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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. What is the enzyme responsible for browning in apples and lettuce?
Polyphenol Oxidase
Emulsoids
Initiation - Propagation - and Termination
Oil in Water
2. Define molarity molality - and normality.
Milk
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
45% - 52% - 90%
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
3. What is the name of the structural carbohydrate found in lobsters crab - shellfish - and insects?
Capsaicin
Gossypol (it is removed during the oil refining process)
20 carbons and 4 double bonds
Chitin
4. What are the primary secondary - tertiary - and quaternary structures?
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.
Prolamines
Initiation - Propagation - Termination
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
5. If oxygen attacks an unsaturated fatty acids at the double bond What is the resultant product?
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Polyphenoloxidase
Two aldehydes
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
6. Food additive that could be used to prevent cocoa particles from settling in chocolate milk
Carrageenan
Polyphenoloxidase
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
NaCl (it dissociated to a 2M solution)
7. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
20 carbons and 4 double bonds
Parabens
Onions ( or leeks)
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
8. What are the limiting amino acids in corn - potato - and green peas?
Lipase
Pectin methylesterase & polygalacturonase
Onions ( or leeks)
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
9. What is the chemical nature of anthocyanins?
Glycosides of anthocyanidins
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
10. What does Acid Degree Value measure and how is it measured?
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Capsaicin
D: None of the above
11. What is the name given to a mixture of equal parts of Darel Lisomers?
Racemic Mixture
Fatty Acid (Ester linked) to Fatty Alcohol
Covalent (strongest) and Hydrophobic (Weakest)
pH below positive charge; pH at no charge; pH above negative charge
12. What two types of compounds are joined with an ester bond to make a wax?
2.5
pH 3-5
Polyphenoloxidase
Fatty Acid and Alcohol
13. What is Ohm's Law and What is Power Equation?
V=IR and P=VI or I x I x are
RNA transcribed to DNA
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Lycopenes
14. What degradative enzyme causes browning in apples - pears - bananas - and peaches?
Chlocophyllide does not have a phytoltail
Troponins and Tropomyosin
2.5
Polyphenoloxidase
15. When heated ammonium bicarbonate decomposes to form what end products?
Bright green
Fatty Acid (Ester linked) to Fatty Alcohol
Ammonia - Water - Carbon Dioxide
Linoleic Acid
16. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
.05
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Emulsoids
17. What is Ohm's Law and What is Power Equation?
Water
V=IR and P=VI or I x I x are
Fatty Acid and Alcohol
Thermus Aqauticus
18. What compounds oxidize to form brown color in fruits and vegetables?
Whole Milk
Acsulfame-K - Saccharin - Cyclamate - Aspartame
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Polyphenols
19. What happens to chlorophyll on heating?
Pheophytin forms
Sucrose
Capsaicin
14
20. Name three nonpolar polar - and charged amino acids.
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Arachidonic Acid
21. What is the winterization process for an oil?
Olive Green
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Prolamines
22. Waxes are composed of what two basic chemical entities?
Orange Juice
Whole Milk
Thickener in foods
Fatty Acid (Ester linked) to Fatty Alcohol
23. How many carbon atoms and how many double bonds are there in arachidonic acid?
Anomeric
Covalent (strongest) and Hydrophobic (Weakest)
Erythorbic Acid
20 carbons and 4 double bonds
24. What charge will a protein have when the pH of its solution is below at - and above its pKa?
Plasmids
Pectin methyl esterase or galacturonase
pH below positive charge; pH at no charge; pH above negative charge
Fructose
25. What is acid proteolysis?
Fatty Acid (Ester linked) to Fatty Alcohol
Degradation of protein and production of acid from sugar at the same time.
They act as catalysts - speeding the polymerization of acrylamide.
Parabens
26. What charge will a protein have when the pH of its solution is below at - and above its pKa?
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Phenophylin
pH below positive charge; pH at no charge; pH above negative charge
Sodium bicarbonate generates CO2
27. What are two common reducing agents that break disulfide bonds in proteins?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
D: None of the above
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
20 carbons and 4 double bonds
28. Name two non-enzymatic browning reactions.
Erythorbic Acid
Emulsification
Carmelization and Maillard
Oil in Water
29. What metabolic disorder prevents conversion of phenulalanine to tyrosine by normal metabolic pathways?
Anthocyanins
An enzyme that converts hydrogen peroxide to water plus oxygen.
Phenophylin
Phenylketonuria
30. Peptide bond formation results in the formation of what secondary compound?
Water
Thickener in foods
Anomeric
Sodium bicarbonate generates CO2
31. How is pH defined?
Negative log of the hydrogen concentration (mol/l).
Racemic Mixture
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Nucleation or crystal formation and crystal growth.
32. An emulsifier with a high hydrophilic-lipophilic balance (HLB) value would promote which type of emulsion: oil in water or water in oil?
Emulsoids
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Oil in Water
ERH=100 x Aw
33. What is the chemical nature of anthocyanins?
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.
Phenophylin
Glycosides of anthocyanidins
Anthocyanins
34. What is the enzyme that softens tomatoes?
Bright green
Pectin Esterase
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Yes
35. Q What reaction does the enzyme 'reverse transcriptase' catalyze?
RNA transcribed to DNA
Erythorbic Acid
Water
Lysine - Arginine - and Histidine
36. Alar is the trade name for what chemical compound?
Polyphenoloxidase
Erythorbic Acid
Daminozide
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
37. What are proteins which are soluble in 50-80% ethanol known as?
Prolamines
Emulsoids
Lysine - Arginine - and Histidine
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.
38. Name three nonpolar polar - and charged amino acids.
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
An enzyme that converts hydrogen peroxide to water plus oxygen.
Parabens
Capsaicin
39. What toxic pigment is found in cottonseed endosperm?
Tryptophan
Fatty Acid (Ester linked) to Fatty Alcohol
They act as catalysts - speeding the polymerization of acrylamide.
Gossypol (it is removed during the oil refining process)
40. Give one word for a carbon atom involved in hemiacetal or acetal formation.
Phenylketonuria
Osmosis
Lamellar; Hexagonal I - II; Cubic
Anomeric
41. Name three factors useful in controlling enzyme activity.
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Olive Green
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
42. Name 3 factors influencing the rate of lipid oxidation in foods.
Lipase
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Olive Green
Blue pigment in flowers
43. What does the 'c' stand for in the equation E=mc2?
D: None of the above
Speed of Light
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Capsaicin
44. If the absorption of a sample is being determined spectrophotometrically at 420 nm what color is the sample?
Lipid oxidation
Yellow
Sucrose
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
45. What does the iodine value measure and how is it measured?
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Sucrose
Lipid oxidation
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
46. What name is given to the small circular DNA molecules that carry genetic information independently of the main bacterial chromosome?
Troponins and Tropomyosin
Tryptophan
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Plasmids
47. In genetics What is conjugation?
DNA transferred by cell to cell contact (bacterial sex).
Polyphenoloxidase
Yes
pH below positive charge; pH at no charge; pH above negative charge
48. 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.
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Fructose
Capsaicin
49. What happens to chlorophyll on heating?
Sodium bicarbonate generates CO2
Linoleic Acid
Pheophytin forms
Fructose
50. What are the fructose contents in commercial HFCS products.
Plasmids
45% - 52% - 90%
Fatty Acid (Ester linked) to Fatty Alcohol
2.5