1.3 Lipids Flashcards
What are lipids, describe them and give examples
Molecules made of carbon, hydrogen and oxygen, only soluble in organic solvents like alcohol, insoluble in water
Triglycerides and phospholipids
What are the functions of a lipid and some features
Protection - subcutaneous (underneath skin) fat to protect organs
Thermal insulation - adipose tissue
Cell membrane structure - phospholipid bilayer and cholesterol
Waterproofing - leaf cuticles, skin/fur/feathers
Source of metabolic water - from Rs of water
Buoyancy - less dense than water
Compact - take less storage, insoluble - osmotically inert, high energy yield - twice energy from fat than carbs
Give 2 examples of simple lipids
Glycerol and fatty acids
Give two examples of compound lipids
Glycerol and fatty acids
WITH GROUP/MOLECULE/COMPOUND
What is the chemical formula of glycerol and general formula of fatty acids
Glycerol - C3H8O3
Fatty acids - CH3(CH2)nCOOH
How are triglycerides formed
Glycerol and 3 fatty acids joined by ester bonds formed in condensation reactions
What are the differences between saturated and unsaturated fatty acids
Saturated = no c=c double bond in hydrocarbon tail, therefore has full complement of hydrogens, higher melting point, solid at room temperature
Unsaturated = at least one c=c double bond in hydrocarbon tail, doesn’t have full complement of hydrogens, lower melting point, liquid at room temperature
What is a respiratory substrate
Any molecule used to release energy to be used to create ATP
How are lipids a respiratory substrate
Oxidised to break down and release energy. Gives much more energy than carbohydrates as there are much more C-H and C-C bonds in lipids
What are the 3 components of phospholipids
Glycerol, fatty acid and phosphate ion
What are the differences in structure between triglycerides and phospholipids
Tri = glycerol head and 3 tails
Pho = glycerol and phosphate head and 2 tails
