Section 7 natural substances

Question 1

What is the ester link functional group

Answer 1

COOC or C=OOC

Question 2

Naming esters rules

Answer 2

Alcohol at the front - which turns into a branch name
Carboxylic acid at the end - which turns into salt.

Ethanol + Propanoic acid <—-> ethyl propanoate + water

Question 3

How are esters formed in esterification

Answer 3

The hydroxyl group of the alcohol breaks off and the hydrogen on the carboxyl group breaks off, and the oxygen of the carboxyl group binds with the carbon of the alcohol.

Question 4

What can esters be used for

Answer 4

Flavourings, fragrances and solvents

Question 5

Condensation reaction definition

Answer 5

A reaction where two functional groups bond together with the elimination of a small molecule, such as water, an example of this is esterification.

Question 6

Esterification

Answer 6

A condensation reaction forming an ester from an alcohol and carboxylic acid, bonding together the carboxyl and hydroxyl functional group to form an ester link, eliminating and releasing a water molecule.

Question 7

Esterification experiment

Answer 7

An equal quantity of alcohol and carboxylic acid is used with a sulphuric acid catalyst.
A hot water bath is used to heat up because reactants are flammable.
Cold paper towel is used to cool down evaporating reactants (condenser)

Question 8

How do you break up an ester

Answer 8

Hydrolysis

Question 9

Hydrolysis

Answer 9

Where a molecule is broken down into smaller molecules by reacting it with water, this breaks apart a functional group into two different functional groups as well.

Question 10

What happens in hydrolysis
Of esters

Answer 10

The ester breaks apart at the bond between the single carbon oxygen bond where the carboxylic acid will be formed on the ester link, and hydrogen will be added to the carboxylic acid from water, a hydroxyl group will be added to the alcohol from water.

Question 11

Hydrolysis reaction
Esters

Answer 11

Ester + water —-> alcohol + carboxylic acid

Question 12

Why is it not suitable to use a Bunsen when heating alcohols and carboxylic acids

Answer 12

Flammable

Question 13

Hydrolysis reaction definition - esters

Answer 13

Where an ester is broken down into an alcohol and carboxylic acid by water, by the ester link functional group being broken down into a carboxyl and hydroxyl functional group.

Question 14

What are edible fats and oils

Answer 14

Esters formed by the condensation reaction of glycerol - propane -1,2,3, - triol and three carboxylic acids called fatty acids.

Question 14

Fats and oils uses

Answer 14

Concentrated source of energy and essential for the transport and storage of fat soluble vitamins.

Question 15

Saturated fats and oils

Answer 15

Fats and oils that only contain single bonds between the carbons

Question 16

Unsaturated fats and oils

Answer 16

Fats and oils that contains a carbon to carbon double or triple bond.

Question 17

Saturated fatty acids general formula

Answer 17

CnH2n+1COOH

Question 18

Unsaturated fatty acids formula

Answer 18

CnH2n+1COOH
Minus 2 hydrogens for each carbon to carbon double bond.

Question 19

What do saturated fatty acids form from condensation reactions with glycerol

Answer 19

Saturated fats

Question 20

What do unsaturated fatty acids form with condensation reactions with glycerol

Answer 20

Unsaturated oils.

Question 21

Rules for fats and oils saturation

Answer 21

Saturated = fats
Unsaturated = oils
This is a rule of thumb not a constant

Question 22

Why do fats have a higher melting and boiling point than oils.

Answer 22

Because fats are saturated, and oils are unsaturated, this means that the fatty acids in fats are packed much closer together than the oils fatty acids, therefore the molecules are much closer together in fats than in oils and the van der waals forces are stronger, increasing the heat energy required for these fats to melt.

Question 23

How do you compare the degree of unsaturation

Answer 23

The more unsaturated the oil is the more bromine water can be added.

Question 24

Proteins functions

Answer 24

Structure
Maintenance and regulation of life processes

Question 25

Enzymes definition

Answer 25

Proteins which act as biological catalysts.

Question 26

Amino acids definition

Answer 26

The building blocks from which proteins are formed, containing an amino and carboxyl functional group.

Question 27

Essential amino acids

Answer 27

Amino acids that must be acquired from the diet, due to the body not being able to make the amino acids for protein synthesis.

Question 28

Examples of structural proteins

Answer 28

Muscle
Skin
Hair

Question 29

Examples of proteins for maintenance and regulation

Answer 29

Enzymes
Hormones
Haemoglobin

Question 30

Different structures of proteins

Answer 30

Sheets -linear
Spirals - non linear

Question 31

Intermolecular bonding in a protein

Answer 31

Hydrogen bonding

Question 32

Denaturing

Answer 32

Where the hydrogen bonding between a protein breaks down and causes the protein to change shape, due to high temperature or extreme pH

Question 33

Denaturing effect on food

Answer 33

Texture of food changes when heated.

Question 34

How are proteins formed

Answer 34

By the condensation reaction of amino acids, removing water molecules and forming peptide or amide links.

Question 35

Amide/peptide link

Answer 35

C=ONH

Question 36

Digestion of proteins

Answer 36

Where proteins undergo hydrolysis, to break apart the protein at the amide links and produce amino acids.

Question 37

Where does an peptide/amide link form

Answer 37

Between the amino and carboxyl group