1.3: Lipids Flashcards
What 3 elements are lipids made of
carbon, hydrogen, oxygen
Why do lipids form good waterproofing layers?
because they are insoluble in water
State 3 properties of lipids
compact
insoluble
high energy yield
State 7 functions of lipids
thermal insulation
cell membrane structure
energy store
waterproofing
source of metabolic water
buoyancy
protection
what is the structure of a triglyceride
simple lipid - 3 fatty acids bonded to one glycerol
what is the structure of compound lipids
glycerol, fatty acids and a group/molecule/compound
What is the chemical formula of glycerol
C3H8O3
What is the general formula of fatty acids
CH3(CH2)nCOOH
what chemical group does glycerol belong to?
alcohols
What are 2 different types of fatty acids?
saturated and unsaturated
what is the difference between a saturated fatty acid and an unsaturated fatty acid?
sat = only single bonds between its carbon atoms
unsat = at least one double bond between its carbon atoms
what type of reaction takes place when a triglyceride is formed
condensation reaction
what is the name of the bond that forms between a fatty acid and glycerol to form triglyceride
ester bond
how is an ester bond formed between a fatty acid and glycerol
a hydroxyl group from glycerol and a hydrogen atom from the fatty acid are removed to form a molecule of water and forming an ester bond between glycerol and the fatty acid, hence, a triglyceride is formed
what is the difference in unsaturated and saturated fatty acids in terms of their complement of hydrogen atoms
sat = has its full complement of hydrogens as there are no C=C double bonds in its hydrocarbon tail whereas unsat does not have its full complement of hydrogens as there is at least one C=C double bond in its hydrocarbon tail
Compare the melting point of an unsaturated and saturated fatty acid and why
saturated = higher
unsat = lower
as sat has its full complement of hydrogen atoms
What is the state of saturated and unsaturated fatty acids at room temperature
sat = solid
unsat = liquid
What does a high intake of saturated fats lead to in relation to cardiac health
high intake of saturated fats = increased risk of heart disease
why do lipid molecules store more chemical potential energy than carbohydrates
there are more C-H and C-C bonds in lipids than in carbohydrates
define what a respiratory substrate is
any molecule used to release energy to be used to create ATP
How do animals get energy from a respiratory substrate?
oxidation
what do phospholipids consist of
glycerol, fatty acid and phosphate ion
hydrophobic tails (fatty acids)
hydrophilic head (phosphate ion)
State the 2 key differences between the structure of a triglyceride and a phospholipid
triglyceride has 3 fatty acid tails and has glycerol as its head
phospholipid has 2 fatty acid tails and has glycerol and phosphate as its head
