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Food Chemistry

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Answer 50 questions in 15 minutes.
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Match each statement with the correct term.
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1. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
They act as catalysts - speeding the polymerization of acrylamide.
Polyphenoloxidase
Phenylketonuria
Pheophytin forms

2. What is the enzyme that softens tomatoes?
Water
Four
Pectin Esterase
Olive Green

3. What is the fundamental driving of electrophoresis?
Phenophylin
Ammonia - Water - Carbon Dioxide
Anthocyanins
The speed of a molecule is proportional to the surrounding voltage gradient.

4. How many polypeptide chains make up an antibody?
Four
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.

5. What is the name of the structural carbohydrate found in lobsters crab - shellfish - and insects?
Pheophytia does not have magnesium in porphyrin ring.
An enzyme that converts hydrogen peroxide to water plus oxygen.
Pectin Esterase - Polygalacturonase - Pectin Layase
Chitin

6. Name 5 proteins with good foaming properties.
Polyphenol Oxidase
Pectins
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.
.05

7. Name the three positively charged amino acids.
Lysine - Arginine - and Histidine
Parabens
Troponins and Tropomyosin
Fat Oxidation

8. Which will be coldest at its freezing point: 1M dispersion of amylose 1M solution of NaCl - distilled water - or 1M solution of sucrose?
Sodium bicarbonate generates CO2
Nucleation or crystal formation and crystal growth.
NaCl (it dissociated to a 2M solution)
Degradation of protein and production of acid from sugar at the same time.

9. Name two reasons why fats are hydrogenated.
Carmelization and Maillard
Lipid oxidation
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Anthocyanins

10. What is the movement of molecules through a semi permeable membrane from a region of low to high solute concentration called?
Pectin methyl esterase or galacturonase
D: None of the above
Acetoin
Osmosis

11. What name is given to the small circular DNA molecules that carry genetic information independently of the main bacterial chromosome?
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Plasmids
Two aldehydes
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).

12. Name 5 chelating agents used in the food industry.
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Lipase
Thamautin
Whole Milk

13. Name three nonpolar polar - and charged amino acids.
.05 M HCL
Two aldehydes
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Lipase

14. Name the two components that comprise the relaxing factor in muscle fibers.
Troponins and Tropomyosin
Ammonia - Water - Carbon Dioxide
Bitter
20 carbons and 4 double bonds

15. What is the main class of color compounds found in raspberries?
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Anthocyanins
.05
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

16. In genetics What is conjugation?
V=IR and P=VI or I x I x are
Cis
DNA transferred by cell to cell contact (bacterial sex).
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.

17. Name the three positively charged amino acids.
Lysine - Arginine - and Histidine
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Gossypol (it is removed during the oil refining process)
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.

18. What effect would the addition of sodium bicarbonate have to chocolate?
Pectin methylesterase & polygalacturonase
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
A concentrate of microfibrillar proteins of fish muscle.
Arachidonic Acid

19. Name two non-enzymatic browning reactions.
Sodium bicarbonate generates CO2
Carmelization and Maillard
Sucrose
20 carbons and 4 double bonds

20. What is surimi?
Daminozide
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
A concentrate of microfibrillar proteins of fish muscle.
Glycosides of anthocyanidins

21. What metabolic disorder prevents conversion of phenulalanine to tyrosine by normal metabolic pathways?
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.
Phenylketonuria
Fatty Acid (Ester linked) to Fatty Alcohol
Parabens

22. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
The degree of liquid drainage or foam collapse (foam reduction) after a given time - the time for total or half-drainage (or half-reduction in volume) - or the time before drainage starts.
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Two aldehydes
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.

