lipids Flashcards
name two groups of lipids
fats and oils
physical difference between fats and oils
fats are solids at room temp and oils are liquids
what chemicals do all lipids contain
carbon
oxygen
hydrogen
what do lipids contain less of compared to carbs
oxygen
what two organic chemicals are fats and oils made of
fatty acids and glycerol
what are fatty acids and glycerol combined with
ester bonds
glycerol chemical formula
C3H8O3
chemical structure of all fatty acids
long hydrocarbon chain
a pleated backbone of carbon atoms with hydrogen atoms
and a carboxyl group
in what ways do fatty acids differ
length of the carbon chain can differ
-fatty acid many be saturated or unsaturated
structure of saturated fatty acids
each carbon atom is joined to the next one to it by a single covalent bond
eg stearic acid
structure of unsaturated fatty acids
the carbon chains have one or more double covalent bond in them
monosaturated fatty acid
one double bond
polyunsaturated fatty acid
one or more double bond
eg linoleic acid
why is linoelic acid important in diets
because we cant make it from other chemicals
what is a fat or oil a result of
when glycerol combined with one two or three fatty acids to make monoglyceride diglyceride or triglyceride
what happens when glycerol bonds with a fatty acid
a bond is formed in a condensation reaction between the carboxyl group of a fatty acid and one of the hydroxyl group
how does this result in a ester bond
a molecule of water is removed and an ester bond is made
what is an ester bond condensation reaction called
esterification
how many atoms of oxygen are there in a triglyceride molecule
6 atoms
what happens when lipids are oxidised in respiration
bonds are broken are carbon dioxide and water are the last products.
-this reaction can be used to derive lots of ATP
why are lipids usefull
because they store 3 times the amount of energy as carbs do
why is lipids being hydrophobic important
key for waterproofing organisms
use of oils in waterproofing
they are hydrophobic so protect organisms outer surface area
why are lipids good insulators
a fatty sheath insulates your nerves so electrical impulses go faster called myelin
why do lipids have a low density and its importance
lipids being insoluble in water only
means they dont interfere with osmotic potential and water bases reactions
what ions are present in the cytoplasm of every cell
inorganic phosphate ions
PO43-
how are phospholipids formed
one of the hydroxyl groups of glycerol undergoes esterification with a phosphate group instead with a fatty acid and forms said thing
property of fatty chains of phospholipids
the fatty acid chains are neutral and insoluble
property of the phosphate group
it has a slight negative charge and is soluble in water so both parts of the molecule behave very differently
what part of the PL is hydrophillic
the polar phosphate group
what happens of molecules are tightly packed together
they form a monolayer of tightly packed atoms
micelles
spherical aggregate of molecules in water with hydrophobic areas in the middle and hydrophillic areas outside
bi layer
a double layer of closely packed atoms or molecules
unit membrane
a bilayer structure formed by phospholipids in an aqueous enviornment with the hydrophobic tails in the middle and hydrophillic heads on the outside
contrast unsaturated and saturated fatty acids
saturated=
-only single bonds
-straight chain molecules have many contact points
-higher melting point
-found in animals fats
unsaturated=
-double carbon bonds
-kinked molecules fewer contact points
-lower melting point
-found in plant oils
structure of tryglycerdes to their function
high energy mass ratio= high calorific value from oxidation
insoluble chain= protection and waterproofing
-slow conductor of heat=insulation
less dense than water=buoyancy of aquatic animals
describe function and structure of phospholipids
amphipathic=glycerol backbone attached to 2 hydrophobic fatty acid tails and hydrophillic phosphate group head
forms bilayer= component of membranes
tails can spray outwards=waterproofing
bond only between carbs
hydrogen bonds
bonds only between lipids
ester bonds
bonds between lipids and carbs
covalent bonds
