Food Chemistry

The secondary structure of many proteins includes

helical regions. The type of chemical bond responsible

for maintaining this shape is the:

• hydrogen bonds

• ion–dipole bonds

• ionic bonds

• covalent bonds.

Olive oil contains a high proportion of oils made from a

fatty acid called oleic acid. The formula of oleic acid is

C₁₈H₃₄O₂. How many carbon-to-carbon double covalent

bonds are in oleic acid?

• 0

• 1

• 2

• 3

When a protein such as insulin is formed, the

condensation reaction that occurs involves:

• a carboxyl functional group and an amino functional

  group

• two hydroxyl functional groups

• a hydroxyl functional group and a carboxyl

  functional group

• a hydroxyl functional group and an amino functional

  group.

Tags

NGSS.HS-LS1-1

What will be the molar mass of a tripeptide

formed from the condensation of the amino acids

phenylalanine (M = 165 g mol⁻¹), isoleucine (M =

131 g mol⁻¹) and methionine (M = 149 g mol⁻¹)?

• 391 g mol⁻¹

• 409 g mol⁻¹

• 445 g mol⁻¹

• It will depend on the sequence in which they

  are connected.

When hydrochloric acid was added to some clear

uncooked egg white in a test tube, a white gelatinous

precipitate formed. When the mixture was boiled

gently, the precipitate slowly dissolved. Which of the

following lists the likely changes in the contents of the

test tube?

• Protein --acid added--> denatured and coagulated protein --

  heat--> free amino acids

• Protein --acid added--> free amino acids --heat--> carbon

  dioxide and water

• Glucose --acid added--> starch --heat--> glucose

• Free amino acids --acid added--> denatured and

  coagulated protein --heat--> free amino acids

Tags

NGSS.HS-PS1-2

NGSS.HS-PS1-4

NGSS.HS-PS1-5

The linkages by which monosaccharides are joined to

form disaccharides and polysaccharides are called:

• carbohydrate links

• peptide links

• ester links

• glycosidic links.

The polysaccharides starch, cellulose and glycogen

have significantly different properties primarily

because:

• each is formed from a different monosaccharide

  monomer

• the monosaccharide monomer from which they are

  formed is linked together in different ways

• they are composed of different amounts of glucose

  and fructose

• each is produced by a different type of organism.

A vitamin is:

• an organic compound (or group), required in

  small quantities and typically only obtainable from

  the diet

• any essential nutrient that cannot be synthesized by

  the body

• any essential source of energy for the body

• a chemical that does not occur in nature but that

  improves health when consumed.

Artificial sweeteners, such as aspartame, are perceived

to have which of the following dietary advantages over

natural sugars?

• They have a much lower energy content than

  sugars.

• They have antioxidant properties in addition to their

  sweetness.

• They have similar energy content to sugar but

  their higher sweetness means smaller amounts

  are required.

• They have a much longer shelf life and can be

  obtained in much higher purity.

An essential fatty acid is one that:

• is necessary for health but cannot be synthesized by

  the body

• is necessary for the proper function of an enzyme in

  the body

• cannot be obtained from food and must be

  synthesised in the body

• is needed by all living things for good health.