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. What are two common reducing agents that break disulfide bonds in proteins?
Negative log of the hydrogen concentration (mol/l).
Erythorbic Acid
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Yes

2. Name two reasons why fats are hydrogenated.
Daminozide
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.

3. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
Acsulfame-K - Saccharin - Cyclamate - Aspartame
They act as catalysts - speeding the polymerization of acrylamide.
Oil in Water
Anomeric

4. What does Acid Degree Value measure and how is it measured?
Pheophytin forms
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Polyphenols
Tryptophan

5. Name three non-nutritive sweeteners approved for use in USA?
No
Primary butyric acid also caproic acid.
Lycopenes
Acsulfame-K - Saccharin - Cyclamate - Aspartame

6. What does the 'c' stand for in the equation E=mc2?
Phenophylin
Primary butyric acid also caproic acid.
Blue pigment in flowers
Speed of Light

7. What happens to a bottle of wine if before you bottle it you forget to put the stuff in it that prevents it from fermenting?
Primary butyric acid also caproic acid.
It explodes
14
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).

8. Name the two components that comprise the relaxing factor in muscle fibers.
Troponins and Tropomyosin
45% - 52% - 90%
Daminozide
Monosodium Glutamate

9. Alar is the trade name for what chemical compound?
Daminozide
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Fructose
Polyphenols

10. What is the major color compound in tomatoes?
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Primary butyric acid also caproic acid.
Lycopenes

11. What does the saponification value measure and how is it measured?
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
.05

12. What are two common reducing agents that break disulfide bonds in proteins?
Oil in Water
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Pectin methylesterase & polygalacturonase

13. What does the acronym NPN stand for?
Pheophytin forms
Non-protein nitrogen
Fructose
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.

14. What is the geometric configuration of double bonds in most natural fatty acids?
Oil in Water
Sweet - Salty - Sour - and Bitter
Thermus Aqauticus
Cis

15. Which two amino acids is the aspartame derived from?
Bitter
HPLC has higher pressure than FPLC
Anthocyanins
Aspartic Acid and Phenylalanine

16. What is surimi?
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
.05 M HCL
Monosodium Glutamate
A concentrate of microfibrillar proteins of fish muscle.

17. What does the iodine value measure and how is it measured?
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Bright green
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Phenylketonuria

18. Which will be coldest at its freezing point: 1M dispersion of amylose 1M solution of NaCl - distilled water - or 1M solution of sucrose?
Microorganisms are very versatile - MO's can be altered by mutations or genetic engineering to produce a greater quantity of enzyme or different enzymes - recovery of enzymes is often easy - readily available - high rate of growth and enzyme producti
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
NaCl (it dissociated to a 2M solution)
Pectin methylesterase & polygalacturonase

19. What metabolic disorder prevents conversion of phenulalanine to tyrosine by normal metabolic pathways?
Browning of freshly cut surfaces of fruits and vegetables.
Phenylketonuria
Milk
V=IR and P=VI or I x I x are

20. What charge will a protein have when the pH of its solution is below at - and above its pKa?
Anthocyanins
pH below positive charge; pH at no charge; pH above negative charge
Fructose
Speed of Light

21. What is the structural difference between chlorophyll and chlocophyllide?
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
ERH=100 x Aw
Chlocophyllide does not have a phytoltail
Water

22. Name three factors useful in controlling enzyme activity.
Fatty Acid (Ester linked) to Fatty Alcohol
Microorganisms are very versatile - MO's can be altered by mutations or genetic engineering to produce a greater quantity of enzyme or different enzymes - recovery of enzymes is often easy - readily available - high rate of growth and enzyme producti
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Water

23. What name is given to the small circular DNA molecules that carry genetic information independently of the main bacterial chromosome?
Linoleic Acid
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).
Cis

24. What are the only phenols approved for use in the microbiological preservation of foods?
Emulsification
Parabens
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Onions ( or leeks)

25. Name two non-enzymatic browning reactions.
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
DNA transferred by cell to cell contact (bacterial sex).
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Carmelization and Maillard

26. In what food is butyric acid typically found?
A concentrate of microfibrillar proteins of fish muscle.
D: None of the above
Milk
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.

