of triglycerides are oils
oils are unsaturated triglycerides
at room temperature, what state are unsaturated triglycerides
unsaturated triglycerides are liquid at room temperature
at room temperature what state are saturated triglycerides
saturated triglycerides are solid at room temperature
what does monunsaturated mean
fatty acids with only one double bond between carbon atoms in the hydrocarbon chain
what does poly unsaturated mean
fatty acids with more than one double bond between carbon atoms in the hydrocarbon chain
why are unsaturated fatty acids liquid at room temperature
-the prescence of double bonds between the carbon atoms in the hydrocarbon chain causes the fatty acid chains to bend
this bending pushes the triglyceride molecules further apart from each other than saturated triglyceride molecules.
the double bonds kink the carbon chain so unsaturated fats cannot pack together tightly
the spaces between the triglyceride molecules weakens the intermolecular forces forming a liquid at room temperature
why are saturated fatty acids solid at room temperature and compact
there are stronger intermolecular forces between the triglyceride molecules because they are closely packed together.
role of phospholipids
and why do they have one unsaturated fatty acid chain and one saturated fatty acid chain.
phospholipids have a structural role
they do not store fats
phospholipid bilayer due to hydrophillic head and hydrophobic fatty acid chains which point towards centre of the sheet and the hydrophillic heads are positioned outwards, they protect the fatty acid chains from the water.
phospholipid monolayer
hydrophillic head of phospholipid molecule sticking into the water and the fatty acid tails stick out of the water
cholesterol structure
the hydroxyl group is polar and therefore hydrophyllic and the rest of the molecule is hydrophobic
where does the body manufacture sterol
body manufactures sterols in the liver and the intestines it has an important role in the formation of cell membranes
what is manufactured using cholesterol
vitamin D
bile
steroid hormones
what are biological roles of lipids
-membrane formation and the creation of hydrophobic barriers
-hormone production
-electrical insulation necessary for nerve impulse transmission
waterproofing for examples birds feathers lipids are non polar hydrophobic
