lipids and proteins Flashcards
What are lipids and
what are some of its properties and
what are the 2 types of lipids
- macromolecule containing Carbon, Hydrogen and Oxygen (lipids contain a lower proportion of oxygen unlike carbohydrates)
- Non polar and hydrophobic
2 types of lipids are
. triglycerides
. phospholipids
What are triglycerides
how are they created
They are non polar, hydrophobic molecules
they are made up of one glycerol and 3 fatty acids bonded via a condensation reaction creating ester bonds
3 water molecules will be produced
What is glycerol and why is it what it is
what is glycerol’s formula
It is an alcohol because it has a hydroxyl group (OH)
(C^3 H^8 O^3)
What do fatty acids contain
A methyl group at ne end of the hydrocarbon chain
the hydrocarbon chain can be 4 - 24 carbons long.
At the other end there is a carboxyl group (C double bond O then C single bond OH)
How can lipids vary
They can vary in
. Length of hydrocarbon chain
. Fatty acids being saturated or unsaturated
What is an unsaturated fatty acid and what are the 2 types of fatty acids
It has a double bond meaning it doesn’t contain the maximum amount of hydrogens it can
It can either be mono or poly-unsaturated
cis-fatty acids = When the H are on the same side of the double bond and can be metabolised
trans-fatty acids = H are on different sides and they cannot be metabolised
What is a saturated fatty acid
No double bonds (except in carboxyl group) and there is the maximum amount of hydrogens that can be held.
What is esterification and how does it happen
triglycerides are formed by esterification
- when a hydroxyl group on glycerol binds to the carboxyl group via condensation reaction on the fatty acid an ester bond is formed
A H from the hydroxyl group binds to OH on a carboxyl group it releases a water molecule
What is the main function of triglycerides
Energy storage - when long hydrocarbon chains with little oxygen are oxidised during respiration the bonds break releasing energy and produces ATP.
- triglycerides store more energy that carbohydrates and proteins
- they are hydrophobic so they don’t cause osmotic water uptake - more can be stored
What are the other functions of triglycerides
insulation - triglycerides are apart of myelin sheaths surrounding nerve fibres. Provides insulation that increases speed of transmission of nerve impulses
- against heat loss (adipose tissue layer underneath the skin acting as insulation)
buoyancy - Low density of fat tissues increase the ability of animals to float more easily
protection - protects organs (adipose tissues)
Why are triglycerides non polar
Because they are neutral
What is a phospholipid and what is its structure
A phospholipid is a glycerol molecule, a phosphate group and 2 fatty acid chains
-It has a negatively charged, polar head containing glycerol and a phosphate .The head is hydrophilic
- It has 2 fatty acids which are non polar connected via ester bonds. The tails are hydrophobic
What do phospholipids formed and why
Phospholipids form a monolayer of a bilayer when placed in water with there heads facing out toward the water and their tails facing out away from the water
What is the structure of the phospholipid bilayer
what can it be called
A hydrophobic core is formed. This acts as a barrier to water soluble molecules meaning they cannot pass through therefor facilitated diffusion is needed
The hydrophobic heads form H- bonds with water
The phospholipids aren’t attached
it can be referred to as the fluid mosaic model
What are proteins
Biological catalysts
polymer made up of amino acids
