Carboxylic acids contain which functional group?
Carboxyl functional group
Carboxyl functional group has the structure?
Carboxylic acids react with bases to form?
An ester can be identified by?
The ester group (RCOOR)Name ending in -yl -oate
First part of ester name (-yl) comes from?
Alcohol used to make it
Second part of ester name (-oate) comes from?
The carboxylic acid
Esters have a characteristic?
Sweet' fruity smell
Uses of esters
Esters are formed by?
A condensation reaction between a carboxylic acid and an alcohol
The ester link is formed by?
The reaction of a carboxyl group and a hydroxyl group
What is a condensation reaction?
One where molecules join together with the elimination of a samll molecule (normally water)
Esters can be hydrolysed to?
Produce a carboxylic acid and an alcohol
What is a hydrolysis reaction?
When a molecule reacts with water to give smaller molecules
Fats and oils are a concentrated source of?
Fats and oils are essential for?
The transport and storage of fat-soluble vitamins in the body
Fats and oils are?
Fats and oils ae formed from?
The condensation of glycerol and three carboxylic acid molecules
Glycerol is also known as?
Carboxylic acids used to form fats and oils are known as?
Fatty acids are?
Saturated or unsaturated straight-chain carboxylic acids' usually with long chains of carbon atoms
The lower melting points of oils compared to those of fats is related to?
The high degree of unsaturation of oil molecules
The lower melting points of oils are a result of?
The effect that the shapes of the molecules have on close packing and thus the strength of the van der Waals' forces
Oils can be converted to fats by?
Hydrogenation of oils leads to a decrease in?
The number of carbon-carbon double bons
Hydrogenation of oils leads to an increase in?
The melting point of the oil
The major structural materials of animal tissue
Proteins are involved in
The maintenance and regulation of life processes
Proteins which act as biological catalysts
Within proteins the long-chain molecules may be?
Twisted to form spiralsFolded into sheetsWound round to form other complex shapes
Proteins can be?
Fibrous or Globular
Protein chains are held in shape by?
Intermolecular bonding between the side chains of constituent amino acids
If temperature increases or pH changes beyond a critical level the shape of the enzyme molecule is?
Irreversibly altered though the peptide links remain intact
If the active site of the enzyme has chained shape it is said to be?
Amino acids are ?
The building blocks from which proteins are formed.
Amino acids contain both?
An amino group (NH2)Carboxyl Group (COOH)
Amino acids used to make proteins are all?
α-amino acids have?
Tje carboxyl group and amino group attached to the same carbon
An essentail amino acid is?
One which cannot be made in our body so must be supplied by our diet
Proteins are made of many?
Amino acids linked together by condensation reactions.
In condensation reactions between amino acids?
The amino group on one amino acid and the carboxyl group on a neighbouring amino acid join together eliminating water
The link which forms between two amino acids is?
An amide link (CONH)Also called peptide link
Proteins which fulfil different roles in the body are formed by?
Linking differing sequences of amino acids together
During digestion' enzyme hydrolysis of dietary proteins produces?
Amino acids present in a protein can be identified by?
Hydrolysing the protein (Uaing acid) and then using chromatography.Application of known amino acids to the chromatogram alongside hydrolysed protein allows amino acids to be identified
Aldehydes and ketones both contain?
The carbonyl functional group (CO)
Aldehydes have the carbonyl group at?
The end of a chain
Ketones have the carbonyl group?
Not at the end of a chain
Aldehydes can be identified by?
Its '-al' end
Ketones can be identified by their?
Aldehydes that onlay contain C-C single bonds are called?
Ketones that only contain C-C single bonds are called?
Aldehydes can be oxidised to?
Indicators used to differentiate between an aldehyde and ketone
Acidified dichromateBenedict's solutionTollens' reagent
Acidified dichromate turns from?
Orange to green
Benedict's solution turns from?
Blue solution to a red precipitate
Tollen's regeant turns from?
A colourless solution to a silver mirror
The majority of what we describe as flavour comes from?
Odour identified by nasal cells
Flavour molecules are wafted?
Up the mouth
Flavours of foods are due to the presence of?
