Test your basic knowledge |

Food Chemistry

Instructions:

Answer 50 questions in 15 minutes.
If you are not ready to take this test, you can study here.
Match each statement with the correct term.
Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.

1. A chlorophyll molecule reacting with magnesium exhibits what shade of green?
Phenylketonuria
Fat Oxidation
Bright green
Cis

2. What is the protein efficiency ratio (PER) of casein?
2.5
Primary-amino acid sequence. Secondary-alpha-helix - beta sheet. Tertiary-one complete protein chain with cross bonds linking it together. Quaternary-four separate protein chains assembled as one.
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
20 carbons and 4 double bonds

3. Name 3 physical agents capable of denaturing proteins.
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
The speed of a molecule is proportional to the surrounding voltage gradient.
20 carbons and 4 double bonds
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.

4. When heated ammonium bicarbonate decomposes to form what end products?
.05 M HCL
Ammonia - Water - Carbon Dioxide
Primary-amino acid sequence. Secondary-alpha-helix - beta sheet. Tertiary-one complete protein chain with cross bonds linking it together. Quaternary-four separate protein chains assembled as one.
Sodium bicarbonate generates CO2

5. What are two common reducing agents that break disulfide bonds in proteins?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
.05 M HCL
HPLC has higher pressure than FPLC
RNA transcribed to DNA

6. What effect would the addition of sodium bicarbonate have to chocolate?
Glycosides of anthocyanidins
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Pectin Esterase

7. An emulsifier with a high hydrophilic-lipophilic balance (HLB) value would promote which type of emulsion: oil in water or water in oil?
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Oil in Water
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
A concentrate of microfibrillar proteins of fish muscle.

8. Match the number of carbon atoms with the common name of these saturated fatty acids. Carbon #: 4:0 10:0 - 12:0 -14:0 - 16:0 - 18:0Common Name: Myristic - Butyric - Capric - Lauric - Stearic - Palmitic
Gliadins and Glutenins
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Monosodium Glutamate
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)

9. What enzyme is most responsible for browning bananas?
Lipase
Water
Polyphenol Oxidase
Monosodium Glutamate

10. What name is given to the small circular DNA molecules that carry genetic information independently of the main bacterial chromosome?
Plasmids
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Chitin
Primary butyric acid also caproic acid.

11. Which of these foods is not appropriate to this list? A) Salami B) Yogurt C) Orange Juice D) Beer
Acetoin
Acetoin
Osmosis
Orange Juice

12. What charge will a protein have when the pH of its solution is below at - and above its pKa?
Onions ( or leeks)
pH below positive charge; pH at no charge; pH above negative charge
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Troponins and Tropomyosin

13. What happens to chlorophyll on heating?
D: None of the above
Pheophytin forms
Emulsification
RNA transcribed to DNA

14. How many carbon atoms and how many double bonds are there in arachidonic acid?
Capsaicin
20 carbons and 4 double bonds
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Water

15. What compounds oxidize to form brown color in fruits and vegetables?
Yes
RNA transcribed to DNA
Polyphenols
.05 M HCL

16. What are the limiting amino acids in corn - potato - and green peas?
Pectins
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Primary-amino acid sequence. Secondary-alpha-helix - beta sheet. Tertiary-one complete protein chain with cross bonds linking it together. Quaternary-four separate protein chains assembled as one.

17. Name the two components that comprise the relaxing factor in muscle fibers.
Yes
20 carbons and 4 double bonds
Troponins and Tropomyosin
Chitin

18. What is the chemical nature of anthocyanins?
14
Pectin Esterase
Monosodium Glutamate
Glycosides of anthocyanidins

19. What is the enzyme responsible for browning in apples and lettuce?
Polyphenol Oxidase
Initiation - Propagation - and Termination
Negative log of the hydrogen concentration (mol/l).
Polyphenoloxidase

20. Peptide bond formation results in the formation of what secondary compound?
Water
1 - 3 - 7-trimethylxanthine
RNA transcribed to DNA
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.

21. During freezing What are the two stages in the crystallization process?
Polyphenol Oxidase
V=IR and P=VI or I x I x are
Daminozide
Nucleation or crystal formation and crystal growth.

