Molecules (lipids)- topic 1 Flashcards
what are the elements that lipids contain?
-carbon
-hydrogen
-oxygen
what makes lipids and carbohydrates different if they consist of the same elements?
-the proportion of hydrogen relative to oxygen is much greater than carbohydrates where the ratio is 2:1
are lipids polymers?
-they do form large molecules known as macromolecules however they are not polymers
what substances are lipids soluble in?
-they are not soluble in water (hydrophobic) but are soluble in organic solvents such as ethanol
what are the 4 types of lipids?
-triglycerides
-phospholipids
-waxes
-steroids
how are triglycerides formed?
-through a combination of glycerol and fatty acids
-each triglyceride contains one glycerol molecule which is joined with three fatty acid molecules
what are fatty acids and how are they formed ?
-organic acids that form long hydrocarbon tails linked to a carboxyl group at one end of the chain
-different fatty acids have different lengths of hydrocarbons
what is a carboxyl group?
-a group linked to the end of a fatty acid molecule
-COOH
how can different triglycerides be formed and why is this?
-there are over 70 types of fatty acids which can be the same or a range of different types in one triglyceride
in triglycerides where does the condensation reaction occur ?
-it occurs between the OH hydroxyl group of the glycerol and the COOH carboxyl group of each fatty acid
following a condensation reaction what is the bond called between the fatty acids and the glycerol?
-an ester bond holds the two in place
how does the hydrolysis of a triglyceride occur? when does this occur ?
-it uses three molecules of water and produces three fatty acids and one molecule of glycerol
-happens during lipid digestion
what are saturated fatty acids and why are they called this?
-they contain the maximum amount of hydrogen molecules along the length of hydrocarbon chain i.e. each carbon atom is linked with two hydrogen atoms
-all the carbons are saturated
how are the carbon atoms linked in saturated fatty acids?
-by single carbon to carbon bonds
how are the carbon atoms linked in unsaturated fatty acids?
-they have at least one carbon to carbon double bond (monounsaturated fatty acids) or contain more that one double bond (polyunsaturated fatty acids)