Volatile organic molecules
By looking at functional groups present in flavour molecules it is possible to suggest?
Wether they are likely to be water soluble or oil soluble
Looking at the size of the molecule and functional groups present allows predictions to be made about?
The boiling point and hence the volatility of flavour molecules
When proteins are heated?
The intermolecular bonds are broken allowing proteins to change shape
Changes to the shape of proteins alters?
The texture of foods
Alcohols can be identified fom?
The hydroxyl functional group (-OH)'-ol' name ending
Alcohols that only contain C-C double bonds are celled?
Hydrogen bonds found in alcohols explain?
Solubility in waterHigher boiling point
In alcohols hydrogen bonding increases with?
An increase in the number of hydroxyl groups
Triols are more viscous than?
diols and monols
When drawing the full structural formula of an alcohol the hydroxyl group must be shown?
-O-H and Not -OH
An alcohol may be (Depending on structure)?
Primary' secondary or tertiary
Primary alcohols (Oxidation)
Oxidised to an aldehyde then to a carboxylic acid
Secondary alcohols (Oxidation)
Oxidised to ketones
Tertiary alcohols (Oxidation)
Cannot be oxidised
Hot copper(II) oxide or acidified dichromate solutions can be used to oxidise?
Primary and secondary alcohols
When copper(II) oxide oxidisises an alcohol it turns from?
Black to brown
Carboxylic acids (Reduction)
First to aldehyde then to primary alcohol
Oxidation results in (O:H ratio)
Increase in oxygen to hydrogen ratio
Reduction causes (O:H ratio)
Oxygen reacts with edible oils giving the food a?
Molecules which prevents oxidation of edible oils
Ion-electron equations can be written for the oxidation of?
The alkaline hydrolysis of fats and oils forms?
Water-soluble ionic salts called soaps
Structure of soap ion
Long covalent tail (hydrophobic)Ionic Carboxylate head (Negatively charged and hydrophilic)
Detergents are similar to?
Soaps but have different hydrophilic heads
Detergents are particularly useful in?
Hard water areas
During cleaning using soaps and detergents?
Hydrophobic tails dissolve in oil/greaseHydrophilic heads face outwardsBall-like structure forms Repulsion between charges results in emulsion being formed and dirt-released
An emulsion contains?
Small droplets of one liquid dispersed in another liquid
Emulsions in food are mixtures of?
Oil and water
Emulsion: To prevent oil and water components seperating into layers?
An emulsifier is added
Emuslifiers for use in food are commonly made by?
Reacting edible oils with glycerol to formrm molecules where one or two fatty acids are linked to a glycerol backbone
Fatty acid chains are (Emulsions)?
Essential Oils are?
Concentrated extracts of volatile 'non-water soluble aroma compounds from plants
Essential Oils are mixtures of?
Essential oils are generally extracted by?
Steam distillation or solvent extraction
Essential oils are widely used in?
Perfumes' cosmetics' cleaning products and flavourings
Terpenes are key components in?
Most essential oils
Unsaturated compounds formed from units of isoprene
The basic molecular formulae of terpenes are?
Multiples of C5H8 (C5H8)n
Isoprene units may be linked together to form?
Chains or rings
The isoprene unit is one of?
Nature's most common building blocks
Terpenes are components in a wide variety of?
Fruit and floral flavours and aromas
Terpenes can be oxidised within plants to produce?
Some of the compounds responsible for the distinctive aroma of spices
Ultraviolet radiation is?
A high-energy form of light' present in sunlight
Exposure to UV light can result in?
Molecules gaining sufficient energy for bonds to be broken. (Process responsible for sunburn)
UV light reaching the skin
When UV light breaks bonds what are formed?
What is homolytic fission?
When a bond splits evenly' with each atom getting one of the shared pair of electrons to give two free radicals
Free readicals have an unpaired electron so?
Are highly reactive
Steps of a free radical chain reaction?
Many cosmetic products contain?
Free radical scavengers
Free radical scavengers are?
Moleciules which can react with free radicals to form stable molecules and prevent chain reactions
Free radical scavengers are added to?
Food productsPlasticsCosmetic products
Examples of natural free radical scavengers
MelatoninVitamin EBeta Carotene