lipids Flashcards
what are the two types of lipids?
triglycerides
phospholipids
how are triglycerides formed?
a condensation reaction happens between one molecule of glycerol and three molecules of fatty acid.
what is the bond formed in triglycerides?
an ester bond
what is the standard formula for fatty acids?
RCOOH
where are phospholipids found?
in the cell membrane (phospholipid bilayer)
what are phospholipids made of?
hydrophilic phosphate heads and hydrophobic fatty acid tails.
are the hydrophilic heads polar or non - polar?
polar - so they can form bonds with water
what are saturated lipids?
lipids that don’t contain carbon-carbon double bonds and are those found in animal fats.
what are unsaturated lipids?
they’re found in plants and contain carbon-carbon double bonds - this means that the molecule is able to bend.
unsaturated fats cannot pack together as tightly and so are liquid at room temp.
what are the similarities and differences between triglycerides and phospholipids?
- both have one glycerol molecule
- triglycerides have 3 fatty acids whereas phospholipids have 2 fatty acids plus a phosphate group
explain how the properties of triglycerides are related to their structure.
has hydrophobic fatty acids so its insoluble in water so t doesn’t affect cell water potential.
what is the function of phospholipids, describe how the properties of phospholipids relate to their structure.
function - to form a bilayer in the cell membrane, allowing diffusion of lipid-soluble substances and restricting water-soluble substances.
- has hydrophilic phosphate heads which attract to water.
- has hydrophobic fatty acid tails that repel by water.
describe the test for lipids.
add ethanol, shake, add water.
positive result = white emulsion.
