CH3 lipids Flashcards
1
Q
What is the difference of fats and oils
A
Oils are liquid at room temperature and fats are solid
2
Q
Why are lipids insoluble
A
- non-polar
- electrons in the outer shell are more evenly distributed than in polar molecules
3
Q
What is a triglyceride
A
Three fatty acids (COOH) and one glycerol (OH)
4
Q
How is a triglyceride formed
A
- hydroxyl groups interact leading to formation of three ester bonds and three water molecules
- process is esterification (a condensation reaction)
5
Q
What is a saturated fatty acid chain
A
- no double bonds present
- straightchain so molecules pack close together
- solid at room temperature
6
Q
What is an unsaturated fatty acid chain
A
- double bonds present
- causes molecule to kink
- cannot pack closely together so are liquid at room temperature
7
Q
What is a phopshate group
A
- PO4, 3-
- soluble in water
8
Q
What is a phospholipid
A
- one fatty acid replaced by a phosphate group
- have a dual hydrophobic/hydrophilic nature
9
Q
How do phospholipids interact with water
A
- form a layer on surface of water with fatty acid tails sticking out
- form a bilayer with tails pointing towards centre of sheet
10
Q
What is a sterol
A
- steroid alcohol
- complex alcohol molecules based off four carbon ring structure with hydroxyl group at one end
- dual hydrophobic/hydrophilic nature
11
Q
What is cholesterol
A
- manufactured in liver and intestines
- stability and regulates fluidity of membranes
- becomes positioned between phospholipids with hydroxyl group at periphery of membrane
12
Q
Roles of lipids
A
- membrane formation
- hormone production
- electrical insulation
- thermal insulation
13
Q
How to test for lipids
A
Emulsion test
14
Q
How to carry out emulsion test
A
- mix sample with ethanol
- shake
- present: white emulsion forms as a layer on top
