1.2 - Lipids

Question 1

Fats and oils are made up of two organic chemicals

what are they?

Answer 1

fatty acids and glycerol

Question 2

How do fatty acids and glycerol combine

Answer 2

Ester bonds

Question 3

In which 2 ways do fatty acids differ

Answer 3

The length of the carbon chain can differ

The fatty acid can be saturated fatty acid or unsaturated fatty acid

Question 4

What is a saturated fatty acid

Answer 4

A saturated fat is a type of fat in which the fatty acid chains have all single bonds

Question 5

What is an unsaturated fatty acid

Answer 5

the carbon chains have one or more double covlanet bond in them

Question 6

What is a monosaturated fatty acid

Answer 6

Had one double bond

Question 7

What is a polyunstarurated fatty acid

Answer 7

Had more than one double bond

Question 8

How does a fat or oil form

Answer 8

When glycerol combines with one,two or three fatty acids to form a diglyceride or triglysicide

Question 9

What is esterfication

Answer 9

is the formation of ester bonds

Question 10

How is Triglycerides formed

Answer 10

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

Question 11

When lipids are oxidised in respiration the bonds are broken down what is it broken down into

Answer 11

Carbon dioxide and water

Question 12

When lipids are broken down and oxidised and their bonds are broken down what can this reaction be used to drive

Answer 12

The production of ATP

Question 13

What is the diffrence between lipids and carbohydrates

Answer 13

Lipids such as triglyidicde store about 3x as much energy as the same mass of carbohyrdates

Question 14

What is the pro of lipids being a a good insulator

Answer 14

A fatty sheath insulates your nerves so the eletrical impulse travels faster

Question 15

Which lipid waterproofs the fur and feathers of mamals and birds

Answer 15

Oil

Question 16

Why do animals want to be insulated

Answer 16

too avoid heat loss

Question 17

Why can some animals float easily

Answer 17

Because lipids have very low density so the body fat of water mammals helps them float easily

Question 18

What is a phospholipid

Answer 18

is a chemical in which glycerol bonds with two fatty acids and ignoric phosphate group

Question 19

What ion is available in every cytoplasm

Answer 19

inorganic phospate ion

Question 20

How is a phosphilid formed

Answer 20

sometimes one of the hydroxl groups of glycerol undergoes and esterfication reaction with a phosphate group
Instead of a fatty acid

Question 21

Why are phosphilids important

Answer 21

becasue the lipid and phosphate parts of the molecule give it very diffrent properties

Question 22

The phosphate head carries what?

Answer 22

a small negative charge

Question 23

Is the phosphate head soluable or insoluable in water

Answer 23

soluable

Question 24

What happens when the phosphilids come into contact with water? -Head

Answer 24

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

Question 25

What is a monolayer

Answer 25

is a single closely packed layer of atoms or molecules

Question 26

What are micelles

Answer 26

A spherical aggerate of molecules in water with hydrophobic areas in the middle and hydrophillic ares outside

Question 27

What happens in a micelle

Answer 27

All the hydrophliic heads point outwards and all the hydrophobic tails are inside

Question 28

What is a bilayer

Answer 28

is a double layer of closely packed atoms or molecules

Question 29

What is a unit membrane

Answer 29

is a bi-layer structure formed by phoslplhilds in a aqueous environment with the hydrophobic tails in the middle and the hydrophilic heads outside

Question 30

So what happens in the end when phosphiolds are in the water

Answer 30

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

Question 31

What happens when the phosphilids come into contact with water? (2)- Tails

Answer 31

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

Question 32

Draw the structure of phsoplipid

Answer 32

Check the book

Question 33

How is a posholipid formed

Answer 33

one of the hydroxyl groups of glycerol goes a esterification reaction with a phosphate group instead of an fatty acid

Question 34

What is a poshop[hlipoid

Answer 34

a chemical in which glycerol bonds with two fatty acids and an ingornic phosphate group

Question 35

Why are lipids good at at energy storage

Answer 35

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

Question 36

Why are Lipids are good insulators

Answer 36

they have thick fat layers that trap air inside