lipids Flashcards
4 uses of lipids
insulation (thermal and electrical)
energy source + store
protection
steroid hormones from cholesterol
what steroid hormones from cholesterol are there
testosterone
oestrogen
progestrone
how do elements in lipids compare to elements in carbs
the same except less oxygen
describe the structure of a phospholipid
polar, hydrophilic head
hydrophobic tails
define hydrophilic
attracted to water
define hydrophobic
repels water
monoglycaride
1 fatty acid + 1 glycerol molecule
triglycaride
3 fatty acids + 1 glycerol molecule
2 features of triglycerides
insoluble - hydrophobic tails
not polar - evenly distributed charges
how is a triglyceride formed
glycerol + fatty acid in a condensation reaction forming 3 ester bonds
when are fatty acids solid + examples
longer chain
animal fats butters
when are fatty acids liquids + examples
shorter chain
contain doble c=c bonds
oils in plants
unsaturated
can the R group of a fatty acid be saturated or unsaturated
both
describe the structure, properties and examples of saturated fatty acids
Structure: Have no double bonds between carbon atoms in the R group, resulting in a straight chain.
Properties: Can pack closely together, leading to solid forms at room temperature (e.g., butter).
Examples: Commonly found in animal fats.
describe structure, properties and examples of unsaturated fatty acids
Structure: Have one or more double bonds in the R group, causing a kink in the chain.
Properties: Cannot pack as closely together, resulting in liquid forms at room temperature (e.g., oils).
Examples: Found in plant oils and fish.
difference between phospholipids and triglyceride
in phospholipids, one of the fatty acids of a triglyceride is substituted by a phosphate-containing group
features of triglycerides
store energy
waterproofing
insulation
buoyancy
what are triglycerides good at storing energy
many C-H bonds making them good for energy storage
releases a lo of energy when oxidised
why are triglycerides good for waterproofing
hydrophobic nature
fatty acid chains are non-polar + repel water
why are triglycerides good insulators
non polar - dont conduct electricity or heat well
= thermal and electrical insulation
why are triglycerides good at being buoyant
low density helps animal s to float
features of phospholipids
hydrophobic
bilayer
selective permeability
why are phospholipids hydrophilic
water attracting phosphate heads
and hydrophobic fatty acid tails
forming phospholipid bilayer
how is phospholipid bilayer selectively permeable
allowing certain molecules to pass while keeping others out
