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 factors influencing the consistency of commercial fats.
Glycosides of anthocyanidins
Four
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.

2. How many carbon atoms are there in the fatty acid myristic acid?
Phenylketonuria
Emulsoids
RNA transcribed to DNA
14

3. What are the primary secondary - tertiary - and quaternary structures?
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
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.
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Water

4. Name three factors useful in controlling enzyme activity.
Milk
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Speed of Light

5. What are the limiting amino acids in corn - potato - and green peas?
Carmelization and Maillard
Glycosides of anthocyanidins
Pectin Esterase
Corn- Lysine - Potato-Methionine - Green Peas-Methionine

6. 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)
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Linoleic Acid
Daminozide

7. What ketohexose is most significant to food chemists?
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Olive Green
Fructose
Yellow

8. Contains the lowest content of water
Whole Milk
Negative log of the hydrogen concentration (mol/l).
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Linoleic Acid

9. What metabolic end product does the Voges-Proskauer test detect?
Plasmids
Acetoin
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.
Pectin methyl esterase or galacturonase

10. What are the three stages of oxidative rancidity?
Initiation - Propagation - and Termination
Tryptophan
Primary butyric acid also caproic acid.
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.

11. A chlorophyll molecule reacting with hydrogen exhibits what shade of green?
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter 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.
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Olive Green

12. Name two main gluten proteins.
RNA transcribed to DNA
Gliadins and Glutenins
Phenylketonuria
Bright green

13. Name the three positively charged amino acids.
Lysine - Arginine - and Histidine
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Troponins and Tropomyosin
Pheophytin forms

14. What does HLB stand for and What does a high and low HLB value indicate?
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and 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.
They act as catalysts - speeding the polymerization of acrylamide.

15. Which of these foods is not appropriate to this list? A) Salami B) Yogurt C) Orange Juice D) Beer
Capsaicin
Chitin
Orange Juice
An enzyme that converts hydrogen peroxide to water plus oxygen.

16. What is the enzyme that softens tomatoes?
Primary butyric acid also caproic acid.
Racemic Mixture
Pectin Esterase
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)

17. What are 3 mesomorphic structures associated with lipids in the liquid state?
Ammonia - Water - Carbon Dioxide
DNA transferred by cell to cell contact (bacterial sex).
Lamellar; Hexagonal I - II; Cubic
Nucleation or crystal formation and crystal growth.

18. How many carbon atoms and how many double bonds are there in arachidonic acid?
20 carbons and 4 double bonds
Olive Green
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Speed of Light

19. What two common compounds are used together as an antioxidative system?
Ascorbic Acid and Citric Acid
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Monosodium Glutamate
NaCl (it dissociated to a 2M solution)

20. What does MSG stand for?
Yes
Bright green
Pheophytin forms
Monosodium Glutamate

21. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
HPLC has higher pressure than FPLC
A concentrate of microfibrillar proteins of fish muscle.
Linoleic Acid
Butter= water in oil Mayonnaise= oil in water Milk= oil in water

22. Which will be coldest at its freezing point: 1M dispersion of amylose 1M solution of NaCl - distilled water - or 1M solution of sucrose?
Carrageenan
NaCl (it dissociated to a 2M solution)
.05 M HCL
Pectins

23. Name the strongest biochemical bond and the weakest biochemical bond.
Covalent (strongest) and Hydrophobic (Weakest)
Two aldehydes
Nucleation or crystal formation and crystal growth.
Whole Milk

24. If oxygen attacks an unsaturated fatty acids at the double bond What is the resultant product?
Non-protein nitrogen
Sucrose
Initiation - Propagation - Termination
Two aldehydes

25. Waxes are composed of what two basic chemical entities?
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.
D: None of the above
Water
Fatty Acid (Ester linked) to Fatty Alcohol

26. What ketohexose is most significant to food chemists?
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
It explodes
Pectin methylesterase & polygalacturonase
Fructose

27. Which amino acid has the greatest molecular weight: tryptophan or tyrosine?
Tryptophan
Bitter
Pectins
Lysine - Arginine - and Histidine

28. What toxic pigment is found in cottonseed endosperm?
DNA transferred by cell to cell contact (bacterial sex).
Linoleic Acid
Thamautin
Gossypol (it is removed during the oil refining process)

29. What two enzymes degrade pectic substances?
Emulsoids
Racemic Mixture
Pectin methylesterase & polygalacturonase
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.

30. What two enzymes degrade pectic substances?
Cis
Erythorbic Acid
Pectin methylesterase & polygalacturonase
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.

31. What are the primary secondary - tertiary - and quaternary structures?
Daminozide
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.
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Olive Green

32. Name 2 heat stable enzymes in food that are important to the quality of aseptic products.
45% - 52% - 90%
Pheophytin forms
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.

33. How does HPLC differ from FPLC?
Fatty Acid and Alcohol
HPLC has higher pressure than FPLC
Polyphenols
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).

34. What is the name of the structural carbohydrate found in lobsters crab - shellfish - and insects?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Covalent (strongest) and Hydrophobic (Weakest)
Chitin
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.

35. 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?
20 carbons and 4 double bonds
D: None of the above
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.

36. What is the chemical nature of anthocyanins?
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)
Glycosides of anthocyanidins
It explodes

37. What is the fundamental driving of electrophoresis?
ERH=100 x Aw
The speed of a molecule is proportional to the surrounding voltage gradient.
2.5
Thickener in foods

38. What are the fructose contents in commercial HFCS products.
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
45% - 52% - 90%
Primary butyric acid also caproic 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

39. What pigment was first designated as anthocyanins?
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Phenophylin
pH 3-5
Blue pigment in flowers

40. Name two enzymes that are involved in softening fruits.
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Pectin Esterase - Polygalacturonase - Pectin Layase
Initiation - Propagation - Termination

41. What is a polymorphism?
Four
Bright green
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Cis

42. What is acid proteolysis?
NaCl (it dissociated to a 2M solution)
Degradation of protein and production of acid from sugar at the same time.
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
Sodium bicarbonate generates CO2

43. Name three nonpolar polar - and charged amino acids.
Racemic Mixture
An enzyme that converts hydrogen peroxide to water plus oxygen.
Negative log of the hydrogen concentration (mol/l).
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)

44. 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?
Whole Milk
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Whole Milk
.05 M HCL

45. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
They act as catalysts - speeding the polymerization of acrylamide.
Pheophytin forms
Fatty Acid and Alcohol

46. Name 3 factors influencing the rate of lipid oxidation in foods.
2.5
Bright green
Initiation - Propagation - Termination
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants

47. Alar is the trade name for what chemical compound?
Daminozide
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Lysine - Arginine - and Histidine
Carrageenan

48. What is surimi?
A concentrate of microfibrillar proteins of fish muscle.
14
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
Negative log of the hydrogen concentration (mol/l).

49. What is the protein efficiency ratio (PER) of casein?
Yellow
Blue pigment in flowers
Erythorbic Acid
2.5

50. Name two main gluten proteins.
Nucleation or crystal formation and crystal growth.
Gliadins and Glutenins
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.