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 the acronym NPN stand for?
Polyphenoloxidase
Thickener in foods
Onions ( or leeks)
Non-protein nitrogen

2. Contains the lowest content of water
ERH=100 x Aw
Osmosis
1 - 3 - 7-trimethylxanthine
Whole Milk

3. Match the number of carbon atoms with the common name of these saturated fatty acids. Carbon #: 4:0 10:0 - 12:0 -14:0 - 16:0 - 18:0Common Name: Myristic - Butyric - Capric - Lauric - Stearic - Palmitic
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Lycopenes
Anomeric
Yes

4. Name the two components that comprise the relaxing factor in muscle fibers.
Pheophytin forms
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Anthocyanins
Troponins and Tropomyosin

5. How is pH defined?
Negative log of the hydrogen concentration (mol/l).
Acsulfame-K - Saccharin - Cyclamate - Aspartame
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Racemic Mixture

6. Name 3 physical agents capable of denaturing proteins.
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Lysine - Arginine - and Histidine
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)

7. Are sorbitol and mannitol sweet?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Gliadins and Glutenins
Yes
Thermus Aqauticus

8. What does Reichert-Meissert Number measure?
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Yellow
pH 3-5
Primary butyric acid also caproic acid.

9. 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
Gossypol (it is removed during the oil refining process)
Two aldehydes
.05

10. What does the 'c' stand for in the equation E=mc2?
Negative log of the hydrogen concentration (mol/l).
Carrageenan
Speed of Light
Prolamines

11. Name two non-enzymatic browning reactions.
Thamautin
Daminozide
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Carmelization and Maillard

12. In the enzyme Taq Polymerase What does Taq stand for?
Thermus Aqauticus
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
It explodes
Fatty Acid and Alcohol

13. The undesirable clarification of orange juice or tomato juice (precipitation of pulp) is caused by what enzymes?
Aspartic Acid and Phenylalanine
Pectin methyl esterase or galacturonase
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Pheophytia does not have magnesium in porphyrin ring.

14. What name is given to the small circular DNA molecules that carry genetic information independently of the main bacterial chromosome?
Plasmids
Pectin methylesterase & polygalacturonase
Water
Polyphenols

15. Name one way foam stability can be assessed.
Lycopenes
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.
Monosodium Glutamate
Yellow

16. During freezing What are the two stages in the crystallization process?
It explodes
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.
Nucleation or crystal formation and crystal growth.
Negative log of the hydrogen concentration (mol/l).

17. What are soluble polymers of anhydro-galacturonic acid and its esters called?
Pectins
Negative log of the hydrogen concentration (mol/l).
Water
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.

18. What does the saponification value measure and how is it measured?
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)

19. How many carbon atoms are there in the fatty acid myristic acid?
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
14
Ascorbic Acid and Citric Acid
Daminozide

20. A chlorophyll molecule reacting with hydrogen exhibits what shade of green?
Onions ( or leeks)
Browning of freshly cut surfaces of fruits and vegetables.
D: None of the above
Olive Green

21. 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?
Osmosis
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

22. How many carbon atoms and how many double bonds are there in arachidonic acid?
Sucrose
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
20 carbons and 4 double bonds

23. In genetics What is conjugation?
Lycopenes
Polyphenol Oxidase
Sodium chloride reduces foam stability and sucrose improves foam stability.
DNA transferred by cell to cell contact (bacterial sex).

24. What is an isomer that is cheaper than Vitamin C?
Oil in Water
Erythorbic Acid
Thickener in foods
Carmelization and Maillard

25. What does MSG stand for?
Acetoin
Monosodium Glutamate
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
Lipid oxidation

26. Name two main gluten proteins.
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.
Gliadins and Glutenins
Plasmids
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.

27. What charge will a protein have when the pH of its solution is below at - and above its pKa?
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
pH below positive charge; pH at no charge; pH above negative charge
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
Carmelization and Maillard

28. Which will be coldest at its freezing point: 1M dispersion of amylose 1M solution of NaCl - distilled water - or 1M solution of sucrose?
Ammonia - Water - Carbon Dioxide
.05
NaCl (it dissociated to a 2M solution)
Gossypol (it is removed during the oil refining process)

29. Alar is the trade name for what chemical compound?
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
They act as catalysts - speeding the polymerization of acrylamide.
Olive Green
Daminozide

30. A) Is the major component of most foods.B) Controls shelf-life or storage capabilityC) Regulates chemical and microbiological reactionsD) All of the above
Phenylketonuria
The speed of a molecule is proportional to the surrounding voltage gradient.
DNA transferred by cell to cell contact (bacterial sex).
Water

31. What is the name of the degradation compound of chlorophyll?
Lycopenes
Arachidonic Acid
Four
Phenophylin

32. At low water activity What is the main deteriorative concern?
D: None of the above
Lipid oxidation
2.5
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.

33. What is an isomer that is cheaper than Vitamin C?
Erythorbic Acid
14
Polyphenol Oxidase
Non-protein nitrogen

34. What are the three main steps in the autooxidation of lipids?
RNA transcribed to DNA
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Ammonia - Water - Carbon Dioxide
Initiation - Propagation - Termination

35. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Fatty Acid (Ester linked) to Fatty Alcohol
45% - 52% - 90%
Oil in Water

36. The undesirable clarification of orange juice or tomato juice (precipitation of pulp) is caused by what enzymes?
Pectin methyl esterase or galacturonase
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Lipid oxidation
Pectin Esterase

37. What degradative enzyme causes browning in apples - pears - bananas - and peaches?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
D: None of the above
Polyphenoloxidase

38. Which of these foods is not appropriate to this list? A) Salami B) Yogurt C) Orange Juice D) Beer
Orange Juice
Troponins and Tropomyosin
2.5
Thermus Aqauticus

39. What are the three stages of oxidative rancidity?
Fatty Acid and Alcohol
Initiation - Propagation - and Termination
Troponins and Tropomyosin
Pheophytin forms

40. What is the name of the degradation compound of chlorophyll?
Cis
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Phenophylin

41. 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.
Sweet - Salty - Sour - and Bitter
Onions ( or leeks)
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.

42. What is the enzyme responsible for browning in apples and lettuce?
NaCl (it dissociated to a 2M solution)
Polyphenol Oxidase
Gossypol (it is removed during the oil refining process)
2.5

43. What does HLB stand for and What does a high and low HLB value indicate?
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.
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.
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
Pheophytia does not have magnesium in porphyrin ring.

44. What is acid proteolysis?
Chitin
Degradation of protein and production of acid from sugar at the same time.
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Tryptophan

45. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
Sucrose
Onions ( or leeks)
2.5
Lamellar; Hexagonal I - II; Cubic

46. Alar is the trade name for what chemical compound?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Daminozide
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.

47. What is the fundamental driving of electrophoresis?
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Anomeric
Non-protein nitrogen
The speed of a molecule is proportional to the surrounding voltage gradient.

48. What are two common reducing agents that break disulfide bonds in proteins?
Emulsoids
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Linoleic Acid
V=IR and P=VI or I x I x are

49. What chemical compound is responsible for the 'hot' principle of jalepeno peppers?
DNA transferred by cell to cell contact (bacterial sex).
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
45% - 52% - 90%
Capsaicin

50. What enzyme is most responsible for browning bananas?
Polyphenol Oxidase
Lamellar; Hexagonal I - II; Cubic
Initiation - Propagation - Termination
Speed of Light