Module 2 Section 2 LIPIDS Flashcards
What are elements are lipids Made up of
Carbon Hydrogen oxygen
What is the structure of a triglyceride
Glycerol head and 3 fatty acid tails
What are the fatty acids long tails made of
Hydrocarbons
Are fatty acid tails hydrophilic or hydrophobic
Hydrophobic (they repeal water)
What is the basic structure of a fatty acid tail
O=C-R -> “R” varies
/
OH
What happens in triglyceride synthesis
They are synthesised by the formation of an ester bond between each fatty acid and the glycerol molecule
What is the process of triglyceride synthesis called
Esterification
What type of reaction is Esterification
Condensation
How do triglycerides break down
When ester bonds are broken
What type of reaction is breaking up a triglyceride
Hydrolysis
What’s the difference between saturated and unsaturated fatty acids
Saturated fatty acids have no double bonds between the carbon atoms, they are saturated with hydrogen
Unsaturated fatty acids have at least one double bond between carbon atoms
What is the structural noticeable difference between saturated and unsaturated fatty acids
Unsaturated fatty acids have a kink caused by the double bond
What is the structure of a phospholipid
They have a glycerol head, a phosphate group and two fatty acid chains
What type of molecules are phospholipids made up of
Macromolecules
What part of a phospholipid is hydrophilic
The phosphate group
What part of a phospholipid is hydrophobic
The fatty acid tails
Triglycerides are macromolecules. What are macromolecules?
Complex molecules with a relatively large molecular mass
What is the function of triglycerides
Storage (energy in plants and animals, energy and carbon in some bacteria)
How do the properties of triglycerides make them suitable for their functions
They have long hydrocarbon tails that contain lots of chemical energy, which is released when they are broken down, they can store about twice as much energy per gram as carbohydrates
They are insoluble so don’t allow water to enter cells by osmosis which would make them swell and reduce the amount of possible storage space
What is the function of a phospholipid
Make up the phospholipid bilayer in cell membranes. Cell membranes control what enters and leaves a cell
How do the properties of phospholipids make them suitable for their functions
Their heads are hydrophilic and tails are hydrophobic so they form a double layer with their heads facing out to the water on either side and protecting the tails inside
The centre of the bilayer is hydrophobic so water soluble substances can’t pass easily- the membrane acts as a barrier to those substances
What is the function of cholesterol
In eukaryotic cells they strengthen the cell membrane by interacting with the phospholipid bilayer
How do the properties of cholesterols make them suitable for their functions
It’s small in size and flat in shape
- allowing it to fit in between the phospholipid molecules in the membrane
- then they bind to the hydrophobic tails of the phospholipid causing them to pack more closely together
- making it less fluid and more rigid
