1.2 - Lipids Flashcards
Fats and oils are made up of two organic chemicals
what are they?
fatty acids and glycerol
How do fatty acids and glycerol combine
Ester bonds
In which 2 ways do fatty acids differ
The length of the carbon chain can differ
The fatty acid can be saturated fatty acid or unsaturated fatty acid
What is a saturated fatty acid
A saturated fat is a type of fat in which the fatty acid chains have all single bonds
What is an unsaturated fatty acid
the carbon chains have one or more double covlanet bond in them
What is a monosaturated fatty acid
Had one double bond
What is a polyunstarurated fatty acid
Had more than one double bond
How does a fat or oil form
When glycerol combines with one,two or three fatty acids to form a diglyceride or triglysicide
What is esterfication
is the formation of ester bonds
How is Triglycerides formed
Triglycerides are formed by the condensation of one molecule of glycerol and three molecules of fatty acid.
A condensation reaction between glycerol and a fatty acid (R-COOH) forms an ester bond
When lipids are oxidised in respiration the bonds are broken down what is it broken down into
Carbon dioxide and water
When lipids are broken down and oxidised and their bonds are broken down what can this reaction be used to drive
The production of ATP
What is the diffrence between lipids and carbohydrates
Lipids such as triglyidicde store about 3x as much energy as the same mass of carbohyrdates
What is the pro of lipids being a a good insulator
A fatty sheath insulates your nerves so the eletrical impulse travels faster
Which lipid waterproofs the fur and feathers of mamals and birds
Oil
Why do animals want to be insulated
too avoid heat loss
Why can some animals float easily
Because lipids have very low density so the body fat of water mammals helps them float easily
What is a phospholipid
is a chemical in which glycerol bonds with two fatty acids and ignoric phosphate group
What ion is available in every cytoplasm
inorganic phospate ion
How is a phosphilid formed
sometimes one of the hydroxl groups of glycerol undergoes and esterfication reaction with a phosphate group
Instead of a fatty acid
Why are phosphilids important
becasue the lipid and phosphate parts of the molecule give it very diffrent properties
The phosphate head carries what?
a small negative charge
Is the phosphate head soluable or insoluable in water
soluable
What happens when the phosphilids come into contact with water? -Head
2 parts of the molecule act differently
The polar phosphate part is hydrophillic and dissolves readily into water
If the molecules are tightly packed when they enter the water they form a monlayer
With the hydrophillic heads in the water
What is a monolayer
is a single closely packed layer of atoms or molecules
What are micelles
A spherical aggerate of molecules in water with hydrophobic areas in the middle and hydrophillic ares outside
What happens in a micelle
All the hydrophliic heads point outwards and all the hydrophobic tails are inside
What is a bilayer
is a double layer of closely packed atoms or molecules
What is a unit membrane
is a bi-layer structure formed by phoslplhilds in a aqueous environment with the hydrophobic tails in the middle and the hydrophilic heads outside
So what happens in the end when phosphiolds are in the water
With water on each side the phosphilid molecules form a bilayer with the hydrophillic heads pointing into the water protecting the hydrophobic tails in the middle
What happens when the phosphilids come into contact with water? (2)- Tails
2 parts of the molecule act differently
The lipid tails are hydrophobic so do not dissolve in water
If the molecules are tightly packed when they enter the water they form a monlayer
and the hydrophobic tails in the air or clusters called micelles
Draw the structure of phsoplipid
Check the book
How is a posholipid formed
one of the hydroxyl groups of glycerol goes a esterification reaction with a phosphate group instead of an fatty acid
What is a poshop[hlipoid
a chemical in which glycerol bonds with two fatty acids and an ingornic phosphate group
Why are lipids good at at energy storage
lipids contain many carbon hydrogen bonds and little oxygen
when they are oxideised in respiration the bondsa re broken and co2 and water are the prodcuts
this reaction can be sued to drive the production of ATP
Why are Lipids are good insulators
they have thick fat layers that trap air inside
