triglycerides Flashcards
what is a lipid
a group of substances which are soluble in alcohol rather than water.
what is a macromolecule
a large, organic molecule
what is a phospholipid
molecule consisting of glycerol, two fatty acids and a phosphate group
what is the role of cholestrol in the phospholipid membrane
binds to phospholipid fatty acid tails.
increasing packing of membrane
reducing fluidity of membrane
what elements are in a lipid
cho
describe the solubility of a lipid
not soluble in water because they arent polar
they are soluble in alcohol
what are the three most important lipids in living things
triglyceride
steroid
phospholipid
are lipids polymers
NO
instead they are macromolecules
-this was an exam question
describe triglyceride structure
glycerol
fatty acids
what is an essential fatty acid
a fatty acid which isnt synthesised in the body
needs to be ingested
describe the structure of a glycerol molecule
3 carbon atoms
three, free -OH groups
the rest are free hydrogen ions
describe the structure of a fatty acid
have a carboxyl group on one end attached to a hydrocarbon (CARBON atom chain, attached to multiple hydrogen ions)
why are fatty acids acidic
due to their free hydrogen ions
what is the difference between a saturated and unsaturated fatty acid
saturated- NOOOOO DOUBLE BOND BETWEEN CARBOM
Unsaturated- HAS A DOUBLE BOND.
describe how double carbon bonds impact structure of a hydrocarbon chain
gives it a kink where the double bond is
more fluid due to the kinks
and lower melting point if there are more unsaturated fatty acvids
what bond is used to bind glycerol and fatty acids
ester bond
what reaction creates an ester bond
condensation
where does the ester bind form between the glycerol a fatty acd
-COOH group on the fatty acid
and the -OH group on the carboxyl
what are the 5 functions of the triglyceride
energy source
energy store
insulation
buoyancy
protection
how are triglycerides energy source
can be broken down in respiration to release energy and generate ATP
the first step is to hydrolyse an ester bond.
both fatty acids can be broken down to carbon dioxide and water
what do triglycerides get broken down in respiration
co2 and water
how are triglycerides energy stores
because triglycerides when are insoluble in water, they can be stored without affecting the water potential of the cell
what releases more energy glucose or lipid
lipids release 2x more energy than glucose
how do lipids act as an insulator
e.g. lipids in nerve cells act as an electrical insulator
how do lipids act as a buoyancy agent
fat is less dense than water.
helps mammals float
how is a triglyceride a protection factor
humans have fat around organs, such as kidney to protect them from damage
compare glucose and lipids as energy storage
glucose
-large
- insoluble
- dont affect water potential of the cell
-1-4 glycosidic bonds
- easy to make and break to release glucose monomers
coiled and take up less space.
amylose, amylopectin- plants
glycogen/ starch in animals
lipids- fats have carbon-carbon hydrogen bonds
contain 2x more energy than glucose molecule
more energy can be stored in less space
insoluble in water
doesnt affect water potential
