Lipids Flashcards
What elements make up lipid molecules
Carbon, hydrogen, oxygen, ( ( and phosphorous for phosphate in phospholipids):
What are the 2 main type of lipids
oils → liquid at room temp
Fats → solid at room temp
Are lipids polar
Non-polar and hydrophobic due to fatty acid tail so immiscible / doesn’t dissolve in water because its hydrophilic but does in non-polar the other lipids + some organic solvents
Function of lipids
Energy source + storage→ 2 x more than carbs because they have more c-h bonds which is where the chemical energy is stored + stored in adipose cells → protects delicate organs from physical damage → oxidation of . Triglycendes produces metabolic water during chemical reactions which helps fluid balance so excesswater and heat are dissipated -
Lipid functions pts 2
Phospholipids = important component of all biological membranes → waxes and oils can waterproof leaves ( cuticles) reducing water loss →thermal insulators reducing body heat loss and electrical insulators for nerve cells → some hormones like steroids are lipids
Define saturated fatty acids
All carbon atoms joined by single bond no double Carbon bond → max number of no hydrogen atoms per carbon atom → long straight chains with high melting point → animal fats
Unsaturated fatty acid
At least one double Carbon bond so don’t have max theoretical hydrogen atoms bonded → plants + form oils → polyunsaturated fats= healthier
Structure of triglycerides
One glycerol and 3 fatty acids → after condensation polymerisation reaction 3 ester bonds between OH of glycerol and COOH of fatty acid formed and 3 water molecules removed
Structural formula of glycerol → has to be drawn
→ general formula of fatty acid
C3H803
CH3(CH2)nCOOH
What are fatty acids
Long molecules with hydrophilic polar end and hydrophobic non-polar tail
Components of phospholipids
Glycerol, two fatty acids and one phosphate group
Product of lipid hydrolysis
Glycerol and fatty acids
Why are lipids used instead of carbs for energy store in seeds and animals
Nearly 2 x higher yield of energy per gram
Why are triglycerides non-polar + there fore insoluble in water
Glycerol has hydrophilic polar OH ion + carboxylic group is also polar so hydrophilic group / create ester bond so now hydrophobic because fatty acidsuse hydrophobic → their hydrocarbon chain
What happens it person has high intake of saturated fats
Liver produces large amounts of low density (LDL) leading to plaque build up → atheromas in coronary artery restrict blood flow to heart muscle so cardiac muscle receives less glucose and oxygen, lead to c blood clots and atherosclerosis
