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Test your basic knowledge |
Food Chemistry
Start Test
Study First
Subjects
:
engineering
,
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. 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?
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.
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Pheophytia does not have magnesium in porphyrin ring.
2. A chlorophyll molecule reacting with magnesium exhibits what shade of green?
Yellow
Bright green
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Monosodium Glutamate
3. An emulsifier with a high hydrophilic-lipophilic balance (HLB) value would promote which type of emulsion: oil in water or water in oil?
Fatty Acid (Ester linked) to Fatty Alcohol
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Oil in Water
Gossypol (it is removed during the oil refining process)
4. What does the 'c' stand for in the equation E=mc2?
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Speed of Light
Initiation - Propagation - and Termination
Bright green
5. What happens to chlorophyll on heating?
Pheophytin forms
Phenophylin
Onions ( or leeks)
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
6. In what food is butyric acid typically found?
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Water
Milk
Phenophylin
7. What are the four basic flavors perceived by the tongue?
Sweet - Salty - Sour - and Bitter
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
pH 3-5
No
8. What is the winterization process for an oil?
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
9. Name the three positively charged amino acids.
Lysine - Arginine - and Histidine
Monosodium Glutamate
Onions ( or leeks)
Olive Green
10. 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
D: None of the above
Linoleic Acid
Polyphenols
Whole Milk
11. Name three compounds capable of poisoning the catalyst during commercial hydrogenation.
Primary butyric acid also caproic acid.
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
.05
Linoleic Acid
12. Name 5 chelating agents used in the food industry.
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Carmelization and Maillard
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
13. Name the two components that comprise the relaxing factor in muscle fibers.
Troponins and Tropomyosin
Pectin Esterase
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Pheophytia does not have magnesium in porphyrin ring.
14. What is the structural difference between chlorophyll and pheophytia?
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Prolamines
Pheophytia does not have magnesium in porphyrin ring.
Negative log of the hydrogen concentration (mol/l).
15. What metabolic disorder prevents conversion of phenulalanine to tyrosine by normal metabolic pathways?
Sodium bicarbonate generates CO2
D: None of the above
Phenylketonuria
DNA transferred by cell to cell contact (bacterial sex).
16. Name two non-enzymatic browning reactions.
Carmelization and Maillard
Nucleation or crystal formation and crystal growth.
1 - 3 - 7-trimethylxanthine
Chlocophyllide does not have a phytoltail
17. What name is given to the small circular DNA molecules that carry genetic information independently of the main bacterial chromosome?
Plasmids
Anomeric
Browning of freshly cut surfaces of fruits and vegetables.
Whole Milk
18. 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
Pectin Esterase
Polyphenols
Browning of freshly cut surfaces of fruits and vegetables.
ERH=100 x Aw
19. What is the fundamental driving of electrophoresis?
Ascorbic Acid and Citric Acid
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
The speed of a molecule is proportional to the surrounding voltage gradient.
It explodes
20. What is the name of the structural carbohydrate found in lobsters crab - shellfish - and insects?
Chitin
Polyphenoloxidase
Racemic Mixture
Fatty Acid (Ester linked) to Fatty Alcohol
21. What does the saponification value measure and how is it measured?
Sweet - Salty - Sour - and Bitter
Pheophytia does not have magnesium in porphyrin ring.
Emulsification
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
22. What ketohexose is most significant to food chemists?
Lycopenes
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Thermus Aqauticus
Fructose
23. Will lipid oxidation be higher at a water activity of .05 or .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.
Two aldehydes
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
.05
24. What are soluble polymers of anhydro-galacturonic acid and its esters called?
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
Pectins
Yellow
14
25. What is surimi?
Erythorbic Acid
Nucleation or crystal formation and crystal growth.
A concentrate of microfibrillar proteins of fish muscle.
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
26. What does Acid Degree Value measure and how is it measured?
Emulsification
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
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.
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
27. What are the limiting amino acids in corn - potato - and green peas?
Anomeric
14
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Water
28. What charge will a protein have when the pH of its solution is below at - and above its pKa?
pH below positive charge; pH at no charge; pH above negative charge
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
Polyphenols
Olive Green
29. In the enzyme Taq Polymerase What does Taq stand for?
Thermus Aqauticus
Emulsification
Chlocophyllide does not have a phytoltail
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.
30. Name the most common functional property of phospholipids in food systems.
.05
Emulsification
ERH=100 x Aw
RNA transcribed to DNA
31. What metabolic disorder prevents conversion of phenulalanine to tyrosine by normal metabolic pathways?
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Initiation - Propagation - and Termination
Phenylketonuria
Prolamines
32. Name three effects of protein denaturation.
Nucleation or crystal formation and crystal growth.
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Acetoin
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
33. At low water activity What is the main deteriorative concern?
45% - 52% - 90%
Polyphenol Oxidase
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Lipid oxidation
34. Name three compounds capable of poisoning the catalyst during commercial hydrogenation.
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
It explodes
Orange Juice
35. What does the 'c' stand for in the equation E=mc2?
Speed of Light
Plasmids
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Chitin
36. Peptide bond formation results in the formation of what secondary compound?
Lysine - Arginine - and Histidine
Water
Pheophytin forms
Four
37. Name 2 heat stable enzymes in food that are important to the quality of aseptic products.
pH 3-5
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Four
Non-protein nitrogen
38. What is the protein efficiency ratio (PER) of casein?
pH 3-5
Pheophytia does not have magnesium in porphyrin ring.
Lycopenes
2.5
39. Contains the lowest content of water
Whole Milk
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
40. What are the three main steps in the autooxidation of lipids?
Initiation - Propagation - Termination
Capsaicin
Blue pigment in flowers
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
41. Which amino acid has the greatest molecular weight: tryptophan or tyrosine?
Carrageenan
Negative log of the hydrogen concentration (mol/l).
Sodium bicarbonate generates CO2
Tryptophan
42. What enzyme causes hyrolytic rancidity in milk?
Polyphenoloxidase
Lipase
Lycopenes
.05 M HCL
43. Name two non-enzymatic browning reactions.
Plasmids
Carmelization and Maillard
Daminozide
It explodes
44. Name 3 chemical agents capable of denaturing proteins.
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Whole Milk
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Olive Green
45. What chemical compound is responsible for the 'hot' principle of jalepeno peppers?
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Capsaicin
.05
Tryptophan
46. What is a polymorphism?
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Prolamines
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Thickener in foods
47. What is the name of the structural carbohydrate found in lobsters crab - shellfish - and insects?
Fatty Acid and Alcohol
Thermus Aqauticus
Anomeric
Chitin
48. At what pH is benzoic acid most effective?
pH 3-5
DNA transferred by cell to cell contact (bacterial sex).
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Sucrose
49. Name 3 factors influencing the rate of lipid oxidation in foods.
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
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 butyric acid also caproic acid.
14
50. The undesirable clarification of orange juice or tomato juice (precipitation of pulp) is caused by what enzymes?
They act as catalysts - speeding the polymerization of acrylamide.
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
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.
Pectin methyl esterase or galacturonase