Lipids 1 Flashcards
What are lipids?
Molecules that contain hydrocarbons and make up the building blocks of structures and function in a living cell
When are lipids soluble?
They are hydrophillic but are soluble in organic solution
Are lipids hydrophobic or hydrophillic?
Hydrophobic
Where can lipids be found?
Cell membranes
Adipose tissue
Blood lipoproteins
What are some functions of lipids?
Stored form of energy
Structural element of membreanes
Enzyme cofactors
Hormones
Vitamins A, D, E and K
Signalling molecules
What are the 5 lipid classes?
Fatty acids
Triacylglyderol
Phospholipids
Glycolipids
Steroids
What are the 2 forms of fatty acids?
Unsaturated (one or more double bonds)
Saturated (no double bonds)
How are fatty acids named?
By the number of carbons, number of double bonds and the position of the double bond
Give examples of lipid naming?
18: 0 - 18 carbons, no double bonds
18: 3 (9, 12, 15) - 18 carbons, 3 double bonds, double bonds between 9/10, 12/13 and 15/16
What are the 4 kinds of fatty acids in our diet?
Essential fatty acids (linoleic eg)
Good fats (high in polyunsaturated fats such as olive oil)
Bad fats (high in saturated fatty acids such as beef)
Very bad fats (trans fatty acids such as hard margarine)
What are saturated fats good for?
The nervous system
What are essential fatty acids?
Cannot be synthesised, need to be consumed in our diet
Why can essential fatty acids not be synthesised?
We cannot introduce double carbon bonds beyond carbon 9
What are omega-3 fatty acids derived from?
Linolenic acid (essential fatty acid)
What are omega-3 fatty acids good for, and omega-6?
Lowering blood cholesterol
What are triacylglycerols?
Esters of fatty acids and glycerol
What are triacylglycerols used for?
Storing energy and insulation
Are triacylglycerols water soluble?
No
What are phospholipids?
A lipid containing a phosphate group
How are phospholipids amphipathic?
They contain a hydrophillic head and a hydrophobic tail
Why are phospholipids often used in membranes?
They are amphipathic
What does amphipathic mean?
Has a hydrophillic and a hydrophobic component
What is the main site of lipid digestion?
Small intestine
Where does lipid digestion start?
In the mouth