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. A chlorophyll molecule reacting with hydrogen exhibits what shade of green?
Browning of freshly cut surfaces of fruits and vegetables.
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.
Olive Green
Erythorbic Acid

2. What is surimi?
A concentrate of microfibrillar proteins of fish muscle.
Water
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
45% - 52% - 90%

3. How is pH defined?
No
.05
Negative log of the hydrogen concentration (mol/l).
Erythorbic Acid

4. 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)
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
DNA transferred by cell to cell contact (bacterial sex).
Browning of freshly cut surfaces of fruits and vegetables.

5. What are the limiting amino acids in corn - potato - and green peas?
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Pectin methylesterase & polygalacturonase
Thamautin
Acsulfame-K - Saccharin - Cyclamate - Aspartame

6. Which amino acid has the greatest molecular weight: tryptophan or tyrosine?
Oil in Water
Erythorbic Acid
14
Tryptophan

7. What does the acronym NPN stand for?
Chlocophyllide does not have a phytoltail
Pheophytin forms
Non-protein nitrogen
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.

8. What are two common reducing agents that break disulfide bonds in proteins?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
2.5
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
An enzyme that converts hydrogen peroxide to water plus oxygen.

9. What name is given to the small circular DNA molecules that carry genetic information independently of the main bacterial chromosome?
Plasmids
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Anomeric
Gliadins and Glutenins

10. During freezing What are the two stages in the crystallization process?
Nucleation or crystal formation and crystal growth.
RNA transcribed to DNA
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.

11. What metabolic disorder prevents conversion of phenulalanine to tyrosine by normal metabolic pathways?
pH 3-5
Pectin methyl esterase or galacturonase
Phenylketonuria
HPLC has higher pressure than FPLC

12. Does kosmotrophil ion discourage water structure?
Non-protein nitrogen
Anthocyanins
Phenylketonuria
No

13. Give one word for a carbon atom involved in hemiacetal or acetal formation.
Anomeric
45% - 52% - 90%
1 - 3 - 7-trimethylxanthine
Covalent (strongest) and Hydrophobic (Weakest)

14. What is the main class of color compounds found in raspberries?
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Anthocyanins
Thickener in foods
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants

15. What is the protein efficiency ratio (PER) of casein?
2.5
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.
Bright green
Lipid oxidation

16. How does HPLC differ from FPLC?
HPLC has higher pressure than FPLC
Bright green
Monosodium Glutamate
1 - 3 - 7-trimethylxanthine

17. What is an isomer that is cheaper than Vitamin C?
Non-protein nitrogen
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Erythorbic Acid
ERH=100 x Aw

18. Name three compounds capable of poisoning the catalyst during commercial hydrogenation.
Chlocophyllide does not have a phytoltail
Bright green
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
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.

19. Name two reasons why fats are hydrogenated.
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
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.
Polyphenol Oxidase

20. What does HLB stand for and What does a high and low HLB value indicate?
Lamellar; Hexagonal I - II; Cubic
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.
Lycopenes
Phenylketonuria

21. Name a naturally occurring protein sweetener.
Thamautin
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
HPLC has higher pressure than FPLC
Pectin Esterase - Polygalacturonase - Pectin Layase

22. What are colloids that are stabilized by a layer of solvation called?
Fat Oxidation
Emulsoids
Daminozide
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.

23. 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
Covalent (strongest) and Hydrophobic (Weakest)
Browning of freshly cut surfaces of fruits and vegetables.
V=IR and P=VI or I x I x are
Cis

24. Name 3 factors influencing the rate of lipid oxidation in foods.
Thermus Aqauticus
Sucrose
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants

25. Define molarity molality - and normality.
An enzyme that converts hydrogen peroxide to water plus oxygen.
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Initiation - Propagation - and Termination
Plasmids

26. At low water activity What is the main deteriorative concern?
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.
Ammonia - Water - Carbon Dioxide
Whole Milk
Lipid oxidation

27. Name 3 factors influencing the consistency of commercial fats.
It explodes
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Cis
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)

28. What is the protein efficiency ratio (PER) of casein?
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Ascorbic Acid and Citric Acid
2.5
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.

29. What is the common name for 9 12 - cis-cis-octa dienoic acid?
Linoleic Acid
Glycosides of anthocyanidins
Ammonia - Water - Carbon Dioxide
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.

30. What is the winterization process for an oil?
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Prolamines
Chlocophyllide does not have a phytoltail
Carrageenan

31. What does the acronym NPN stand for?
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Capsaicin
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Non-protein nitrogen

32. Name the strongest biochemical bond and the weakest biochemical bond.
An enzyme that converts hydrogen peroxide to water plus oxygen.
Covalent (strongest) and Hydrophobic (Weakest)
Polyphenol Oxidase
Primary butyric acid also caproic acid.

33. What are the limiting amino acids in corn - potato - and green peas?
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter 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
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.

34. Name the three positively charged amino acids.
Gossypol (it is removed during the oil refining process)
Primary butyric acid also caproic acid.
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Lysine - Arginine - and Histidine

35. What are the four basic flavors perceived by the tongue?
Pheophytia does not have magnesium in porphyrin ring.
Lycopenes
Daminozide
Sweet - Salty - Sour - and Bitter

36. What charge will a protein have when the pH of its solution is below at - and above its pKa?
Anthocyanins
Negative log of the hydrogen concentration (mol/l).
pH below positive charge; pH at no charge; pH above negative charge
Thickener in foods

37. What effect would the addition of sodium bicarbonate have to chocolate?
Fat Oxidation
Gossypol (it is removed during the oil refining process)
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).

38. What pigment was first designated as anthocyanins?
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Blue pigment in flowers
1 - 3 - 7-trimethylxanthine

39. What is a polymorphism?
Oil in Water
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Primary butyric acid also caproic acid.

40. What is the fundamental driving of electrophoresis?
Polyphenols
The speed of a molecule is proportional to the surrounding voltage gradient.
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Phenophylin

41. What does the saponification value measure and how is it measured?
Initiation - Propagation - Termination
Blue pigment in flowers
Gliadins and Glutenins
Number of fatty acids present; mg KOH needed to saponify 1 g fat.

42. How does ERH relate to water activity?
Gossypol (it is removed during the oil refining process)
14
Lamellar; Hexagonal I - II; Cubic
ERH=100 x Aw

43. What does the 'c' stand for in the equation E=mc2?
Cis
Sucrose
Speed of Light
Milk

44. What does the iodine value measure and how is it measured?
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Thickener in foods
Nucleation or crystal formation and crystal growth.

45. Peptide bond formation results in the formation of what secondary compound?
Ascorbic Acid and Citric Acid
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Water
Capsaicin

46. What enzyme is most responsible for browning bananas?
Pectin Esterase - Polygalacturonase - Pectin Layase
Negative log of the hydrogen concentration (mol/l).
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.
Polyphenol Oxidase

47. Give one word for a carbon atom involved in hemiacetal or acetal formation.
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.
Anomeric
Tryptophan
Thickener in foods

48. 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)
Ammonia - Water - Carbon Dioxide
Oil in Water
20 carbons and 4 double bonds

49. Name two enzymes that are involved in softening fruits.
Thamautin
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Pectin Esterase - Polygalacturonase - Pectin Layase
20 carbons and 4 double bonds

50. What degradative enzyme causes browning in apples - pears - bananas - and peaches?
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Polyphenoloxidase
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Thickener in foods