FSHN 214 Exam 4 study Questions and
correct Answers
What are the two functions of protein in food? - ANSW-to provide nutrients(essential amino acids) and
give functionalities to food
What is the structure of an amino acid? - ANSW-amine group, carboxyl group, side chain(R group) and
asymmetrical carbon
What is the nature of the binding between 2 amino acids? - ANSW-peptide bond- a covalent bond
What is the primary - secondary - tertiary and quaternary structures of a protein? - ANSW-Primary-
sequence of amino acids
Secondary- formation of alpha helix and beta sheets, hydrogen bonds between amine group and
carboxyl group
Tertiary- 3D folding, hydrophobic interaction- hydrogen bonds, interaction between side chains of amino
acids, disulfide bonds between cysteine, orientation of hydrophobic residues inside
Quaternary- association of different subunits of tertiary structures
True or false: fibrous proteins are soluble? - ANSW-false- they are insoluble
What is the definition of a conjugated protein? Give one example - ANSW-a protein attached to another
macromolecule
ex- lipoprotein
What is the hydration property of a protein and what is the consequences on food? - ANSW-ability to
dissolve and attract water
induces the ability to form gels
What is the definition of denaturation and coagulation? - ANSW-Denaturation- disruption of the protein
structure - loss of functions (partial or total)
Coagulation- Clotting or precipitation of protein in a liquid into a semisolid compound
Give one example of food based on the protein denaturation - ANSW-egg
Give one example of enzymatic reaction occurring in food - ANSW-enzymatic browning
What is the amphoteric property of a protein - ANSW-when a protein can be acidic or basic depending
on pH
What is the isoelectric point of a protein? what is the impact on food? - ANSW-it is where the protein is
neutral and is least soluble
it can induce precipitation of protein at the isoelectric point- irreversible
What is the basic composition of milk? - ANSW-solids(12.6%)- including fat(30% of solids), nonfat(70% of
solids)- sugar(lactose) and protein(casein and whey), minerals
, water (87.4%)
What is the molecular organization of milk? - ANSW-Combination of:a true solution- minerals, vitamins
and lactose dissolve in aqueous phase
colloidal dispersion- fat globules and protein
What is the major lipid in milk? - ANSW-triglycerides (98%)
rich is saturated fatty acids- 70-75%
rich in short chain fatty acids- responsible for development of rancidity in dairy products
What is the fat organization in milk? - ANSW-fat globule- multilayered membrane
monolayer of phospholipid
bilayer of phospholipid
contains proteins and conjugated proteins
What are the two types of protein found in milk? - ANSW-casein and whey
How can we separate the two proteins in milk? - ANSW-get pH to 4.6(isoelectric point)
Which of the milk protein is globular? - ANSW-whey
Which protein is insoluble? - ANSW-casein
Which protein is associated to calcium? - ANSW-casein
How is organized the casein in milk? - ANSW-micellar organization
hydrophobic interaction between a-s1, a-s2, and beta- unordered aggregation
What are the 4 types of casein? - ANSW-a-s1, a-s2, beta, kappa
Which type of casein is not sensitive to calcium? - ANSW-kappa(k)
What is the objective of pasteurization? - ANSW-to reduce microbial deterioration- destroy pathogens
reduce enzymatic activity
What are the two forms of pasteurization? - ANSW-low temp long time- 62.5C 30 min
high temp short time- 71.5C 15 sec
What is the objective and consequences of homogenization? - ANSW-high pressure equipment create
pressure
large fat globules are reduced to small ones
consequences- prevents fat creaming, decreases sensitivity to oxidation, develops flavor and milk
mouthfeel
True or false: Enzymatic coagulation is used to prepare yogurt - ANSW-false- enzymatic coagulation is
used to prepare CHEESE
correct Answers
What are the two functions of protein in food? - ANSW-to provide nutrients(essential amino acids) and
give functionalities to food
What is the structure of an amino acid? - ANSW-amine group, carboxyl group, side chain(R group) and
asymmetrical carbon
What is the nature of the binding between 2 amino acids? - ANSW-peptide bond- a covalent bond
What is the primary - secondary - tertiary and quaternary structures of a protein? - ANSW-Primary-
sequence of amino acids
Secondary- formation of alpha helix and beta sheets, hydrogen bonds between amine group and
carboxyl group
Tertiary- 3D folding, hydrophobic interaction- hydrogen bonds, interaction between side chains of amino
acids, disulfide bonds between cysteine, orientation of hydrophobic residues inside
Quaternary- association of different subunits of tertiary structures
True or false: fibrous proteins are soluble? - ANSW-false- they are insoluble
What is the definition of a conjugated protein? Give one example - ANSW-a protein attached to another
macromolecule
ex- lipoprotein
What is the hydration property of a protein and what is the consequences on food? - ANSW-ability to
dissolve and attract water
induces the ability to form gels
What is the definition of denaturation and coagulation? - ANSW-Denaturation- disruption of the protein
structure - loss of functions (partial or total)
Coagulation- Clotting or precipitation of protein in a liquid into a semisolid compound
Give one example of food based on the protein denaturation - ANSW-egg
Give one example of enzymatic reaction occurring in food - ANSW-enzymatic browning
What is the amphoteric property of a protein - ANSW-when a protein can be acidic or basic depending
on pH
What is the isoelectric point of a protein? what is the impact on food? - ANSW-it is where the protein is
neutral and is least soluble
it can induce precipitation of protein at the isoelectric point- irreversible
What is the basic composition of milk? - ANSW-solids(12.6%)- including fat(30% of solids), nonfat(70% of
solids)- sugar(lactose) and protein(casein and whey), minerals
, water (87.4%)
What is the molecular organization of milk? - ANSW-Combination of:a true solution- minerals, vitamins
and lactose dissolve in aqueous phase
colloidal dispersion- fat globules and protein
What is the major lipid in milk? - ANSW-triglycerides (98%)
rich is saturated fatty acids- 70-75%
rich in short chain fatty acids- responsible for development of rancidity in dairy products
What is the fat organization in milk? - ANSW-fat globule- multilayered membrane
monolayer of phospholipid
bilayer of phospholipid
contains proteins and conjugated proteins
What are the two types of protein found in milk? - ANSW-casein and whey
How can we separate the two proteins in milk? - ANSW-get pH to 4.6(isoelectric point)
Which of the milk protein is globular? - ANSW-whey
Which protein is insoluble? - ANSW-casein
Which protein is associated to calcium? - ANSW-casein
How is organized the casein in milk? - ANSW-micellar organization
hydrophobic interaction between a-s1, a-s2, and beta- unordered aggregation
What are the 4 types of casein? - ANSW-a-s1, a-s2, beta, kappa
Which type of casein is not sensitive to calcium? - ANSW-kappa(k)
What is the objective of pasteurization? - ANSW-to reduce microbial deterioration- destroy pathogens
reduce enzymatic activity
What are the two forms of pasteurization? - ANSW-low temp long time- 62.5C 30 min
high temp short time- 71.5C 15 sec
What is the objective and consequences of homogenization? - ANSW-high pressure equipment create
pressure
large fat globules are reduced to small ones
consequences- prevents fat creaming, decreases sensitivity to oxidation, develops flavor and milk
mouthfeel
True or false: Enzymatic coagulation is used to prepare yogurt - ANSW-false- enzymatic coagulation is
used to prepare CHEESE
