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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. Does kosmotrophil ion discourage water structure?
Water
Pectin methylesterase & polygalacturonase
No
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
2. What pigment was first designated as anthocyanins?
Oil in Water
Blue pigment in flowers
Lipase
Pheophytin forms
3. Name 3 chemical agents capable of denaturing proteins.
Degradation of protein and production of acid from sugar at the same time.
D: None of the above
Anthocyanins
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
4. Name 5 chelating agents used in the food industry.
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
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.
5. Name two enzymes that are involved in softening fruits.
Fatty Acid and Alcohol
Pectin Esterase - Polygalacturonase - Pectin Layase
Monosodium Glutamate
Water
6. What is the main class of color compounds found in raspberries?
Phenylketonuria
Anthocyanins
An enzyme that converts hydrogen peroxide to water plus oxygen.
Browning of freshly cut surfaces of fruits and vegetables.
7. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
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)
Onions ( or leeks)
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
8. What metabolic disorder prevents conversion of phenulalanine to tyrosine by normal metabolic pathways?
Phenylketonuria
Phenophylin
Arachidonic Acid
Milk
9. An emulsifier with a high hydrophilic-lipophilic balance (HLB) value would promote which type of emulsion: oil in water or water in oil?
Gossypol (it is removed during the oil refining process)
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Oil in Water
They act as catalysts - speeding the polymerization of acrylamide.
10. What is the name of the structural carbohydrate found in lobsters crab - shellfish - and insects?
Chitin
Pectin Esterase
Carrageenan
Cis
11. What is the movement of molecules through a semi permeable membrane from a region of low to high solute concentration called?
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Oil in Water
Osmosis
Negative log of the hydrogen concentration (mol/l).
12. At what pH is benzoic acid most effective?
Degradation of protein and production of acid from sugar at the same time.
Two aldehydes
Lipase
pH 3-5
13. What is the chemical nomenclature for caffeine?
Lysine - Arginine - and Histidine
1 - 3 - 7-trimethylxanthine
Fat Oxidation
Polyphenol Oxidase
14. A) Is the major component of most foods.B) Controls shelf-life or storage capabilityC) Regulates chemical and microbiological reactionsD) All of the above
Fatty Acid (Ester linked) to Fatty Alcohol
Water
Orange Juice
Browning of freshly cut surfaces of fruits and vegetables.
15. Contains the lowest content of water
Fatty Acid (Ester linked) to Fatty Alcohol
Whole Milk
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Capsaicin
16. In the enzyme Taq Polymerase What does Taq stand for?
.05
Thermus Aqauticus
Ammonia - Water - Carbon Dioxide
Pectin methylesterase & polygalacturonase
17. What two common compounds are used together as an antioxidative system?
Polyphenol Oxidase
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Ascorbic Acid and Citric Acid
Emulsoids
18. The undesirable clarification of orange juice or tomato juice (precipitation of pulp) is caused by what enzymes?
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Pectin Esterase - Polygalacturonase - Pectin Layase
Pectin methyl esterase or galacturonase
Four
19. In genetics What is conjugation?
ERH=100 x Aw
Prolamines
Whole Milk
DNA transferred by cell to cell contact (bacterial sex).
20. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
Tryptophan
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
Bright green
They act as catalysts - speeding the polymerization of acrylamide.
21. What does Acid Degree Value measure and how is it measured?
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
No
Daminozide
Daminozide
22. Name a commonly used household chemical leavening agent and the gas it generates.
Prolamines
Sodium bicarbonate generates CO2
Emulsification
Phenophylin
23. What compounds oxidize to form brown color in 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.
Lipid oxidation
Four
Polyphenols
24. What chemical compound is responsible for the 'hot' principle of jalepeno peppers?
Polyphenol Oxidase
Lipase
Capsaicin
ERH=100 x Aw
25. What is the geometric configuration of double bonds in most natural fatty acids?
Lycopenes
Erythorbic Acid
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Cis
26. Name 3 factors influencing the consistency of commercial fats.
Primary butyric acid also caproic acid.
