Unit 2 Flashcards
The negatively-charged ball-like structures…
repel each other and the oil or grease is kept suspended in the water
free radicals are…
atoms or molecules that are highly reactive due to the presence of unpaired electrons
the negatively charged hydrophilic heads…
remain in the surrounding water
the solubility, boiling point and volatility of a compound can be predicted by considering…
- O-H or N-H bonds, which implies hydrogen bonding
- molecular size which would affect london dispersion forces
- polarity of solute and solvents
Edible fats and edible oils are…
esters from the condensation of glycerol and three carboxylic acid molecules
the carboxylic acids are known as ‘fatty acids’
carboxylic acids can react with…
bases
proteins are the major…
structural materials of animal tissue and are also involved in the maintenance and regulation of life processes. Enzymes are proteins which act as BIOLOGICAL CATALYSTS
Amino acids are…
relatively small molecules which all contain an amino group -NH2 and -COOH
The link which forms between two amino acids is known as a…
peptide link/amide link
Essential amino acids are…
amino acids that our body cannot make. It is essential that these amino acids are present in our diet
when proteins are heated…
The intermolecular bonds are broken which changes shape of the protein (denature)
PS. it causes texture in food to change when cooked
oxidation is an…
increase in the oxygen to hydrogen ratio
Reduction is an…
decrease in the oxygen to hydrogen ratio
fats and oils are…
- a concentrated source of energy
- essential for the transport and storage of fat-soluble vitamins in the body
the equation for the breakdown of an ester by water is…
Ester + Water <=> alcohol + carboxylic acid
a “reversible reaction”
An ester link is…
-COO-
When soap is used in hard water…
scum, an insoluble precipitate is formed
hydrolysis produces…
3 fatty acid molecules and 1 glycerol molecule
an emulsion contains…
small droplets of one liquid dispersed in another liquid
hot copper oxide or acidified dichromate solution can be used to oxidise…
- primary alcohols to aldehydes then to carboxylic acid
- secondary alcohols to ketones
in a hydrolysis reaction…
a molecule reacts with water to break down into smaller molecules
alcohols can be classified as…
primary/secondary and tertiary
OH groups make alcohols…
polar and this allows hydrogen bonding to take place
in a condensation reaction…
two molecules are joined together with the elimination of a small molecule
esters are formed by…
a condensation reaction between an alcohol and a carboxylic acid
esters are used as…
flavourings and fragrances. They are also used as solvents for non-polar compounds that do not dissolve in water