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 5 proteins with good foaming properties.
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.
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.
Bitter
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.

2. Name the most common functional property of phospholipids in food systems.
Erythorbic Acid
Emulsification
2.5
Tryptophan

3. Name a commonly used household chemical leavening agent and the gas it generates.
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
DNA transferred by cell to cell contact (bacterial sex).
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Sodium bicarbonate generates CO2

4. What is acid proteolysis?
ERH=100 x Aw
Degradation of protein and production of acid from sugar at the same time.
Non-protein nitrogen
Polyphenol Oxidase

5. Name 3 physical agents capable of denaturing proteins.
Water
Pectin methylesterase & polygalacturonase
Pectin Esterase
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces

6. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
Pectin methylesterase & polygalacturonase
45% - 52% - 90%
Lysine - Arginine - and Histidine
Butter= water in oil Mayonnaise= oil in water Milk= oil in water

7. Name three factors useful in controlling enzyme activity.
Orange Juice
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Lipid oxidation
Non-protein nitrogen

8. What is the common name for 9 12 - cis-cis-octa dienoic acid?
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Capsaicin
Linoleic Acid
Lamellar; Hexagonal I - II; Cubic

9. A chlorophyll molecule reacting with hydrogen exhibits what shade of green?
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Initiation - Propagation - and Termination
Olive Green
Tryptophan

10. What does the iodine value measure and how is it measured?
Parabens
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Polyphenol Oxidase
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.

11. If you take 20 ml of .1 M NaOH to titrate 40 mL of an HCL solution to the penolphthalein end point What is the molarity of the HCL solution?
.05 M HCL
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Lysine - Arginine - and Histidine
Pectin methyl esterase or galacturonase

12. What are the three main steps in the autooxidation of lipids?
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Initiation - Propagation - Termination
Fatty Acid (Ester linked) to Fatty Alcohol

13. In the enzyme Taq Polymerase What does Taq stand for?
Four
Pectin Esterase
Whole Milk
Thermus Aqauticus

14. What are the four basic flavors perceived by the tongue?
Sweet - Salty - Sour - and Bitter
Fructose
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.
Daminozide

15. What are 3 mesomorphic structures associated with lipids in the liquid state?
They act as catalysts - speeding the polymerization of acrylamide.
Lamellar; Hexagonal I - II; Cubic
Olive Green
Anomeric

16. Alar is the trade name for what chemical compound?
DNA transferred by cell to cell contact (bacterial sex).
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Daminozide
Gliadins and Glutenins

17. What are the three main steps in the autooxidation of lipids?
Initiation - Propagation - Termination
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Negative log of the hydrogen concentration (mol/l).

18. What enzyme causes hyrolytic rancidity in milk?
Lipase
Sweet - Salty - Sour - and Bitter
No
Number of fatty acids present; mg KOH needed to saponify 1 g fat.

19. Name 3 chemical agents capable of denaturing proteins.
The speed of a molecule is proportional to the surrounding voltage gradient.
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
2.5
Erythorbic Acid

20. If the absorption of a sample is being determined spectrophotometrically at 420 nm what color is the sample?
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Lycopenes
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Yellow

21. What is an isomer that is cheaper than Vitamin C?
Covalent (strongest) and Hydrophobic (Weakest)
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Milk
Erythorbic Acid

22. A chlorophyll molecule reacting with magnesium exhibits what shade of green?
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Bright green
Blue pigment in flowers
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)

23. Does kosmotrophil ion discourage water structure?
14
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Anomeric
No

24. Alar is the trade name for what chemical compound?
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Tryptophan
Racemic Mixture
Daminozide

25. What is surimi?
Gliadins and Glutenins
Carrageenan
A concentrate of microfibrillar proteins of fish muscle.
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.

26. Define molarity molality - and normality.
Thickener in foods
Fatty Acid (Ester linked) to Fatty Alcohol
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 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.

27. What is the enzyme responsible for browning in apples and lettuce?
Polyphenol Oxidase
V=IR and P=VI or I x I x are
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
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.

28. 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
Browning of freshly cut surfaces of fruits and vegetables.
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Thermus Aqauticus
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.

29. What are the primary secondary - tertiary - and quaternary structures?
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
D: None of the above
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.
1 - 3 - 7-trimethylxanthine

30. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
They act as catalysts - speeding the polymerization of acrylamide.
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
Parabens
Lipid oxidation

31. What is the structural difference between chlorophyll and chlocophyllide?
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Chlocophyllide does not have a phytoltail
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).

32. How do sodium chloride and sucrose affect foam stability?
Sodium chloride reduces foam stability and sucrose improves foam stability.
Parabens
Carmelization and Maillard
Butter= water in oil Mayonnaise= oil in water Milk= oil in water

33. Name two reasons why fats are hydrogenated.
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Polyphenol Oxidase
45% - 52% - 90%
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.

34. At low water activity What is the main deteriorative concern?
Yes
Lipid oxidation
Pectin methylesterase & polygalacturonase
Pectin Esterase - Polygalacturonase - Pectin Layase

35. Which amino acid has the greatest molecular weight: tryptophan or tyrosine?
Initiation - Propagation - and Termination
Chlocophyllide does not have a phytoltail
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.
Tryptophan

36. What metabolic disorder prevents conversion of phenulalanine to tyrosine by normal metabolic pathways?
Initiation - Propagation - Termination
Two aldehydes
Phenylketonuria
2.5

37. A) Is the major component of most foods.B) Controls shelf-life or storage capabilityC) Regulates chemical and microbiological reactionsD) All of the above
Pectin Esterase - Polygalacturonase - Pectin Layase
Water
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
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.

38. What does Acid Degree Value measure and how is it measured?
14
Arachidonic Acid
45% - 52% - 90%
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.

39. What two common compounds are used together as an antioxidative system?
Ascorbic Acid and Citric Acid
Water
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
Chlocophyllide does not have a phytoltail

40. Name the two components that comprise the relaxing factor in muscle fibers.
Troponins and Tropomyosin
Prolamines
No
Pectins

41. During freezing What are the two stages in the crystallization process?
Bitter
Fructose
Pectin methyl esterase or galacturonase
Nucleation or crystal formation and crystal growth.

42. How does HPLC differ from FPLC?
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.
Anthocyanins
pH below positive charge; pH at no charge; pH above negative charge
HPLC has higher pressure than FPLC

43. What metabolic end product does the Voges-Proskauer test detect?
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Pectins
Acetoin
Carmelization and Maillard

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
A concentrate of microfibrillar proteins of fish muscle.
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
HPLC has higher pressure than FPLC

45. What two common compounds are used together as an antioxidative system?
Cis
Initiation - Propagation - and Termination
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Ascorbic Acid and Citric Acid

46. A) Is the major component of most foods.B) Controls shelf-life or storage capabilityC) Regulates chemical and microbiological reactionsD) All of the above
Lipid oxidation
Water
Linoleic Acid
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.

47. Peptide bond formation results in the formation of what secondary compound?
Pectin methyl esterase or galacturonase
Water
Whole Milk
Polyphenoloxidase

48. What does the 'c' stand for in the equation E=mc2?
Pectin methyl esterase or galacturonase
Olive Green
Speed of Light
Emulsification

49. What does HLB stand for and What does a high and low HLB value indicate?
Prolamines
14
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
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 is the enzyme responsible for browning in apples and lettuce?
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Polyphenol Oxidase
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.
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).