23. What is an isomer that is cheaper than Vitamin C?
Erythorbic Acid
NaCl (it dissociated to a 2M solution)
They act as catalysts - speeding the polymerization of acrylamide.
Anthocyanins

24. What are soluble polymers of anhydro-galacturonic acid and its esters called?
Racemic Mixture
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Pectins
Phenylketonuria

25. Q What reaction does the enzyme 'reverse transcriptase' catalyze?
RNA transcribed to DNA
45% - 52% - 90%
Browning of freshly cut surfaces of fruits and vegetables.
Nucleation or crystal formation and crystal growth.

26. What is the name of the degradation compound of chlorophyll?
Thamautin
Chlocophyllide does not have a phytoltail
Phenophylin
Lysine - Arginine - and Histidine

27. What charge will a protein have when the pH of its solution is below at - and above its pKa?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
pH below positive charge; pH at no charge; pH above negative charge
Capsaicin
Negative log of the hydrogen concentration (mol/l).

28. What are colloids that are stabilized by a layer of solvation called?
Emulsoids
Whole Milk
pH 3-5
Lysine - Arginine - and Histidine

29. What is the chemical nature of anthocyanins?
Glycosides of anthocyanidins
Aspartic Acid and Phenylalanine
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Olive Green

30. Name 3 factors influencing the rate of lipid oxidation in foods.
pH 3-5
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Acetoin
Carmelization and Maillard

31. Contains the lowest content of water
Whole Milk
45% - 52% - 90%
Lipid oxidation
Carmelization and Maillard

32. Which two amino acids is the aspartame derived from?
Olive Green
No
2.5
Aspartic Acid and Phenylalanine

33. What enzyme is most responsible for browning bananas?
Polyphenol Oxidase
Linoleic Acid
Orange Juice
Whole Milk

34. What chemical compound is responsible for the 'hot' principle of jalepeno peppers?
Prolamines
Capsaicin
The speed of a molecule is proportional to the surrounding voltage gradient.
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.

35. What are the only phenols approved for use in the microbiological preservation of foods?
Daminozide
Non-protein nitrogen
Bitter
Parabens

36. What are the primary secondary - tertiary - and quaternary structures?
Initiation - Propagation - Termination
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
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.
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).

37. Name three effects of protein denaturation.
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Daminozide
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Daminozide

38. What is the enzyme responsible for browning in apples and lettuce?
Polyphenol Oxidase
Fatty Acid and Alcohol
D: None of the above
45% - 52% - 90%

39. What are 3 mesomorphic structures associated with lipids in the liquid state?
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Carmelization and Maillard
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Lamellar; Hexagonal I - II; Cubic

40. A chlorophyll molecule reacting with magnesium exhibits what shade of green?
Pectin Esterase - Polygalacturonase - Pectin Layase
Bright green
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Carmelization and Maillard

41. Name three effects of protein denaturation.
Phenophylin
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Pheophytin forms
Emulsification

42. Contains the lowest content of water
Lamellar; Hexagonal I - II; Cubic
Whole Milk
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Yellow

43. What is the name given to a mixture of equal parts of Darel Lisomers?
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Lysine - Arginine - and Histidine
Gliadins and Glutenins
Racemic Mixture

44. A chlorophyll molecule reacting with hydrogen exhibits what shade of green?
Non-protein nitrogen
Olive Green
.05 M HCL
Monosodium Glutamate

45. What is the geometric configuration of double bonds in most natural fatty acids?
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Erythorbic Acid
Phenophylin
Cis

46. What does the saponification value measure and how is it measured?
pH 3-5
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Erythorbic Acid
Lipase

47. What does Acid Degree 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.
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
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
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

48. What does Reichert-Meissert Number measure?
Primary butyric acid also caproic acid.
Lycopenes
Prolamines
Chitin

49. What would be a safe processing time for heat processing green beans in a boiling water bath? A. 30 minutes B. 300 minutes C. Depends on the size of the food container D. None of the above
Thermus Aqauticus
V=IR and P=VI or I x I x are
D: None of the above
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.

50. What metabolic end product does the Voges-Proskauer test detect?
Lysine - Arginine - and Histidine
Water
Troponins and Tropomyosin
Acetoin