1.1: Lipids Flashcards
What is the bond in a lipid called?
Ester bond.
What is a triglyceride made of?
One molecule of glycerol and three fatty acids joined by ester bonds formed in condensation reactions
How are ester bonds formed?
In a condensation reaction.
What is a wax?
A lipid that melts above 45°.
What are the properties of a wax?
They are typically waterproof.
What do lipids contain?
Contain carbon, hydrogen and oxygen. Though, they have much less oxygen than carbohydrates.
What are the characteristics of lipids?
Non-polar and insoluble in water.
What are lipids soluble in?
Organic solvents such as alcohols.
What are saturated fatty acids?
Single bonds between carbons atoms.
What are unsaturated fatty acids?
Double bonds between carbon atoms, they have a ‘kink’.
What are the roles of lipids?
Make phospholipids in cell membranes. Myelin sheath around nerve cells for electrical insulation.
Lipids create a what sheath?
Myelin.
What are the charactistics of triglycerides?
Energy reserves, thermal insulation, protection and metabolic water.
What are the groups of lipids?
Triglycerides (fat and oils), phospholipids and waxes.
In a triglyceride, the glyceride molecule is __ and but the fatty acids ___ ?
glyceride molecule is always the same, but the fatty acids vary.
The condensation reaction occurs between?
The carboxyl group (COOH) of the fatty acid and the hydroxyl group (OH) of the glycerol.
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Why are triglycerides hydrophobic?
There are no spare oxygen molecules to form hydrogen bonds with, making them insoluble.
A phospholipid is polar. Why?
Fatty acids repel water, but phosphate molecules attract water. Molecules that have two poles that behave differently are said to be polar.
