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. In genetics What is conjugation?
DNA transferred by cell to cell contact (bacterial sex).
1 - 3 - 7-trimethylxanthine
Prolamines
Pheophytia does not have magnesium in porphyrin ring.

2. What does HLB stand for and What does a high and low HLB value indicate?
Daminozide
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.
20 carbons and 4 double bonds
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls

3. What is Ohm's Law and What is Power Equation?
14
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.
Fatty Acid (Ester linked) to Fatty Alcohol
V=IR and P=VI or I x I x are

4. Name the three positively charged amino acids.
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
HPLC has higher pressure than FPLC
Lysine - Arginine - and Histidine

5. How do sodium chloride and sucrose affect foam stability?
Lamellar; Hexagonal I - II; Cubic
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Sodium chloride reduces foam stability and sucrose improves foam stability.
Lipid oxidation

6. If the absorption of a sample is being determined spectrophotometrically at 420 nm what color is the sample?
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
Pectins
Yellow
Pectin Esterase - Polygalacturonase - Pectin Layase

7. What name is given to the small circular DNA molecules that carry genetic information independently of the main bacterial chromosome?
Arachidonic Acid
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Plasmids
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

8. 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?
It explodes
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
D: None of the above
No

9. Peptide bond formation results in the formation of what secondary compound?
Water
ERH=100 x Aw
Polyphenol Oxidase
14

10. What is the common name for 9 12 - cis-cis-octa dienoic acid?
Parabens
Acetoin
Linoleic Acid
Pectin methyl esterase or galacturonase

11. At what pH is benzoic acid most effective?
They act as catalysts - speeding the polymerization of acrylamide.
pH 3-5
Pectin methyl esterase or galacturonase
45% - 52% - 90%

12. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
Negative log of the hydrogen concentration (mol/l).
The speed of a molecule is proportional to the surrounding voltage gradient.
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

13. Does kosmotrophil ion discourage water structure?
Pheophytin forms
Racemic Mixture
Bitter
No

14. 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
Initiation - Propagation - Termination
2.5
Anthocyanins
D: None of the above

15. Name the two components that comprise the relaxing factor in muscle fibers.
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Yellow
Troponins and Tropomyosin
Prolamines

16. Which of the following examples of browning is enzymatic in nature? 1. Browning of sugars as a result of heating 2. Browning of freshly cut surfaces of fruits and vegetables 3. Browning of bread during toasting 4. Browning of potato chips
Water
Pheophytin forms
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
Browning of freshly cut surfaces of fruits and vegetables.

17. What are colloids that are stabilized by a layer of solvation called?
Four
Emulsoids
Pheophytin forms
Two aldehydes

18. What is a polymorphism?
Carrageenan
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Negative log of the hydrogen concentration (mol/l).
Chlocophyllide does not have a phytoltail

19. What are the three main steps in the autooxidation of lipids?
Daminozide
Ascorbic Acid and Citric Acid
DNA transferred by cell to cell contact (bacterial sex).
Initiation - Propagation - Termination

20. What pigment was first designated as anthocyanins?
Blue pigment in flowers
Olive Green
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

21. What is the name given to a mixture of equal parts of Darel Lisomers?
Water
Racemic Mixture
Osmosis
HPLC has higher pressure than FPLC

22. 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.
Pectins
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)

23. Name a naturally occurring protein sweetener.
Troponins and Tropomyosin
Thamautin
Milk
Bitter

24. Will lipid oxidation be higher at a water activity of .05 or .5?
Pectin methyl esterase or galacturonase
Fatty Acid and Alcohol
Plasmids
.05

25. Food additive that could be used to prevent cocoa particles from settling in chocolate milk
2.5
Carrageenan
Lamellar; Hexagonal I - II; Cubic
Orange Juice

26. Which of these foods is not appropriate to this list? A) Salami B) Yogurt C) Orange Juice D) Beer
Initiation - Propagation - and Termination
Chitin
Orange Juice
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.

27. What is the main class of color compounds found in raspberries?
Anthocyanins
Lipid oxidation
Pectin Esterase - Polygalacturonase - Pectin Layase
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

28. A) Is the major component of most foods.B) Controls shelf-life or storage capabilityC) Regulates chemical and microbiological reactionsD) All of the above
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Water
Monosodium Glutamate
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)

29. In genetics What is conjugation?
Tryptophan
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
DNA transferred by cell to cell contact (bacterial sex).
Four

30. What toxic pigment is found in cottonseed endosperm?
Speed of Light
Gossypol (it is removed during the oil refining process)
Polyphenols
Yes

31. 20 grams of amylose is added to 80 grams of water in a bearker; the boiling point is measured with an ordinary mercury-in-glass thermometer. What is the observed boiling point of the material in the beaker?
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Anomeric
Cis
Acsulfame-K - Saccharin - Cyclamate - Aspartame

32. What is Ohm's Law and What is Power Equation?
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
V=IR and P=VI or I x I x are
Two aldehydes
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.

33. Name 2 heat stable enzymes in food that are important to the quality of aseptic products.
Pectin Esterase
pH 3-5
Olive Green
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.

34. What does the 'c' stand for in the equation E=mc2?
Troponins and Tropomyosin
Pheophytin forms
Glycosides of anthocyanidins
Speed of Light

35. How is pH defined?
Emulsoids
Phenophylin
Negative log of the hydrogen concentration (mol/l).
Pheophytia does not have magnesium in porphyrin ring.

36. Alar is the trade name for what chemical compound?
Ascorbic Acid and Citric Acid
Daminozide
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Speed of Light

37. What chemical compound is responsible for the 'hot' principle of jalepeno peppers?
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
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
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Capsaicin

38. What is the enzyme that softens tomatoes?
Polyphenols
No
Four
Pectin Esterase

39. What is surimi?
A concentrate of microfibrillar proteins of fish muscle.
Linoleic Acid
Acetoin
Acetoin

40. How many carbon atoms and how many double bonds are there in arachidonic acid?
Fructose
20 carbons and 4 double bonds
Fatty Acid and Alcohol
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.

41. Which of these foods is not appropriate to this list? A) Salami B) Yogurt C) Orange Juice D) Beer
Pheophytin forms
Orange Juice
Acetoin
Initiation - Propagation - and Termination

42. What is a polymorphism?
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Polyphenoloxidase
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Emulsification

43. What is the structural difference between chlorophyll and chlocophyllide?
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Lamellar; Hexagonal I - II; Cubic
Chlocophyllide does not have a phytoltail

44. How does ERH relate to water activity?
ERH=100 x Aw
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
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Pectin Esterase - Polygalacturonase - Pectin Layase

45. Name three compounds capable of poisoning the catalyst during commercial hydrogenation.
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Chitin
Pectin Esterase - Polygalacturonase - Pectin Layase

46. What metabolic disorder prevents conversion of phenulalanine to tyrosine by normal metabolic pathways?
Phenylketonuria
Carrageenan
Negative log of the hydrogen concentration (mol/l).
Pectins

47. What effect would the addition of sodium bicarbonate have to chocolate?
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Pheophytin forms
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Ascorbic Acid and Citric Acid

48. Name 5 chelating agents used in the food industry.
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Chitin
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
NaCl (it dissociated to a 2M solution)

49. What does MSG stand for?
pH 3-5
Glycosides of anthocyanidins
Monosodium Glutamate
Glycosides of anthocyanidins

50. A chlorophyll molecule reacting with hydrogen exhibits what shade of green?
Milk
Olive Green
V=IR and P=VI or I x I x are
Fatty Acid (Ester linked) to Fatty Alcohol