Lipids Flashcards
What are lipids insoluble in
Water
What are lipids soluble in
Organic solvent
What elements do lipids contain
H C and O however may contain others
What are fatty acids
A long hydrocarbon chain with a carboxyl group at the end
How many types of fatty acids are there
70 types
What is the general formula for fatty acids
CnH2nO2
What are triglycerides
Natural fats and oils
What do triglycerides consist of
A glycerol molecule and 3 fatty acids
What reaction forms a triglyceride
A condensation reaction
Why are lipids useful for organisms
Excellent energy store for animals
low mass : energy so a large amount of energy in a small volume
Large and nonpolar- soluble in water with no effect on Water potential
What bond joins fatty acids to glycerol
Ester bond
What are the types of fatty acids
saturated and unsaturated
What does a saturated fatty acid mean
No double bond between carbon atoms in the hydrocarbon chain
What does a unsaturated fatty acid mean
More than one double bond between carbon atoms in the hydrocarbon chain
Molecule is able to bend
What does a phospholipid consist of
a glycerol molecule joined to two fatty acids and a phosphate molecule
What are some uses for phospholipids
Polar so when they are in aqueous environment a bilayer can form and they are the main component of cell membranes
Create a hydrophobic core in the phospholipid bilayer
hydrophobic head means the phospholipid can be used to
From glycolipids allowing the CSM to recognise cells
What type of head does a phospholipid have
Hydrophylic head
What type of tail does a phospholipid have
Hydrophobic tail
What is glycerol
An alcohol molecule with a formula C3H8O3
How does a phospholipid differ from a triglyceride
A phospholipid has a phosphate group and 2 fatty acids
A triglyceride has 3 fatty acids
How would you test for a lipid
Add ethanol to food molecules, shake then add water
If a white milky substance is shown, lipids are present if its colourless they are not
What result shows a positive ethanol test
White milky water
What are the two types of unsaturated tryglycerides
Monosaturated-1 double bond between carbon molecules
Polysaturated-many double bonds between carbon molecules
What type of reaction forms an ester bond
Condensation reaction
What are the functions of triglycerides
Energy storage- when TGs are oxidised bonds break releasing energy used to produce ATP
Insulation - part of the myelin sheath which surround nerve fibres which increases speed of nerve impulse transmission
Buoyancy- low density of fat tissue allows the ability for animals to float more easily
Protection- helps protect organs in mammals from the risk of damage due to the adipose tissue in mammals
Name the group represented by COOH
Carboxyl
Describe the formation of triglycerides
One glycerol and 3 fatty acids joined by an ester bond in a condensation reaction by removing 3 water molecules
Describe how an ester bond is formed in a phospholipid molecule
In a condensation reaction due to a loss of water. The bond is formed between the glycerol and fatty acid
