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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 pigment was first designated as anthocyanins?
Blue pigment in flowers
Lysine - Arginine - and Histidine
Initiation - Propagation - and Termination
Covalent (strongest) and Hydrophobic (Weakest)
2. Name a commonly used household chemical leavening agent and the gas it generates.
Erythorbic Acid
Sodium bicarbonate generates CO2
.05 M HCL
1 - 3 - 7-trimethylxanthine
3. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Two aldehydes
Carrageenan
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.
4. What degradative enzyme causes browning in apples - pears - bananas - and peaches?
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Pectin methyl esterase or galacturonase
Polyphenoloxidase
Water
5. Which amino acid has the greatest molecular weight: tryptophan or tyrosine?
Parabens
20 carbons and 4 double bonds
Bitter
Tryptophan
6. Alar is the trade name for what chemical compound?
An enzyme that converts hydrogen peroxide to water plus oxygen.
Daminozide
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Polyphenol Oxidase
7. A chlorophyll molecule reacting with magnesium exhibits what shade of green?
Polyphenoloxidase
Bright green
Lipid oxidation
Monosodium Glutamate
8. 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
20 carbons and 4 double bonds
.05
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
D: None of the above
9. In genetics What is conjugation?
Polyphenol Oxidase
DNA transferred by cell to cell contact (bacterial sex).
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.
Carmelization and Maillard
10. How do sodium chloride and sucrose affect foam stability?
Four
Sodium chloride reduces foam stability and sucrose improves foam stability.
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
An enzyme that converts hydrogen peroxide to water plus oxygen.
11. What is Ohm's Law and What is Power Equation?
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Anomeric
V=IR and P=VI or I x I x are
Parabens
12. Name 5 proteins with good foaming properties.
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.
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
No
Polyphenols
13. Name two enzymes that are involved in softening fruits.
1 - 3 - 7-trimethylxanthine
Pectin Esterase
Carrageenan
Pectin Esterase - Polygalacturonase - Pectin Layase
14. What are two common reducing agents that break disulfide bonds in proteins?
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.
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
They act as catalysts - speeding the polymerization of acrylamide.
Water
15. What is a polymorphism?
Yes
Polyphenol Oxidase
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Four
16. Name one way foam stability can be assessed.
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.
Monosodium Glutamate
Fructose
It explodes
17. Name 3 reasons it is advantageous to obtain enzymes from microorganisms.
18. Name two main gluten proteins.
Prolamines
pH 3-5
45% - 52% - 90%
Gliadins and Glutenins
19. Which of these foods is not appropriate to this list? A) Salami B) Yogurt C) Orange Juice D) Beer
Bitter
Chlocophyllide does not have a phytoltail
Fat Oxidation
Orange Juice
20. What are 3 mesomorphic structures associated with lipids in the liquid state?
Negative log of the hydrogen concentration (mol/l).
Polyphenoloxidase
Ascorbic Acid and Citric Acid
Lamellar; Hexagonal I - II; Cubic
21. Name two reasons why fats are hydrogenated.
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
V=IR and P=VI or I x I x are
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
Fructose
22. Is a disaccharide
Two aldehydes
Sucrose
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Bitter
23. What happens to a bottle of wine if before you bottle it you forget to put the stuff in it that prevents it from fermenting?
It explodes
Tryptophan
Polyphenol Oxidase
Degradation of protein and production of acid from sugar at the same time.
24. What degradative enzyme causes browning in apples - pears - bananas - and peaches?
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
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Polyphenoloxidase
25. What does HLB stand for and What does a high and low HLB value indicate?
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.
Yellow
Orange Juice
26. Peptide bond formation results in the formation of what secondary compound?
Pectins
A concentrate of microfibrillar proteins of fish muscle.
Water
Browning of freshly cut surfaces of fruits and vegetables.
27. Name 3 chemical agents capable of denaturing proteins.
Initiation - Propagation - Termination
Polyphenoloxidase
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Speed of Light
28. What is the name of the structural carbohydrate found in lobsters crab - shellfish - and insects?
Chitin
Acetoin
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
29. Name three compounds capable of poisoning the catalyst during commercial hydrogenation.
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Prolamines
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
30. In what food is butyric acid typically found?
Emulsoids
Milk
Four
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
31. What metabolic end product does the Voges-Proskauer test detect?
Aspartic Acid and Phenylalanine
Racemic Mixture
Acetoin
Polyphenol Oxidase
32. What are the three main steps in the autooxidation of lipids?
Polyphenols
Tryptophan
Initiation - Propagation - Termination
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
33. What are two common reducing agents that break disulfide bonds in proteins?
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Sodium bicarbonate generates CO2
Ammonia - Water - Carbon Dioxide
Carmelization and Maillard
34. 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?
Gliadins and Glutenins
.05 M HCL
Parabens
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
35. Does kosmotrophil ion discourage water structure?
No
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
Primary butyric acid also caproic acid.
20 carbons and 4 double bonds
36. What enzyme causes hyrolytic rancidity in milk?
Prolamines
Tryptophan
Parabens
Lipase
37. Name 5 chelating agents used in the food industry.
Sweet - Salty - Sour - and Bitter
Acsulfame-K - Saccharin - Cyclamate - Aspartame
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Oil in Water
38. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
Bitter
pH 3-5
A concentrate of microfibrillar proteins of fish muscle.
Emulsoids
39. Name the three positively charged amino acids.
Whole Milk
Blue pigment in flowers
Polyphenols
Lysine - Arginine - and Histidine
40. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
Emulsification
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
They act as catalysts - speeding the polymerization of acrylamide.
Degradation of protein and production of acid from sugar at the same time.
41. Which of these foods is not appropriate to this list? A) Salami B) Yogurt C) Orange Juice D) Beer
Orange Juice
Fructose
Thermus Aqauticus
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
42. Which two amino acids is the aspartame derived from?
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.
Negative log of the hydrogen concentration (mol/l).
Gliadins and Glutenins
Aspartic Acid and Phenylalanine
43. What does MSG stand for?
Four
Prolamines
Plasmids
Monosodium Glutamate
44. How can a molecular weight of protein - DNA - and RNA be determined?
14
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
45. What is Carboxy-methyl cellulose often used for?
Two aldehydes
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.
Thickener in foods
Cis
46. Q What reaction does the enzyme 'reverse transcriptase' catalyze?
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Polyphenols
Two aldehydes
RNA transcribed to DNA
47. Name three nonpolar polar - and charged amino acids.
Lipid oxidation
Capsaicin
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)
48. What compounds oxidize to form brown color in fruits and vegetables?
Sweet - Salty - Sour - and Bitter
Tryptophan
Whole Milk
Polyphenols
49. What pigment was first designated as anthocyanins?
1 - 3 - 7-trimethylxanthine
Sweet - Salty - Sour - and Bitter
Blue pigment in flowers
Lysine - Arginine - and Histidine
50. What is the major color compound in tomatoes?
Browning of freshly cut surfaces of fruits and vegetables.
No
Lycopenes
Thamautin