Unit 2 Flashcards
How are esters formed
A condensation reaction between an alcohol and a carboxylate acid
What is the reaction creating waters called
Esterification
Condensation
Finish the reaction
Alkanol + alkanoic acid —–>
Ester + water
For which compounds are the H20 taken from in esterification
H from alkanol
OH from alkanoic acid
What is the name of an esters functional group
Ester group
Ester linkage
What is the ending to the name of an ester
Oate
Describe where the name of an ester comes from
First part comes from the name of the alcohol
The second part comes from the name of the carboxylic acid
Which to compounds create methyl butanoate
Methanol and butanoic acid
Describe some of the properties of an ester
Strong sweet smelling
What are esters used for
Fragrances
Flavourings
Solvents
Are esters polar or non polar
They are not very polar
Can ester dissolve in water
No
Are the bp of esters high or low
Low
Are esters organic
Yes
Which two functional groups do alcohols and carboxylic acid join by to make an ester
Hydroxyl group of the alcohol and the carboxyl group of the acid
What is a condensation reaction
A reaction which two reactant molecules join with the elimination of a small molecule which is usually, but not always, water
Is condensation reversible
Yes
What catalyst can be added to esterification
Concentrated sulphuric acid
Why is concentrated sulphuric acid a good catalyst for an esterification reaction
It provides hydrogen ions and absorbs the water formed in the reaction and so encourages more alcohol and carboxylic acid to react
What is the process which esters are broken down
Hydrolysis
What catalyst can be used to hydrolyse esterification
Sodium hydroxide + heat
What is a hydrolysis reaction
A reaction where a molecule reacts with water and breaks down into smaller molecules
Edible fats and oils are ………. occurring compounds
Naturally
Name the tree different sources of fats and oils
Animal
Vegetable
Marine
Edible fats and oils are esters
True or false
True
How are fats and oils made
Condensation reactions between the alcohol glycerol and carboxylic acids fatty acids
What is the name of a compound with three hydroxyl groups
A triol
What is the systematic name for glycerol
Propane-1,2,3-triol
What happens to the name of an alcohol when it contains two or more hydroxyl groups
The parent alkane name is used in full (including the -e)
What are fatty acids
Straight chain carboxylic acids
What is an unsaturated compound
Compounds that contain at least one C=C
Fatty acids can only be saturated true or false
False
How many fatty acids will glycerol condense with
3
What’s an ester formed from glycerol called
A glyceride
What are the esters in fats and oils called
Triglycerides
Which decolourises bromine quicker fats or oils
Oils
What does a fast reaction with bromine indicate
A degree of unsaturation
What states are fats and oil usually at room temperature
Oils are usually liquid and fats are usually solid
Why do oils have a lowering mp than fats
They have more c=c which distorts their shape and therefore molecules cannot pack closely together and so LDF between oil molecules are weaker
What are the uses of fats to our bodies
Concentrated source of energy which is more a long term energy source
Transport and storage of fat soluble vitamins
Supply the body with essential fatty acids
Where are proteins found
In all living cells
What are proteins used for in the body
Major structural materials
Enzymes
Hormones
(Maintenance and regulation of life processes)
What are proteins made of
Amino acids
How many amino acids are there
20
What elements do amino acids contain
Hydrogen
Nitrogen
Carbon
Oxygen
What is the amino group
NH3
What two functional groups do amino acids contain
Amino group
Carboxyl group
What is a carboxyl group
COOH
What is the name of the reaction in which proteins are made from amino acids
Condensation
How do amino acids link together
The carboxyl group of one amino acid molecule and the amino group on the neighbouring amino acid molecule join together with the elimination of water
What is the amide/peptide link
I C=O I N-H I
What is the name of the molecule when three amino acids are condensed together
Tripeptide
What is the name of the molecule when a large number of amino acids condense
Polypeptide
What is the full name of the reaction forming proteins
Condensation polymerisation
What happens to proteins during digestion
They are broken down into amino acids
How are proteins broken down
React with water and undergo hydrolysis
Plants cannot synthesise all the amino acids that they need
True or false
False
What are essential amino acids
Amino acids which cannot be synthesised by animals
How do animals obtain essential amino acids
By hydrolysing the plant or animal proteins that we eat
During digestion where do the hydrolysed proteins go?
The amino acids pass into our blood stream and are carried to various sites in our bodies where they reassemble into specific proteins that we need
What percentage roughly of amino acids are essential amino acids
50%
Where in our bodies can flavours be detected
Tongue and nose
What are humans basic tastes
Sweet Sour Bitter Salty Savoury
How does the nose detect flavourings
Smells and aromas when gaseous molecules from volatile molecules trigger receptors in the nose
What does the volatility of a compound depend on
The strength of the intermolecular forces
If intermolecular forces are weak the molecule will be more volatile
True or false
True
Describe the bp of a very volatile compound
Very low
What flavour is limonene responsible for
Oranges
The presence of hydroxyl groups suggest what type of bonding
Hydrogen bonding
Does presence of a hydroxyl group indicate polarity
Yes
The presence of functional groups suggests the presence of what attractions
Permanent dipole- permanent dipole
What volatility will compounds that are hydrogen bonded have
Less volatile