Unit 2 - Nature's Chemistry Flashcards
What is the functional group for an ester
Ester link
What does an ester’s name end in
-yl -oate
How are esters made
Condensation or esterification reaction
What is the word equation for esterification
Alcohol + carboxylic acid ester + water
Why is a wet paper towel used in a condensation reaction
To catch any gases that escape from the reaction
What is the catalyst used in a condensation reaction
Concentrated sulphuric acid
What is used to heat the reactants during a condensation reaction
Hot water bath - since alcohol flammable
How can you tell if an ester has been produced
Oily layer and a sweet smell
Why is sodium hydroxide used in a condensation reaction
To neutralise the acid catalyst
What are some uses for esters
- fragrances
- flavourings
- nail polish
- solvents for car paint
What is hydrolysis
The breaking up of a substance using water
What are fats and oils example of
Esters
Why do we need fats and oils
Give our body energy
Is a fat saturated or unsaturated
Saturated (c-c singles bonds)
Why do fats have higher melting points than oils
Molecules pack closer together, stronger Van Der Waal forces between them, higher melting points
Will a fat decolourise bromine solution
No it is a saturated molecule
Is an oil saturated or unsaturated?
Unsaturated (c=c double bonds)
Will an oil decolourise bromine solution
Yes - unsaturated molecule
What happens when oils react with oxygen
Turns rancid
What is the chemical reaction used to produce fats and oils
Condensation/ esterification
What molecules are needed to make a fat/oil
Glycerol + 3 fatty acids
What is hydrogenation
The addition of hydrogen to an unsaturated molecule
How is an alkane produced
When an alkene is reacted with hydrogen in a hydrogenation reaction
What happens when an oil reacts with hydrogen
Turns into margarine (hardening)
What term is used to describe an amino acid that must be obtained from our diet
Essential amino acid
What type of link is found in proteins
Amide/peptide link
What type of reaction is used to form proteins
Condensation
What are proteins made from
Amino acids
What produces amino acids during digestion
Enzyme hydrolysis of dietary proteins
What type of reaction is used to break down proteins to form amino acids
Hydrolysis
Between what elements in the protein do the bonds break between during hydrolysis
Carbon with double bonded oxygen and nitrogen
What are the two types of protein structure
Fibrous and globular
What is the structure of a fibrous protein
Polypeptide chains interwoven, held together by hydrogen bonds
What kind of properties do fibrous proteins have
Toughness, insolubility, resistance to changes in pH
What is the structure of globular proteins
Polypeptide chains are coiled together in spherical shapes
What happens to the structure of a protein when heated
Structure changes (eg heating an egg)
What happens to polarity and flammability as the carbon chain increases
Both decrease
Why does polarity and flammability decrease as the carbon chain increases?
There is less hydrogen bonding between molecules
If an alcohol ends in -triol how many hydroxyl groups are present
Three hydroxyl groups
What happens to the properties of a molecule as there is an increase in hydrogen bonding
- higher boiling points
- increased viscosity
- increased solubility in water