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 is the acid present in fish oil?
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Polyphenols
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Arachidonic Acid

2. Peptide bond formation results in the formation of what secondary compound?
Sweet - Salty - Sour - and Bitter
Water
No
Pectin methylesterase & polygalacturonase

3. What is an isomer that is cheaper than Vitamin C?
Erythorbic Acid
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Pectin methyl esterase or galacturonase
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.

4. Name 3 reasons it is advantageous to obtain enzymes from microorganisms.

Warning: Invalid argument supplied for foreach() in /var/www/html/basicversity.com/show_quiz.php on line 183

5. How many polypeptide chains make up an antibody?
Osmosis
Phenylketonuria
Speed of Light
Four

6. What two common compounds are used together as an antioxidative system?
Erythorbic Acid
Ascorbic Acid and Citric Acid
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Fructose

7. What pigment was first designated as anthocyanins?
Blue pigment in flowers
Olive Green
Bright green
Ascorbic Acid and Citric Acid

8. What is the fundamental driving of electrophoresis?
Onions ( or leeks)
Olive Green
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
The speed of a molecule is proportional to the surrounding voltage gradient.

9. What enzyme causes hyrolytic rancidity in milk?
Sweet - Salty - Sour - and Bitter
45% - 52% - 90%
Lipase
Daminozide

10. What does the saponification value measure and how is it measured?
Browning of freshly cut surfaces of fruits and vegetables.
Fatty Acid and Alcohol
Oil in Water
Number of fatty acids present; mg KOH needed to saponify 1 g fat.

11. At low water activity What is the main deteriorative concern?
Lipid oxidation
.05
Thermus Aqauticus
Sodium bicarbonate generates CO2

12. A) Is the major component of most foods.B) Controls shelf-life or storage capabilityC) Regulates chemical and microbiological reactionsD) All of the above
Water
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Plasmids
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).

13. What charge will a protein have when the pH of its solution is below at - and above its pKa?
Thermus Aqauticus
pH below positive charge; pH at no charge; pH above negative charge
Primary butyric acid also caproic acid.
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.

14. What ketohexose is most significant to food chemists?
Fatty Acid and Alcohol
No
Fructose
RNA transcribed to DNA

15. Name the three positively charged amino acids.
Troponins and Tropomyosin
pH 3-5
HPLC has higher pressure than FPLC
Lysine - Arginine - and Histidine

16. What degradative enzyme causes browning in apples - pears - bananas - and peaches?
Polyphenoloxidase
Browning of freshly cut surfaces of fruits and vegetables.
45% - 52% - 90%
Milk

17. What is catalase?
A concentrate of microfibrillar proteins of fish muscle.
An enzyme that converts hydrogen peroxide to water plus oxygen.
Two aldehydes
Troponins and Tropomyosin

18. How do sodium chloride and sucrose affect foam stability?
1 - 3 - 7-trimethylxanthine
Carmelization and Maillard
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Sodium chloride reduces foam stability and sucrose improves foam stability.

19. What does the iodine value measure and how is it measured?
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Orange Juice
Linoleic Acid

20. 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
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.
They act as catalysts - speeding the polymerization of acrylamide.
Browning of freshly cut surfaces of fruits and vegetables.
Gliadins and Glutenins

21. 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?
Sodium bicarbonate generates CO2
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
.05 M HCL
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)

22. Name two enzymes that are involved in softening fruits.
Lipase
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Oil in Water
Pectin Esterase - Polygalacturonase - Pectin Layase

23. Food additive that could be used to prevent cocoa particles from settling in chocolate milk
Carrageenan
Carmelization and Maillard
Tryptophan
2.5

24. What are the three main steps in the autooxidation of lipids?
Ascorbic Acid and Citric Acid
Pheophytin forms
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.
Initiation - Propagation - Termination

25. Name three nonpolar polar - and charged amino acids.
Pectin Esterase
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
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)

