Lipids Flashcards
(14 cards)
What are lipids?
Lipids are a wide group of organic molecules that are part of the cell membrane (so not polymers or macromolecules) and are all hydrophobic (insoluble in water).
Are membranes polymers? Why/why not?
No, because they are not connected, only closely attracted to one another.
What are fats made of?
Fats are made of glycerol and three fatty acids.
What are fats connected by?
Ester Linkage
What is ester linkage, and what does it do?
Ester linkage connects fats together by a dehydration reaction that removes water. There are three in fats and are composed of a carbonyl group and a single bonded oxygen.
What is triacylglycerol and what does it do?
Store energy in the body, fat molecule formed of glycerol and three fatty acids.
What is fat used for?
Fat is used mostly for energy storage in animals. Stores more fat than starches (in plants) because animals require movement.
Characteristics of saturated fats
Saturated fats have no double bonds and are straight in shape. They are solid at room temperature due to efficient packing of straight molecules.
Characteristics of unsaturated fat
Have at least one double bond (cis/trans) so there is a bend in their shape. Double bond prevents tight packing of molecules and unsaturated fats are liquid at room temperature.
Characteristics of steroids
Made of four fused rings with different chemical groups attached, usually as pentagons or hexagons. Found in membranes and sex hormones for ex.
What are phospholipids made of?
They are made up of 2 fatty acids that compose the hydrophobic tail, and the hydrophilic head is made of glycerol, a phosphate group and an attached molecule.
What are phospholipids?
They are the building blocks of cell membranes that have heads and tails that naturally assemble into bilayers, with the hydrophilic head on the outside and hydrophobic tails on the inside (to avoid contact with water).
What are the three main groups of lipids?
Fats, phospholipids and steroids
What are glycolipids?
They are lipids with a sugar group attached to the extracellular side.
