Lipids 1 Flashcards
Where are the different places you can find lipids in the body?
Cell membranes, lipid droplets in adipose tissue, in blood lipoproteins
What are some of the biological functions of lipids?
Stored form of energy, structural element of membranes, enzyme cofactors, hormones, vitamins A,D,EK, signalling molecules
What are the different classes of lipids?
Fatty acids, triacylglycerol, phospholipids, glycolipid and steroids
When writing the structure of a fatty acid, what does the term 18:2(9,12) mean?
There are 18 carbons with two double bonds, occuring at carbon atoms 9 and 12
What are the essential fatty acids?
Linoleic and aplha - linolenic - must get these from plants
What are good fats?
High in polyunsaturated fatty acids e.g vegetable oil, sunflower oil and olive oil
What are the bad fats?
High in saturated fatty acids? e.g. stearic (beef)
What useful function do saturated fatty acids have?
Huge role in myelination of nerve fibres and hormone production
What are the really bad fats?
Trans fatty acids
How are these really bad fats made?
Hydrogenation of vegetable oils
Up to which point in a fatty acid chain can a human no longer produce a double bond?
9
What can be derived from linolenic acid?
Omega three fatty acids
What effect does omega 3 have?
lowers plasma cholesterol prevents atherosclerosis, lowers triacylglycerol
What is derived from linoleic acid?
Omega 6
What are the effects of fatty acid deficiency?
Growth retardation, reproductive failure, skin lesions, ADHD - more behavioural problems Depression
How would you describe the Ph and charge of an ester?
Neutral and uncharged
Describe the solubility of triacylglycerol
Insoluble in water
What is the main lipid component of adipose tissue?
Lipid droplets
What can triacylglycerol be used for?
Fuel and insulation
What is the main dietary lipid?
Triacylglycerol
What is the main site of lipid digestion?
Small intestine
Lipases are involved in lipid digestion, where are lipases made?
Pancreas
What effect does bile salts have?
Emulsification of lipids (breaks down fat globules into smaller droplets) - larger surface area for lipase to act on
Forms mixed micelles
What physical mechanism helps with protein digestion?
Peristalsis
What are bile salts derivatives of
Cholesterol