Pectin methylesterase & polygalacturonase
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
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.
27. What is the main class of color compounds found in raspberries?
Anthocyanins
Osmosis
Lamellar; Hexagonal I - II; Cubic
Acetoin
28. What is Carboxy-methyl cellulose often used for?
Pheophytin forms
Olive Green
Thickener in foods
pH below positive charge; pH at no charge; pH above negative charge
29. Name the three positively charged amino acids.
Gliadins and Glutenins
Sodium bicarbonate generates CO2
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Lysine - Arginine - and Histidine
30. Name three compounds capable of poisoning the catalyst during commercial hydrogenation.
Carrageenan
pH below positive charge; pH at no charge; pH above negative charge
Nucleation or crystal formation and crystal growth.
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
31. What is the protein efficiency ratio (PER) of casein?
Aspartic Acid and Phenylalanine
The speed of a molecule is proportional to the surrounding voltage gradient.
Lipid oxidation
2.5
32. Is a disaccharide
Sucrose
Orange Juice
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).
33. Name two enzymes that are involved in softening fruits.
Pectin Esterase - Polygalacturonase - Pectin Layase
Browning of freshly cut surfaces of fruits and vegetables.
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
D: None of the above
34. What is the chemical nature of anthocyanins?
Glycosides of anthocyanidins
It explodes
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Troponins and Tropomyosin
35. Q What reaction does the enzyme 'reverse transcriptase' catalyze?
Cis
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Browning of freshly cut surfaces of fruits and vegetables.
RNA transcribed to DNA
36. Name two main gluten proteins.
Polyphenol Oxidase
Gliadins and Glutenins
Capsaicin
Browning of freshly cut surfaces of fruits and vegetables.
37. What are the limiting amino acids in corn - potato - and green peas?
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Emulsification
Sodium chloride reduces foam stability and sucrose improves foam stability.
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
38. 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
A concentrate of microfibrillar proteins of fish muscle.
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Water
39. If the absorption of a sample is being determined spectrophotometrically at 420 nm what color is the sample?
Onions ( or leeks)
Pectin methylesterase & polygalacturonase
Yellow
NaCl (it dissociated to a 2M solution)
40. Name 4 advantages of using enzymes in food processing.
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
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Plasmids
D: None of the above
41. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
Fatty Acid and Alcohol
Capsaicin
Four
They act as catalysts - speeding the polymerization of acrylamide.
42. What are 3 mesomorphic structures associated with lipids in the liquid state?
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.
45% - 52% - 90%
Glycosides of anthocyanidins
43. What happens to chlorophyll on heating?
Pheophytin forms
Bright green
ERH=100 x Aw
Phenylketonuria
44. What is an isomer that is cheaper than Vitamin C?
Thermus Aqauticus
Erythorbic Acid
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Yellow
45. How many polypeptide chains make up an antibody?
Nucleation or crystal formation and crystal growth.
.05
RNA transcribed to DNA
Four
46. What does MSG stand for?
20 carbons and 4 double bonds
Monosodium Glutamate
1 - 3 - 7-trimethylxanthine
Arachidonic Acid
47. Name the strongest biochemical bond and the weakest biochemical bond.
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Fatty Acid and Alcohol
Covalent (strongest) and Hydrophobic (Weakest)
A concentrate of microfibrillar proteins of fish muscle.
48. Name three nonpolar polar - and charged amino acids.
DNA transferred by cell to cell contact (bacterial sex).
Degradation of protein and production of acid from sugar at the same time.
Whole Milk
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
49. Which of these foods is not appropriate to this list? A) Salami B) Yogurt C) Orange Juice D) Beer
DNA transferred by cell to cell contact (bacterial sex).
Orange Juice
Pectin methylesterase & polygalacturonase
Thamautin
50. How does ERH relate to water activity?
ERH=100 x Aw
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Covalent (strongest) and Hydrophobic (Weakest)
Aspartic Acid and Phenylalanine