lipids Flashcards
1
Q
what are the two main lipid groups?
A
triglycerides and phospholipids
2
Q
how are triglycerides formed?
A
- condensation of one molecule of glycerol and three fatty acids (RCOOH)
- forms an ester book
- produces a water molecule
3
Q
how are phospholipids different to triglycerides?
A
one of the fatty acids of a triglyceride is substituted by a phosphate group
4
Q
properties of a triglyceride
A
- non-polar structure
- insoluable in water (hydrophobic fatty acid chains)
- long hydrocarbon chains
5
Q
function of a triglyceride
A
- stored in adipose tissue
- used as energy storage molecules during respiration
- fatty acid chains can be broken down to release chemical energy (lipolysis)
6
Q
properties of a phospholipid
A
polar, hydrophilic head
non- polar hydrophobic tails
7
Q
function of phospholipid
A
component of cell membranes, control what enters and leaves the cell
maintains stability of cell
8
Q
structure of phospholipid bilayer
A
- two layers of phospholipid molecules
- hydrophobic tails facing eachother, creating hydrophobic interior
- hydrophilic heads facing outwards, creating surrounding water-based environment
9
Q
function of phospholipid bilayer
A
- semi-permeable barrier
- allows small hydrophobic molecules to pass through
- excludes larger hydrophilic molecules
- helps maintain balance of ions in cell
10
Q
emulsion test for lipids
A
- add ethanol to sample
- shake vigorously
- if lipids present, cloudy white emulsion forms
11
Q
saturated fatty acids
A
contain a single bond and have a long carboxylic chain
12
Q
unsaturated fatty acids
A
- contain one or more double bond
- > 1 polyunsaturated bond
- < 1 monounsaturated bond
