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 three compounds capable of poisoning the catalyst during commercial hydrogenation.
.05 M HCL
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Phenophylin
Fatty Acid and Alcohol

2. What are 3 mesomorphic structures associated with lipids in the liquid state?
Troponins and Tropomyosin
Degradation of protein and production of acid from sugar at the same time.
Lamellar; Hexagonal I - II; Cubic
The speed of a molecule is proportional to the surrounding voltage gradient.

3. In the enzyme Taq Polymerase What does Taq stand for?
Thermus Aqauticus
2.5
Lamellar; Hexagonal I - II; Cubic
Lysine - Arginine - and Histidine

4. What is the structural difference between chlorophyll and pheophytia?
Sweet - Salty - Sour - and Bitter
Pheophytia does not have magnesium in porphyrin ring.
Bitter
Polyphenol Oxidase

5. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Osmosis
Non-protein nitrogen
Butter= water in oil Mayonnaise= oil in water Milk= oil in water

6. How many carbon atoms and how many double bonds are there in arachidonic acid?
Lysine - Arginine - and Histidine
20 carbons and 4 double bonds
Fructose
Glycosides of anthocyanidins

7. Name two non-enzymatic browning reactions.
Carmelization and Maillard
Initiation - Propagation - Termination
Carrageenan
Anomeric

8. Name a naturally occurring protein sweetener.
Carmelization and Maillard
Milk
Pectin Esterase - Polygalacturonase - Pectin Layase
Thamautin

9. 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
Polyphenol Oxidase
Browning of freshly cut surfaces of fruits and vegetables.
Aspartic Acid and Phenylalanine

10. At low water activity What is the main deteriorative concern?
Lipid oxidation
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
2.5
NaCl (it dissociated to a 2M solution)

11. Name 3 physical agents capable of denaturing proteins.
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
A concentrate of microfibrillar proteins of fish muscle.
Linoleic Acid
Whole Milk

12. What chemical compound is responsible for the 'hot' principle of jalepeno peppers?
Nucleation or crystal formation and crystal growth.
Acsulfame-K - Saccharin - Cyclamate - Aspartame
D: None of the above
Capsaicin

13. If oxygen attacks an unsaturated fatty acids at the double bond What is the resultant product?
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
DNA transferred by cell to cell contact (bacterial sex).
Two aldehydes
Non-protein nitrogen

14. Q What reaction does the enzyme 'reverse transcriptase' catalyze?
RNA transcribed to DNA
It explodes
Bitter
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.

15. What are the primary secondary - tertiary - and quaternary structures?
45% - 52% - 90%
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.
Non-protein nitrogen
Fructose

16. What does the acronym NPN stand for?
Non-protein nitrogen
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Sucrose

17. What is the structural difference between chlorophyll and pheophytia?
Pheophytia does not have magnesium in porphyrin ring.
Initiation - Propagation - and Termination
Sodium chloride reduces foam stability and sucrose improves foam stability.
Acetoin

18. What compounds oxidize to form brown color in fruits and vegetables?
Lycopenes
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.
Polyphenols
Speed of Light

19. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
Two aldehydes
Degradation of protein and production of acid from sugar at the same time.
Degradation of protein and production of acid from sugar at the same time.
Butter= water in oil Mayonnaise= oil in water Milk= oil in water

20. What is the chemical nomenclature for caffeine?
Bitter
1 - 3 - 7-trimethylxanthine
Water
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.

21. Name 3 physical agents capable of denaturing proteins.
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.
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
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
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

22. Name the most common functional property of phospholipids in food systems.
Chlocophyllide does not have a phytoltail
Fatty Acid (Ester linked) to Fatty Alcohol
Emulsification
Gliadins and Glutenins

23. 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.
V=IR and P=VI or I x I x are
Oil in Water
Tryptophan

24. A chlorophyll molecule reacting with magnesium exhibits what shade of green?
Fatty Acid and Alcohol
Pectin Esterase
Bright green
Polyphenol Oxidase

25. What enzyme causes hyrolytic rancidity in milk?
Plasmids
Lipase
They act as catalysts - speeding the polymerization of acrylamide.
Polyphenol Oxidase

26. If oxygen attacks an unsaturated fatty acids at the double bond What is the resultant product?
Prolamines
pH below positive charge; pH at no charge; pH above negative charge
Bitter
Two aldehydes

27. 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?
Polyphenol Oxidase
Olive Green
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
.05 M HCL

28. How many polypeptide chains make up an antibody?
Acetoin
Pectins
Milk
Four

29. 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
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Tryptophan
Pectin Esterase - Polygalacturonase - Pectin Layase
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)

30. Contains the lowest content of water
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Whole Milk
Daminozide

31. How many carbon atoms are there in the fatty acid myristic acid?
Carrageenan
They act as catalysts - speeding the polymerization of acrylamide.
Orange Juice
14

32. Are sorbitol and mannitol sweet?
Yes
Orange Juice
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
It explodes

33. What does HLB stand for and What does a high and low HLB value indicate?
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.
Polyphenols
NaCl (it dissociated to a 2M solution)
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.

34. Name 2 heat stable enzymes in food that are important to the quality of aseptic products.
DNA transferred by cell to cell contact (bacterial sex).
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
pH 3-5
Emulsification

35. 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
Yellow
Gliadins and Glutenins
.05

36. Name two enzymes that are involved in softening fruits.
Four
Anomeric
Pectin Esterase - Polygalacturonase - Pectin Layase
Parabens

37. What is the acid present in fish oil?
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Sweet - Salty - Sour - and Bitter
Olive Green
Arachidonic Acid

38. What is catalase?
An enzyme that converts hydrogen peroxide to water plus oxygen.
Thamautin
Oil in Water
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.

39. Name three factors useful in controlling enzyme activity.
Milk
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Troponins and Tropomyosin
Corn- Lysine - Potato-Methionine - Green Peas-Methionine

40. What are the three main steps in the autooxidation of lipids?
Anthocyanins
Initiation - Propagation - Termination
Fatty Acid and Alcohol
Capsaicin

41. Name the strongest biochemical bond and the weakest biochemical bond.
Non-protein nitrogen
Lipid oxidation
Covalent (strongest) and Hydrophobic (Weakest)
Polyphenoloxidase

42. Name 5 chelating agents used in the food industry.
Bright green
The speed of a molecule is proportional to the surrounding voltage gradient.
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.

43. How does HPLC differ from FPLC?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Ascorbic Acid and Citric Acid
HPLC has higher pressure than FPLC
Emulsoids

44. What are the three stages of oxidative rancidity?
Degradation of protein and production of acid from sugar at the same time.
pH below positive charge; pH at no charge; pH above negative charge
Four
Initiation - Propagation - and Termination

45. Waxes are composed of what two basic chemical entities?
Daminozide
Non-protein nitrogen
Erythorbic Acid
Fatty Acid (Ester linked) to Fatty Alcohol

46. What charge will a protein have when the pH of its solution is below at - and above its pKa?
No
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
pH below positive charge; pH at no charge; pH above negative charge

47. Name three effects of protein denaturation.
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
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).
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

48. What enzyme is most responsible for browning bananas?
Polyphenol Oxidase
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Four
RNA transcribed to DNA

49. What is the Peroxide Value a measure of?
Prolamines
Sweet - Salty - Sour - and Bitter
Fat Oxidation
Sodium chloride reduces foam stability and sucrose improves foam stability.

50. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
Onions ( or leeks)
They act as catalysts - speeding the polymerization of acrylamide.
Prolamines
Thermus Aqauticus