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 4 advantages of using enzymes in food processing.
RNA transcribed to DNA
Sodium chloride reduces foam stability and sucrose improves foam stability.
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
Carmelization and Maillard

2. What does the 'c' stand for in the equation E=mc2?
Racemic Mixture
Pectin methyl esterase or galacturonase
Speed of Light
No

3. Name a naturally occurring protein sweetener.
Olive Green
Thamautin
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Erythorbic Acid

4. What are the limiting amino acids in corn - potato - and green peas?
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Capsaicin
Yes

5. What is the acid present in fish oil?
Arachidonic Acid
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Browning of freshly cut surfaces of fruits and vegetables.
Erythorbic Acid

6. What is the acid present in fish oil?
An enzyme that converts hydrogen peroxide to water plus oxygen.
Gossypol (it is removed during the oil refining process)
Arachidonic Acid
Daminozide

7. What is the enzyme responsible for browning in apples and lettuce?
The speed of a molecule is proportional to the surrounding voltage gradient.
Fatty Acid (Ester linked) to Fatty Alcohol
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Polyphenol Oxidase

8. What is an isomer that is cheaper than Vitamin C?
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Lipid oxidation
Nucleation or crystal formation and crystal growth.
Erythorbic Acid

9. Q What reaction does the enzyme 'reverse transcriptase' catalyze?
Non-protein nitrogen
Pheophytia does not have magnesium in porphyrin ring.
Browning of freshly cut surfaces of fruits and vegetables.
RNA transcribed to DNA

10. Alar is the trade name for what chemical compound?
Initiation - Propagation - and Termination
Onions ( or leeks)
Daminozide
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces

11. What is surimi?
A concentrate of microfibrillar proteins of fish muscle.
Aspartic Acid and Phenylalanine
Non-protein nitrogen
Pectins

12. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
They act as catalysts - speeding the polymerization of acrylamide.
NaCl (it dissociated to a 2M solution)
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.
Corn- Lysine - Potato-Methionine - Green Peas-Methionine

13. What name is given to the small circular DNA molecules that carry genetic information independently of the main bacterial chromosome?
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Fatty Acid and Alcohol
Plasmids
Carmelization and Maillard

14. What are the three stages of oxidative rancidity?
Onions ( or leeks)
Initiation - Propagation - and Termination
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Carmelization and Maillard

15. Name three nonpolar polar - and charged amino acids.
Polyphenoloxidase
14
Prolamines
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)

16. What does Reichert-Meissert Number measure?
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Whole Milk
Primary butyric acid also caproic acid.
Anthocyanins

17. At what pH is benzoic acid most effective?
pH 3-5
Troponins and Tropomyosin
.05 M HCL
Fatty Acid (Ester linked) to Fatty Alcohol

18. In what food is butyric acid typically found?
.05 M HCL
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Milk
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.

19. Name 5 chelating agents used in the food industry.
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Onions ( or leeks)
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.

20. What is catalase?
No
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
An enzyme that converts hydrogen peroxide to water plus oxygen.
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.

21. In the enzyme Taq Polymerase What does Taq stand for?
Thermus Aqauticus
Olive Green
Thickener in foods
Daminozide

22. What are the three main steps in the autooxidation of lipids?
Lipase
Initiation - Propagation - Termination
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Negative log of the hydrogen concentration (mol/l).

23. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
Onions ( or leeks)
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Cis
Fat Oxidation

24. Peptide bond formation results in the formation of what secondary compound?
1 - 3 - 7-trimethylxanthine
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Water
Anomeric

25. What is the common name for 9 12 - cis-cis-octa dienoic acid?
Sweet - Salty - Sour - and Bitter
Covalent (strongest) and Hydrophobic (Weakest)
Linoleic Acid
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents

26. What metabolic disorder prevents conversion of phenulalanine to tyrosine by normal metabolic pathways?
Thermus Aqauticus
Gliadins and Glutenins
Phenylketonuria
Racemic Mixture

27. What metabolic end product does the Voges-Proskauer test detect?
Sucrose
Linoleic Acid
Acetoin
Orange Juice

28. Is a disaccharide
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Sucrose
Yes
45% - 52% - 90%

29. What enzyme is most responsible for browning bananas?
Polyphenol Oxidase
Plasmids
Troponins and Tropomyosin
45% - 52% - 90%

30. What is the movement of molecules through a semi permeable membrane from a region of low to high solute concentration called?
Carmelization and Maillard
Osmosis
Nucleation or crystal formation and crystal growth.
Lycopenes

31. How many carbon atoms and how many double bonds are there in arachidonic acid?
Glycosides of anthocyanidins
20 carbons and 4 double bonds
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Pectins

32. What are the primary secondary - tertiary - and quaternary structures?
Pheophytia does not have magnesium in porphyrin ring.
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
No
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.

33. 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
Thickener in foods
pH below positive charge; pH at no charge; pH above negative charge
Fatty Acid and Alcohol

34. What is the movement of molecules through a semi permeable membrane from a region of low to high solute concentration called?
Initiation - Propagation - Termination
20 carbons and 4 double bonds
Osmosis
Milk

35. What is the major color compound in tomatoes?
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Lycopenes
D: None of the above
Yes

36. If the absorption of a sample is being determined spectrophotometrically at 420 nm what color is the sample?
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
Fructose
Yellow

37. What does the saponification value measure and how is it measured?
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
NaCl (it dissociated to a 2M solution)
Carmelization and Maillard
Carrageenan

38. What compounds oxidize to form brown color in fruits and vegetables?
Polyphenols
Pheophytin forms
Thickener in foods
Milk

39. What is the structural difference between chlorophyll and chlocophyllide?
Lipase
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
Chlocophyllide does not have a phytoltail
Primary butyric acid also caproic acid.

40. If oxygen attacks an unsaturated fatty acids at the double bond What is the resultant product?
Monosodium Glutamate
Two aldehydes
Linoleic Acid
Polyphenol Oxidase

41. 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
Speed of Light
Browning of freshly cut surfaces of fruits and vegetables.
Monosodium Glutamate
Pheophytin forms

42. Will lipid oxidation be higher at a water activity of .05 or .5?
.05
1 - 3 - 7-trimethylxanthine
Carrageenan
Thamautin

43. An emulsifier with a high hydrophilic-lipophilic balance (HLB) value would promote which type of emulsion: oil in water or water in oil?
Polyphenoloxidase
Gossypol (it is removed during the oil refining process)
Oil in Water
Fatty Acid (Ester linked) to Fatty Alcohol

44. During freezing What are the two stages in the crystallization process?
It explodes
Phenylketonuria
Nucleation or crystal formation and crystal growth.
.05

45. What metabolic end product does the Voges-Proskauer test detect?
Acetoin
Milk
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)

46. What chemical compound is responsible for the 'hot' principle of jalepeno peppers?
Pectin Esterase
Lipid oxidation
Capsaicin
Ammonia - Water - Carbon Dioxide

47. What is the protein efficiency ratio (PER) of casein?
Sweet - Salty - Sour - and Bitter
Cis
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
2.5

48. What two common compounds are used together as an antioxidative system?
Tryptophan
Ascorbic Acid and Citric Acid
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
pH 3-5

49. Alar is the trade name for what chemical compound?
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Water
Pectin methyl esterase or galacturonase
Daminozide

50. What is the fundamental driving of electrophoresis?
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Daminozide
The speed of a molecule is proportional to the surrounding voltage gradient.
It explodes