27. Name the strongest biochemical bond and the weakest biochemical bond.
Fatty Acid and Alcohol
45% - 52% - 90%
1 - 3 - 7-trimethylxanthine
Covalent (strongest) and Hydrophobic (Weakest)

28. What are soluble polymers of anhydro-galacturonic acid and its esters called?
Yes
ERH=100 x Aw
Pectins
The speed of a molecule is proportional to the surrounding voltage gradient.

29. What metabolic end product does the Voges-Proskauer test detect?
Olive Green
Fatty Acid and Alcohol
Initiation - Propagation - Termination
Acetoin

30. What two enzymes degrade pectic substances?
Pectin methylesterase & polygalacturonase
Osmosis
Initiation - Propagation - Termination
Daminozide

31. At low water activity What is the main deteriorative concern?
A concentrate of microfibrillar proteins of fish muscle.
Emulsification
Lipid oxidation
Microorganisms are very versatile - MO's can be altered by mutations or genetic engineering to produce a greater quantity of enzyme or different enzymes - recovery of enzymes is often easy - readily available - high rate of growth and enzyme producti

32. What is the fundamental driving of electrophoresis?
Chitin
The speed of a molecule is proportional to the surrounding voltage gradient.
Microorganisms are very versatile - MO's can be altered by mutations or genetic engineering to produce a greater quantity of enzyme or different enzymes - recovery of enzymes is often easy - readily available - high rate of growth and enzyme producti
Oil in Water

33. What two types of compounds are joined with an ester bond to make a wax?
Fatty Acid and Alcohol
Acsulfame-K - Saccharin - Cyclamate - Aspartame
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Onions ( or leeks)

34. Name three non-nutritive sweeteners approved for use in USA?
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Acsulfame-K - Saccharin - Cyclamate - Aspartame
2.5

35. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
Carrageenan
Erythorbic Acid
Bitter
Tryptophan

36. Name 3 physical agents capable of denaturing proteins.
Carrageenan
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Olive Green
Microorganisms are very versatile - MO's can be altered by mutations or genetic engineering to produce a greater quantity of enzyme or different enzymes - recovery of enzymes is often easy - readily available - high rate of growth and enzyme producti

37. If oxygen attacks an unsaturated fatty acids at the double bond What is the resultant product?
Arachidonic Acid
Two aldehydes
pH below positive charge; pH at no charge; pH above negative charge
Lamellar; Hexagonal I - II; Cubic

38. What is the enzyme responsible for browning in apples and lettuce?
No
Polyphenol Oxidase
Blue pigment in flowers
HPLC has higher pressure than FPLC

39. What are colloids that are stabilized by a layer of solvation called?
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Emulsoids

40. What is acid proteolysis?
Degradation of protein and production of acid from sugar at the same time.
Lipase
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.
Two aldehydes

41. The undesirable clarification of orange juice or tomato juice (precipitation of pulp) is caused by what enzymes?
Pheophytia does not have magnesium in porphyrin ring.
Pectin methyl esterase or galacturonase
Lipid oxidation
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents

42. What are the three stages of oxidative rancidity?
Initiation - Propagation - and Termination
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Pectin Esterase - Polygalacturonase - Pectin Layase
Yes

43. What is the fundamental driving of electrophoresis?
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Thamautin
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
The speed of a molecule is proportional to the surrounding voltage gradient.

44. An emulsifier with a high hydrophilic-lipophilic balance (HLB) value would promote which type of emulsion: oil in water or water in oil?
Oil in Water
Pectins
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
The speed of a molecule is proportional to the surrounding voltage gradient.

45. The undesirable clarification of orange juice or tomato juice (precipitation of pulp) is caused by what enzymes?
Water
Polyphenol Oxidase
Pectin methyl esterase or galacturonase
DNA transferred by cell to cell contact (bacterial sex).

46. What enzyme causes hyrolytic rancidity in milk?
Milk
Lipid oxidation
Lipase
Nucleation or crystal formation and crystal growth.

47. Name three nonpolar polar - and charged amino acids.
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Acetoin
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Chlocophyllide does not have a phytoltail

48. What is Carboxy-methyl cellulose often used for?
Sucrose
Thickener in foods
Pectin methyl esterase or galacturonase
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).

49. At what pH is benzoic acid most effective?
pH 3-5
Tryptophan
Tryptophan
NaCl (it dissociated to a 2M solution)

50. How many polypeptide chains make up an antibody?
Nucleation or crystal formation and crystal growth.
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
2.5
Four