26. What would be a safe processing time for heat processing green beans in a boiling water bath? A. 30 minutes B. 300 minutes C. Depends on the size of the food container D. None of the above
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
D: None of the above
20 carbons and 4 double bonds
Fatty Acid and Alcohol

27. What are the limiting amino acids in corn - potato - and green peas?
Erythorbic Acid
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Sodium bicarbonate generates CO2
Osmosis

28. Name the two components that comprise the relaxing factor in muscle fibers.
Troponins and Tropomyosin
Lycopenes
Pectins
Olive Green

29. A chlorophyll molecule reacting with magnesium exhibits what shade of green?
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Bright green
.05
14

30. What is the name of the degradation compound of chlorophyll?
Fatty Acid (Ester linked) to Fatty Alcohol
Phenophylin
Yellow
Gliadins and Glutenins

31. What charge will a protein have when the pH of its solution is below at - and above its pKa?
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Polyphenol Oxidase
Four
pH below positive charge; pH at no charge; pH above negative charge

32. What are the three stages of oxidative rancidity?
Lycopenes
Gliadins and Glutenins
Initiation - Propagation - and Termination
It explodes

33. What are the four basic flavors perceived by the tongue?
Sweet - Salty - Sour - and Bitter
Lipid oxidation
45% - 52% - 90%
V=IR and P=VI or I x I x are

34. Name two main gluten proteins.
Fructose
Gliadins and Glutenins
Fatty Acid (Ester linked) to Fatty Alcohol
Lipid oxidation

35. What enzyme is most responsible for browning bananas?
Capsaicin
Thermus Aqauticus
Plasmids
Polyphenol Oxidase

36. What is the winterization process for an oil?
pH 3-5
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Milk
45% - 52% - 90%

37. If the absorption of a sample is being determined spectrophotometrically at 420 nm what color is the sample?
Milk
Negative log of the hydrogen concentration (mol/l).
They act as catalysts - speeding the polymerization of acrylamide.
Yellow

38. What is surimi?
Polyphenols
Chlocophyllide does not have a phytoltail
Parabens
A concentrate of microfibrillar proteins of fish muscle.

39. What is the main class of color compounds found in raspberries?
Emulsoids
Pectin methylesterase & polygalacturonase
Arachidonic Acid
Anthocyanins

40. How is pH defined?
An enzyme that converts hydrogen peroxide to water plus oxygen.
Chitin
Negative log of the hydrogen concentration (mol/l).
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.

41. Name 3 factors influencing the rate of lipid oxidation in foods.
Pectin Esterase - Polygalacturonase - Pectin Layase
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Nucleation or crystal formation and crystal growth.

42. What is the common name for 9 12 - cis-cis-octa dienoic acid?
Linoleic Acid
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
Covalent (strongest) and Hydrophobic (Weakest)

43. What is catalase?
.05
pH below positive charge; pH at no charge; pH above negative charge
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
An enzyme that converts hydrogen peroxide to water plus oxygen.

44. At low water activity What is the main deteriorative concern?
Lipid oxidation
Fructose
NaCl (it dissociated to a 2M solution)
Acetoin

45. What is surimi?
A concentrate of microfibrillar proteins of fish muscle.
Glycosides of anthocyanidins
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Plasmids

46. Name a naturally occurring protein sweetener.
Bright green
Speed of Light
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Thamautin

47. What is the Peroxide Value a measure of?
Fat Oxidation
Polyphenols
Racemic Mixture
Pectin Esterase - Polygalacturonase - Pectin Layase

48. Name 4 advantages of using enzymes in food processing.
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
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
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
An enzyme that converts hydrogen peroxide to water plus oxygen.

49. Which two amino acids is the aspartame derived from?
Polyphenol Oxidase
Lamellar; Hexagonal I - II; Cubic
Aspartic Acid and Phenylalanine
Orange Juice

50. What does Acid Degree Value measure and how is it measured?
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Lipase
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Two aldehydes