Lipids Flashcards
What elements are lipids made of?
Hydrogen
Carbon
Oxygen
Lipids are hydrophobic. What does this mean ?
The molecule does not mix with water. The oil and water molecules repel each other
What are the 3 types of lipids?
Phospholipids
Steroids
Triglycerides
What is the E shaped molecule called?
Why is it called this?
Triglycerides
Triglycerides are made of three fatty acids attached to a glycerine backbone
How many types of fatty acids are there?
70+
What makes the different fatty acids actually different?
Different “R” groups/ variant “R” groups
What is meant by a saturated Fatty acid?
Where all the carbons on the carbon chain are connected together by single bonds and have the highest number of hydrogens connected to each of these carbons.
What is meant by an unsaturated hydrocarbon?
Where the hydrocarbon has a double bond between carbons in the hydrocarbon tails
How does the double bond affect the shape of the chain and the state of the fat at room temp?
The hydrocarbon tail has a kink in it. At room temperature the fat is a liquid.
What does monounsaturated mean?
There is only one double bond in the hydrocarbon tail
What does polyunsaturated mean?
There are multiple double bonds in the hydrocarbon chain
How do triglycerides form?
Through a condensation/ esterification reaction
This happens 3 times, 1 for each hydrocarbon tail.
A water molecule is removed every time one hydrocarbon is attached so in total 3 water molecules are removed
What bonds are formed during triglyceride formation?
Ester bonds
What has a higher boiling point unsaturated or saturated triglycerides?
Saturated triglycerides
Where do saturated triglycerides derived from ?
Animals
Where are unsaturated triglycerides derived from?
Plants
Why are triglycerides a great source of energy?
They contain twice the amount of energy as carbohydrates in the same weight.
Why are lipids good storage molecules?
A lot of energy can be stored in a small volume
Low mass:energy ratio
Why is having lipids not being able to dissolve in water an advantage?
They are large and non polar. This means that they do not affect osmosis when being stored
What is the role of lipids in waterproofing?
Lipids are insoluble in water so they repel water making things like leaves waterproof
Why are lipids food for thermal insulation?
Fats are slow conductors of heat . Reduce heat loss
Why are lipids good for protection?
Lipids separate the organs from one another to help protect them from damage
What are phospholipids made up of?
2 fatty acids tails and 1 phosphate and a glycine backbone
What makes phospholipids have a hydrophobic region and a water soluble region?
The phosphate makes the phospholipid water soluble
The fatty acid tails make the phospholipid hydrophobic
Where are phospholipids usually found?
Cell membranes
What is the test for lipids
The emulsion test Add 2cm3 of sample and 5cm3 ethanol. Shake Add 5cm3 of water and shake again If it emulsifiers it has lipids in in. If it remains clear there is no lipids
