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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. 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
Orange Juice
Water
Browning of freshly cut surfaces of fruits and vegetables.
Pheophytin forms
2. If the absorption of a sample is being determined spectrophotometrically at 420 nm what color is the sample?
Cis
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Lysine - Arginine - and Histidine
Yellow
3. What are the three stages of oxidative rancidity?
Polyphenols
Plasmids
Initiation - Propagation - and Termination
14
4. What is the chemical nature of anthocyanins?
.05
Sucrose
Glycosides of anthocyanidins
Anomeric
5. Give one word for a carbon atom involved in hemiacetal or acetal formation.
Thamautin
Anomeric
V=IR and P=VI or I x I x are
Racemic Mixture
6. What is the structural difference between chlorophyll and pheophytia?
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.
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Pheophytia does not have magnesium in porphyrin ring.
7. Name the two components that comprise the relaxing factor in muscle fibers.
Whole Milk
Emulsoids
Troponins and Tropomyosin
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
8. How does HPLC differ from FPLC?
Sweet - Salty - Sour - and Bitter
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
HPLC has higher pressure than FPLC
9. What enzyme is most responsible for browning bananas?
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Polyphenol Oxidase
Chlocophyllide does not have a phytoltail
10. Food additive that could be used to prevent cocoa particles from settling in chocolate milk
The speed of a molecule is proportional to the surrounding voltage gradient.
Carrageenan
Fatty Acid and Alcohol
A concentrate of microfibrillar proteins of fish muscle.
11. Q What reaction does the enzyme 'reverse transcriptase' catalyze?
RNA transcribed to DNA
2.5
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Parabens
12. In what food is butyric acid typically found?
Plasmids
Lysine - Arginine - and Histidine
Milk
Linoleic Acid
13. Which two amino acids is the aspartame derived from?
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Anthocyanins
Aspartic Acid and Phenylalanine
14. What are the limiting amino acids in corn - potato - and green peas?
Pectin Esterase
Glycosides of anthocyanidins
Polyphenol Oxidase
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
15. What does Acid Degree Value measure and how is it measured?
Lamellar; Hexagonal I - II; Cubic
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Carrageenan
16. The undesirable clarification of orange juice or tomato juice (precipitation of pulp) is caused by what enzymes?
Lysine - Arginine - and Histidine
Pectin methyl esterase or galacturonase
Emulsoids
It explodes
17. In the enzyme Taq Polymerase What does Taq stand for?
Tryptophan
Thermus Aqauticus
D: None of the above
Tryptophan
18. 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.
Degradation of protein and production of acid from sugar at the same time.
It explodes
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
19. What are the limiting amino acids in corn - potato - and green peas?
.05
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Lysine - Arginine - and Histidine
Sodium bicarbonate generates CO2
20. Peptide bond formation results in the formation of what secondary compound?
Water
pH 3-5
Four
An enzyme that converts hydrogen peroxide to water plus oxygen.
21. What compounds oxidize to form brown color in fruits and vegetables?
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
RNA transcribed to DNA
Pectin Esterase - Polygalacturonase - Pectin Layase
Polyphenols
22. What is the name of the structural carbohydrate found in lobsters crab - shellfish - and insects?
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
Phenylketonuria
Polyphenoloxidase
Chitin
23. What is the fundamental driving of electrophoresis?
The speed of a molecule is proportional to the surrounding voltage gradient.
Water
Fatty Acid (Ester linked) to Fatty Alcohol
Pectin methyl esterase or galacturonase
24. What is surimi?
Lipid oxidation
A concentrate of microfibrillar proteins of fish muscle.
NaCl (it dissociated to a 2M solution)
Fatty Acid (Ester linked) to Fatty Alcohol
25. Which of these foods is not appropriate to this list? A) Salami B) Yogurt C) Orange Juice D) Beer
Speed of Light
Daminozide
Sodium chloride reduces foam stability and sucrose improves foam stability.
Orange Juice
26. In genetics What is conjugation?
.05
pH 3-5
DNA transferred by cell to cell contact (bacterial sex).
Emulsification
27. What is the name of the structural carbohydrate found in lobsters crab - shellfish - and insects?
Speed of Light
Prolamines
Arachidonic Acid
Chitin
28. What is the chemical nature of anthocyanins?
Anomeric
Erythorbic Acid
Glycosides of anthocyanidins
Onions ( or leeks)
29. Name 4 advantages of using enzymes in food processing.
Osmosis
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
Gliadins and Glutenins
pH below positive charge; pH at no charge; pH above negative charge
30. A chlorophyll molecule reacting with magnesium exhibits what shade of green?
Phenophylin
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Bright green
Four
31. What is Ohm's Law and What is Power Equation?
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Ammonia - Water - Carbon Dioxide
V=IR and P=VI or I x I x are
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
32. What are the primary secondary - tertiary - and quaternary structures?
Thermus Aqauticus
Monosodium Glutamate
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.
Chlocophyllide does not have a phytoltail
33. Which will be coldest at its freezing point: 1M dispersion of amylose 1M solution of NaCl - distilled water - or 1M solution of sucrose?
Arachidonic Acid
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.
NaCl (it dissociated to a 2M solution)
HPLC has higher pressure than FPLC
34. What is the structural difference between chlorophyll and chlocophyllide?
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Chlocophyllide does not have a phytoltail
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
35. What name is given to the small circular DNA molecules that carry genetic information independently of the main bacterial chromosome?
Plasmids
Thermus Aqauticus
Yes
Anomeric
36. Name a commonly used household chemical leavening agent and the gas it generates.
No
Sodium bicarbonate generates CO2
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
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.
37. What are the fructose contents in commercial HFCS products.
45% - 52% - 90%
.05 M HCL
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Acsulfame-K - Saccharin - Cyclamate - Aspartame
38. What is the major color compound in tomatoes?
Thamautin
Lycopenes
Daminozide
Fructose
39. If oxygen attacks an unsaturated fatty acids at the double bond What is the resultant product?
Two aldehydes
HPLC has higher pressure than FPLC
Lipase
Pectin Esterase
40. 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
Erythorbic Acid
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Water
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
41. How is pH defined?
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
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.
Negative log of the hydrogen concentration (mol/l).
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.
42. Name two non-enzymatic browning reactions.
Carmelization and Maillard
They act as catalysts - speeding the polymerization of acrylamide.
Pectin Esterase
Initiation - Propagation - Termination
43. What does the saponification value measure and how is it measured?
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Yellow
Initiation - Propagation - and Termination
44. What is an isomer that is cheaper than Vitamin C?
Erythorbic Acid
Daminozide
Negative log of the hydrogen concentration (mol/l).
Lamellar; Hexagonal I - II; Cubic
45. What are colloids that are stabilized by a layer of solvation called?
Emulsoids
Fructose
Polyphenol Oxidase
Ammonia - Water - Carbon Dioxide
46. Name three nonpolar polar - and charged amino acids.
DNA transferred by cell to cell contact (bacterial sex).
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Carrageenan
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
47. What metabolic end product does the Voges-Proskauer test detect?
Racemic Mixture
Acetoin
Yellow
Daminozide
48. How do sodium chloride and sucrose affect foam stability?
Sodium chloride reduces foam stability and sucrose improves foam stability.
Plasmids
Phenophylin
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
49. During freezing What are the two stages in the crystallization process?
45% - 52% - 90%
Sodium bicarbonate generates CO2
Carmelization and Maillard
Nucleation or crystal formation and crystal growth.
50. Name 3 physical agents capable of denaturing proteins.
The speed of a molecule is proportional to the surrounding voltage gradient.
Thickener in foods
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces