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 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.
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Non-protein nitrogen
Water

2. Contains the lowest content of water
Whole Milk
Sweet - Salty - Sour - and 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).
Pectin Esterase

3. What two enzymes degrade pectic substances?
Osmosis
Initiation - Propagation - Termination
Pectin methyl esterase or galacturonase
Pectin methylesterase & polygalacturonase

4. Name a naturally occurring protein sweetener.
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Lipid oxidation
Thamautin

5. What is catalase?
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
An enzyme that converts hydrogen peroxide to water plus oxygen.
Polyphenoloxidase
Polyphenol Oxidase

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

Warning: Invalid argument supplied for foreach() in /var/www/html/basicversity.com/show_quiz.php on line 183

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

Warning: Invalid argument supplied for foreach() in /var/www/html/basicversity.com/show_quiz.php on line 183

8. Does kosmotrophil ion discourage water structure?
Sweet - Salty - Sour - and Bitter
Yellow
No
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants

9. 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
Sucrose
D: None of the above
It explodes
Phenophylin

10. What is the enzyme responsible for browning in apples and lettuce?
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Arachidonic Acid
Negative log of the hydrogen concentration (mol/l).
Polyphenol Oxidase

11. What charge will a protein have when the pH of its solution is below at - and above its pKa?
pH below positive charge; pH at no charge; pH above negative charge
Parabens
Prolamines
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls

12. What degradative enzyme causes browning in apples - pears - bananas - and peaches?
Carrageenan
Cis
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Polyphenoloxidase

13. What metabolic disorder prevents conversion of phenulalanine to tyrosine by normal metabolic pathways?
Negative log of the hydrogen concentration (mol/l).
Phenylketonuria
Chitin
Onions ( or leeks)

14. Name three factors useful in controlling enzyme activity.
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Anomeric
ERH=100 x Aw

15. What are the three stages of oxidative rancidity?
Sodium bicarbonate generates CO2
Yes
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Initiation - Propagation - and Termination

16. What is the protein efficiency ratio (PER) of casein?
2.5
Sodium bicarbonate generates CO2
pH below positive charge; pH at no charge; pH above negative charge
Osmosis

17. How is pH defined?
Thermus Aqauticus
Polyphenol Oxidase
Negative log of the hydrogen concentration (mol/l).
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.

18. Waxes are composed of what two basic chemical entities?
Fatty Acid (Ester linked) to Fatty Alcohol
Polyphenols
1 - 3 - 7-trimethylxanthine
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.

19. What is the fundamental driving of electrophoresis?
HPLC has higher pressure than FPLC
The speed of a molecule is proportional to the surrounding voltage gradient.
.05 M HCL
Sodium bicarbonate generates CO2

20. What is the chemical nomenclature for caffeine?
A concentrate of microfibrillar proteins of fish muscle.
The speed of a molecule is proportional to the surrounding voltage gradient.
Fructose
1 - 3 - 7-trimethylxanthine

21. How many carbon atoms and how many double bonds are there in arachidonic acid?
Fat Oxidation
20 carbons and 4 double bonds
The speed of a molecule is proportional to the surrounding voltage gradient.
2.5

22. What are two common reducing agents that break disulfide bonds in proteins?
Emulsoids
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
HPLC has higher pressure than FPLC
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)

23. What pigment was first designated as anthocyanins?
Primary butyric acid also caproic acid.
Covalent (strongest) and Hydrophobic (Weakest)
Negative log of the hydrogen concentration (mol/l).
Blue pigment in flowers

24. Name 3 factors influencing the rate of lipid oxidation in foods.
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Lycopenes
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Pectin methylesterase & polygalacturonase

25. Name 2 heat stable enzymes in food that are important to the quality of aseptic products.
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
.05
Gliadins and Glutenins
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.

26. What pigment was first designated as anthocyanins?
Blue pigment in flowers
Orange Juice
The speed of a molecule is proportional to the surrounding voltage gradient.
Primary butyric acid also caproic acid.

27. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
They act as catalysts - speeding the polymerization of acrylamide.
Yellow
Sodium chloride reduces foam stability and sucrose improves foam stability.
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)

28. Name two reasons why fats are hydrogenated.
Monosodium Glutamate
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Phenophylin
Sodium bicarbonate generates CO2

29. Name three nonpolar polar - and charged amino acids.
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Arachidonic Acid
Pectin Esterase
pH 3-5

30. What are two common reducing agents that break disulfide bonds in proteins?
Pectins
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Primary butyric acid also caproic acid.
Linoleic Acid

31. What is the movement of molecules through a semi permeable membrane from a region of low to high solute concentration called?
DNA transferred by cell to cell contact (bacterial sex).
Osmosis
It explodes
pH below positive charge; pH at no charge; pH above negative charge

32. Name 5 chelating agents used in the food industry.
Troponins and Tropomyosin
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Sucrose
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)

33. What is the Peroxide Value a measure of?
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Fat Oxidation
Bright green
RNA transcribed to DNA

34. What are the limiting amino acids in corn - potato - and green peas?
Daminozide
Yes
Blue pigment in flowers
Corn- Lysine - Potato-Methionine - Green Peas-Methionine

35. When heated ammonium bicarbonate decomposes to form what end products?
Thickener in foods
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Pheophytia does not have magnesium in porphyrin ring.
Ammonia - Water - Carbon Dioxide

36. Which amino acid has the greatest molecular weight: tryptophan or tyrosine?
Tryptophan
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Sweet - Salty - Sour - and Bitter
Lipase

37. Name one way foam stability can be assessed.
Water
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Degradation of protein and production of acid from sugar at the same time.
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.

38. What is the main class of color compounds found in raspberries?
Fat Oxidation
45% - 52% - 90%
Capsaicin
Anthocyanins

39. Waxes are composed of what two basic chemical entities?
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Sodium bicarbonate generates CO2
Gliadins and Glutenins
Fatty Acid (Ester linked) to Fatty Alcohol

40. Will lipid oxidation be higher at a water activity of .05 or .5?
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Linoleic Acid
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
.05

41. If oxygen attacks an unsaturated fatty acids at the double bond What is the resultant product?
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Two aldehydes
Ascorbic Acid and Citric Acid
Oil in Water

42. What are colloids that are stabilized by a layer of solvation called?
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Emulsoids
Pectin methylesterase & polygalacturonase
Pectins

43. A chlorophyll molecule reacting with magnesium exhibits what shade of green?
Water
Bright green
Tryptophan
Fat Oxidation

44. What enzyme causes hyrolytic rancidity in milk?
Lipase
Phenylketonuria
Pheophytia does not have magnesium in porphyrin ring.
Thamautin

45. Does kosmotrophil ion discourage water structure?
Initiation - Propagation - and Termination
Lamellar; Hexagonal I - II; Cubic
No
Degradation of protein and production of acid from sugar at the same time.

46. How is pH defined?
V=IR and P=VI or I x I x are
It explodes
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Negative log of the hydrogen concentration (mol/l).

47. Name 3 factors influencing the consistency of commercial fats.
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Erythorbic Acid
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Troponins and Tropomyosin

48. What is the name given to a mixture of equal parts of Darel Lisomers?
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Lysine - Arginine - and Histidine
Racemic Mixture
D: None of the above

49. How does HPLC differ from FPLC?
Daminozide
HPLC has higher pressure than FPLC
They act as catalysts - speeding the polymerization of acrylamide.
Daminozide

50. Is a disaccharide
Chlocophyllide does not have a phytoltail
Chlocophyllide does not have a phytoltail
Sucrose
Water