22. Alar is the trade name for what chemical compound?
Browning of freshly cut surfaces of fruits and vegetables.
No
Daminozide
pH below positive charge; pH at no charge; pH above negative charge

23. What is the major color compound in tomatoes?
Lycopenes
Fat Oxidation
Speed of Light
Cis

24. What is the chemical nature of anthocyanins?
Glycosides of anthocyanidins
Whole Milk
Daminozide
Fatty Acid and Alcohol

25. At what pH is benzoic acid most effective?
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
.05
pH 3-5
Pectin methyl esterase or galacturonase

26. What is Ohm's Law and What is Power Equation?
Egg white proteins - the globin part of hemoglobin - bovine serum albumin - gelatin - whey proteins - casein micelles - B-casein - wheat proteins - soy proteins - and some protein hydrolyzates.
Pectin Esterase - Polygalacturonase - Pectin Layase
Lysine - Arginine - and Histidine
V=IR and P=VI or I x I x are

27. Food additive that could be used to prevent cocoa particles from settling in chocolate milk
Lycopenes
Pectin methylesterase & polygalacturonase
The speed of a molecule is proportional to the surrounding voltage gradient.
Carrageenan

28. Waxes are composed of what two basic chemical entities?
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Fructose
Gliadins and Glutenins
Fatty Acid (Ester linked) to Fatty Alcohol

29. What are the three main steps in the autooxidation of lipids?
Non-protein nitrogen
D: None of the above
Water
Initiation - Propagation - Termination

30. Name 3 reasons it is advantageous to obtain enzymes from microorganisms.

31. What does Reichert-Meissert Number measure?
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Yellow
Fatty Acid (Ester linked) to Fatty Alcohol
Primary butyric acid also caproic acid.

32. Define molarity molality - and normality.
Pectin methyl esterase or galacturonase
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
NaCl (it dissociated to a 2M solution)
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.

33. What does the acronym NPN stand for?
Non-protein nitrogen
HLB (hydrophilic-lipophilic balance); a low value (3-6) promotes water in oil emulsions and a high value (8-18) promotes oil in water emulsions.
They are natural - nontoxic substances - generally catalyze without unwanted side-effects - active under very mild conditions of temperature and pH - active at low concentrations - rate of reaction can be controlled - can be inactivated after reactio
Anthocyanins

34. What is the acid present in fish oil?
2.5
NaCl (it dissociated to a 2M solution)
A concentrate of microfibrillar proteins of fish muscle.
Arachidonic Acid

35. Name two enzymes that are involved in softening fruits.
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Pectin Esterase - Polygalacturonase - Pectin Layase
Emulsoids
45% - 52% - 90%

36. Name two reasons why fats are hydrogenated.
Fat Oxidation
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Polyphenol Oxidase
Milk

37. Name 2 heat stable enzymes in food that are important to the quality of aseptic products.
Pectin methylesterase & polygalacturonase
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Daminozide
Two aldehydes

38. How many carbon atoms and how many double bonds are there in arachidonic acid?
Primary-amino acid sequence. Secondary-alpha-helix - beta sheet. Tertiary-one complete protein chain with cross bonds linking it together. Quaternary-four separate protein chains assembled as one.
V=IR and P=VI or I x I x are
Pectin methyl esterase or galacturonase
20 carbons and 4 double bonds

39. In genetics What is conjugation?
Acetoin
DNA transferred by cell to cell contact (bacterial sex).
Lipase
HPLC has higher pressure than FPLC

40. Name three non-nutritive sweeteners approved for use in USA?
Thickener in foods
Lipase
They are natural - nontoxic substances - generally catalyze without unwanted side-effects - active under very mild conditions of temperature and pH - active at low concentrations - rate of reaction can be controlled - can be inactivated after reactio
Acsulfame-K - Saccharin - Cyclamate - Aspartame

41. Name 3 physical agents capable of denaturing proteins.
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Whole Milk
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
45% - 52% - 90%

42. How do sodium chloride and sucrose affect foam stability?
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Polyphenoloxidase
Sodium chloride reduces foam stability and sucrose improves foam stability.
Linoleic Acid

43. How does HPLC differ from FPLC?
HPLC has higher pressure than FPLC
Thamautin
Thamautin
Thermus Aqauticus

44. Peptide bond formation results in the formation of what secondary compound?
Capsaicin
Water
Glycosides of anthocyanidins
Lycopenes

45. Name three factors useful in controlling enzyme activity.
Pheophytia does not have magnesium in porphyrin ring.
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Initiation - Propagation - Termination
Two aldehydes

46. Name three compounds capable of poisoning the catalyst during commercial hydrogenation.
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Chitin
1 - 3 - 7-trimethylxanthine
Initiation - Propagation - and Termination

47. Contains the lowest content of water
Whole Milk
Egg white proteins - the globin part of hemoglobin - bovine serum albumin - gelatin - whey proteins - casein micelles - B-casein - wheat proteins - soy proteins - and some protein hydrolyzates.
Plasmids
Initiation - Propagation - and Termination

48. Name 5 proteins with good foaming properties.
Egg white proteins - the globin part of hemoglobin - bovine serum albumin - gelatin - whey proteins - casein micelles - B-casein - wheat proteins - soy proteins - and some protein hydrolyzates.
Four
2.5
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents

49. What is the Peroxide Value a measure of?
Fat Oxidation
Sweet - Salty - Sour - and Bitter
Nucleation or crystal formation and crystal growth.
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.

50. What does the 'c' stand for in the equation E=mc2?
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Bitter
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Speed of Light