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. Name 3 physical agents capable of denaturing proteins.
Chlocophyllide does not have a phytoltail
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents

2. What two enzymes degrade pectic substances?
Pectins
They act as catalysts - speeding the polymerization of acrylamide.
Pectin methylesterase & polygalacturonase
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.

3. What is catalase?
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
Pectin methylesterase & polygalacturonase
Chlocophyllide does not have a phytoltail
An enzyme that converts hydrogen peroxide to water plus oxygen.

4. How is pH defined?
Negative log of the hydrogen concentration (mol/l).
RNA transcribed to DNA
Carrageenan
HPLC has higher pressure than FPLC

5. When heated ammonium bicarbonate decomposes to form what end products?
Ammonia - Water - Carbon Dioxide
Arachidonic Acid
Daminozide
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

6. Food additive that could be used to prevent cocoa particles from settling in chocolate milk
Carrageenan
DNA transferred by cell to cell contact (bacterial sex).
Speed of Light
It explodes

7. Name three nonpolar polar - and charged amino acids.
Speed of Light
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
RNA transcribed to DNA
Anthocyanins

8. What are the three stages of oxidative rancidity?
Ascorbic Acid and Citric Acid
Thickener in foods
Troponins and Tropomyosin
Initiation - Propagation - and Termination

9. Name a commonly used household chemical leavening agent and the gas it generates.
Glycosides of anthocyanidins
Pectins
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Sodium bicarbonate generates CO2

10. What are the only phenols approved for use in the microbiological preservation of foods?
Racemic Mixture
Emulsoids
Non-protein nitrogen
Parabens

11. What two types of compounds are joined with an ester bond to make a wax?
Carmelization and Maillard
Erythorbic Acid
Milk
Fatty Acid and Alcohol

12. What is the protein efficiency ratio (PER) of casein?
Bright green
Fatty Acid and Alcohol
RNA transcribed to DNA
2.5

13. Name two non-enzymatic browning reactions.
Four
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Carmelization and Maillard
Daminozide

14. 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
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Sodium chloride reduces foam stability and sucrose improves foam stability.

15. How many polypeptide chains make up an antibody?
ERH=100 x Aw
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.
Phenylketonuria
Four

16. Does kosmotrophil ion discourage water structure?
No
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Lipase
Pectin Esterase - Polygalacturonase - Pectin Layase

17. What charge will a protein have when the pH of its solution is below at - and above its pKa?
Pheophytia does not have magnesium in porphyrin ring.
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
pH below positive charge; pH at no charge; pH above negative charge
20 carbons and 4 double bonds

18. What is the chemical nature of anthocyanins?
Glycosides of anthocyanidins
Linoleic Acid
It explodes
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.

19. Name a naturally occurring protein sweetener.
Thamautin
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.

20. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
Bitter
Pectins
Lycopenes
Acsulfame-K - Saccharin - Cyclamate - Aspartame

21. What does the 'c' stand for in the equation E=mc2?
Ascorbic Acid and Citric Acid
Speed of Light
Thickener in foods
Racemic Mixture

22. 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
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Emulsoids
Four
D: None of the above

23. Name the strongest biochemical bond and the weakest biochemical bond.
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Covalent (strongest) and Hydrophobic (Weakest)
Carrageenan
Browning of freshly cut surfaces of fruits and vegetables.

24. Give one word for a carbon atom involved in hemiacetal or acetal formation.
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
2.5
Pectin methyl esterase or galacturonase
Anomeric

25. What pigment was first designated as anthocyanins?
2.5
Thermus Aqauticus
Oil in Water
Blue pigment in flowers

26. What are the primary secondary - tertiary - and quaternary structures?
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Pectins
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.

27. What is the main class of color compounds found in raspberries?
Yellow
Initiation - Propagation - Termination
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Anthocyanins

28. In what food is butyric acid typically found?
Milk
Plasmids
Pectin methylesterase & polygalacturonase
Degradation of protein and production of acid from sugar at the same time.

29. Name 3 factors influencing the consistency of commercial fats.
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Whole Milk
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Number of fatty acids present; mg KOH needed to saponify 1 g fat.

30. What does Reichert-Meissert Number measure?
Primary butyric acid also caproic acid.
45% - 52% - 90%
Emulsoids
Degradation of protein and production of acid from sugar at the same time.

31. Which amino acid has the greatest molecular weight: tryptophan or tyrosine?
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Lysine - Arginine - and Histidine
Tryptophan
Osmosis

32. What two common compounds are used together as an antioxidative system?
Browning of freshly cut surfaces of fruits and vegetables.
Ascorbic Acid and Citric Acid
Tryptophan
2.5

33. Name 3 chemical agents capable of denaturing proteins.
Carmelization and Maillard
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Number of fatty acids present; mg KOH needed to saponify 1 g fat.

34. A) Is the major component of most foods.B) Controls shelf-life or storage capabilityC) Regulates chemical and microbiological reactionsD) All of the above
Sucrose
Water
Anomeric
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

35. Name three compounds capable of poisoning the catalyst during commercial hydrogenation.
Bitter
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Emulsoids
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.

36. What does MSG stand for?
Sodium bicarbonate generates CO2
Monosodium Glutamate
Pectin Esterase
Covalent (strongest) and Hydrophobic (Weakest)

37. Is a disaccharide
Sucrose
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
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Initiation - Propagation - Termination

38. What two types of compounds are joined with an ester bond to make a wax?
Lysine - Arginine - and Histidine
Fatty Acid and Alcohol
Daminozide
Pectin Esterase - Polygalacturonase - Pectin Layase

39. What is the chemical nomenclature for caffeine?
Chlocophyllide does not have a phytoltail
Four
1 - 3 - 7-trimethylxanthine
Anomeric

40. What does the 'c' stand for in the equation E=mc2?
Phenylketonuria
Thickener in foods
Speed of Light
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.

41. Name the two components that comprise the relaxing factor in muscle fibers.
Troponins and Tropomyosin
45% - 52% - 90%
Pectin methyl esterase or galacturonase
Pheophytin forms

42. What is the structural difference between chlorophyll and pheophytia?
Chlocophyllide does not have a phytoltail
Pheophytia does not have magnesium in porphyrin ring.
Negative log of the hydrogen concentration (mol/l).
Aspartic Acid and Phenylalanine

43. What is the enzyme responsible for browning in apples and lettuce?
Polyphenol Oxidase
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Tryptophan
Arachidonic Acid

44. How do sodium chloride and sucrose affect foam stability?
V=IR and P=VI or I x I x are
Carrageenan
Sodium chloride reduces foam stability and sucrose improves foam stability.
Number of fatty acids present; mg KOH needed to saponify 1 g fat.

45. The undesirable clarification of orange juice or tomato juice (precipitation of pulp) is caused by what enzymes?
NaCl (it dissociated to a 2M solution)
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Pectin methyl esterase or galacturonase
Primary butyric acid also caproic acid.

46. What does the acronym NPN stand for?
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Chlocophyllide does not have a phytoltail
Non-protein nitrogen

47. What are the four basic flavors perceived by the tongue?
Gliadins and Glutenins
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.
Sweet - Salty - Sour - and Bitter
Emulsification

48. How does HPLC differ from FPLC?
HPLC has higher pressure than FPLC
No
Carmelization and Maillard
RNA transcribed to DNA

49. What is the winterization process for an oil?
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Parabens
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Initiation - Propagation - Termination

50. What ketohexose is most significant to food chemists?
Fructose
Covalent (strongest) and Hydrophobic (Weakest)
Four
Acetoin