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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 amino acid has the greatest molecular weight: tryptophan or tyrosine?
Negative log of the hydrogen concentration (mol/l).
Water
Erythorbic Acid
Tryptophan
2. What is the name of the structural carbohydrate found in lobsters crab - shellfish - and insects?
Browning of freshly cut surfaces of fruits and vegetables.
Yellow
pH below positive charge; pH at no charge; pH above negative charge
Chitin
3. The undesirable clarification of orange juice or tomato juice (precipitation of pulp) is caused by what enzymes?
Fatty Acid (Ester linked) to Fatty Alcohol
Ammonia - Water - Carbon Dioxide
Pectin methyl esterase or galacturonase
1 - 3 - 7-trimethylxanthine
4. A chlorophyll molecule reacting with hydrogen exhibits what shade of green?
Tryptophan
Speed of Light
Olive Green
Emulsification
5. What is the Peroxide Value a measure of?
Olive Green
Thamautin
Fat Oxidation
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.
6. What are the four basic flavors perceived by the tongue?
Glycosides of anthocyanidins
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Sweet - Salty - Sour - and Bitter
Fatty Acid (Ester linked) to Fatty Alcohol
7. 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
A concentrate of microfibrillar proteins of fish muscle.
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Nucleation or crystal formation and crystal growth.
8. What compounds oxidize to form brown color in fruits and vegetables?
Polyphenols
Sodium chloride reduces foam stability and sucrose improves foam stability.
Acetoin
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
9. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
Pectin methyl esterase or galacturonase
Oil in Water
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Bitter
10. What are the primary secondary - tertiary - and quaternary structures?
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
Initiation - Propagation - and Termination
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.
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
11. Does kosmotrophil ion discourage water structure?
Erythorbic Acid
No
Phenylketonuria
Prolamines
12. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
Bitter
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Sucrose
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
13. What does Acid Degree Value measure and how is it measured?
Polyphenol Oxidase
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
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.
14. Name three nonpolar polar - and charged amino acids.
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Degradation of protein and production of acid from sugar at the same time.
Four
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
15. What is the structural difference between chlorophyll and chlocophyllide?
2.5
Emulsoids
Chlocophyllide does not have a phytoltail
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.
16. What does the acronym NPN stand for?
Non-protein nitrogen
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.
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Prolamines
17. Name one way foam stability can be assessed.
Lipid oxidation
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
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.
The speed of a molecule is proportional to the surrounding voltage gradient.
18. Name 3 physical agents capable of denaturing proteins.
Pectin methyl esterase or galacturonase
Yes
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
19. Name 4 advantages of using enzymes in food processing.
Pectin Esterase
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
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Bitter
20. Q What reaction does the enzyme 'reverse transcriptase' catalyze?
Sucrose
Thickener in foods
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.
RNA transcribed to DNA
21. 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?
A concentrate of microfibrillar proteins of fish muscle.
Sodium chloride reduces foam stability and sucrose improves foam stability.
Onions ( or leeks)
It explodes
22. At low water activity What is the main deteriorative concern?
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Lipid oxidation
Sucrose
23. What pigment was first designated as anthocyanins?
Carrageenan
Oil in Water
Blue pigment in flowers
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
24. What is the chemical nature of anthocyanins?
Milk
D: None of the above
Glycosides of anthocyanidins
Anthocyanins
25. 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.
Browning of freshly cut surfaces of fruits and vegetables.
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Prolamines
26. What is the main class of color compounds found in raspberries?
A concentrate of microfibrillar proteins of fish muscle.
Gossypol (it is removed during the oil refining process)
Anthocyanins
Cis
27. In genetics What is conjugation?
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
DNA transferred by cell to cell contact (bacterial sex).
Bright green
Pectins
28. What name is given to the small circular DNA molecules that carry genetic information independently of the main bacterial chromosome?
Polyphenol Oxidase
.05
Plasmids
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
29. How many polypeptide chains make up an antibody?
No
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Four
30. What degradative enzyme causes browning in apples - pears - bananas - and peaches?
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Monosodium Glutamate
Polyphenoloxidase
.05
31. What ketohexose is most significant to food chemists?
It explodes
Fructose
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
Initiation - Propagation - and Termination
32. What charge will a protein have when the pH of its solution is below at - and above its pKa?
Pectin methylesterase & polygalacturonase
pH below positive charge; pH at no charge; pH above negative charge
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Carrageenan
33. A chlorophyll molecule reacting with magnesium exhibits what shade of green?
Fatty Acid (Ester linked) to Fatty Alcohol
Bright green
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Pectin methylesterase & polygalacturonase
34. 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
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Yes
Phenylketonuria
35. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
Bitter
Polyphenol Oxidase
Polyphenoloxidase
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
36. How many polypeptide chains make up an antibody?
Degradation of protein and production of acid from sugar at the same time.
45% - 52% - 90%
Four
Carrageenan
37. 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?
DNA transferred by cell to cell contact (bacterial sex).
Chlocophyllide does not have a phytoltail
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Erythorbic Acid
38. Name the three positively charged amino acids.
Browning of freshly cut surfaces of fruits and vegetables.
No
Lysine - Arginine - and Histidine
Aspartic Acid and Phenylalanine
39. Food additive that could be used to prevent cocoa particles from settling in chocolate milk
Cis
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Osmosis
Carrageenan
40. 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)
Two aldehydes
Daminozide
Covalent (strongest) and Hydrophobic (Weakest)
41. What are the three stages of oxidative rancidity?
Browning of freshly cut surfaces of fruits and vegetables.
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
Plasmids
Initiation - Propagation - and Termination
42. Name three non-nutritive sweeteners approved for use in USA?
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
They act as catalysts - speeding the polymerization of acrylamide.
Covalent (strongest) and Hydrophobic (Weakest)
43. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
Onions ( or leeks)
Parabens
Non-protein nitrogen
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.
44. Name three non-nutritive sweeteners approved for use in USA?
Lysine - Arginine - and Histidine
Daminozide
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Gossypol (it is removed during the oil refining process)
45. A chlorophyll molecule reacting with magnesium exhibits what shade of green?
Fat Oxidation
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Polyphenoloxidase
Bright green
46. Name 2 heat stable enzymes in food that are important to the quality of aseptic products.
Tryptophan
Phenylketonuria
Pectin Esterase
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
47. What is the structural difference between chlorophyll and chlocophyllide?
Chlocophyllide does not have a phytoltail
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Thermus Aqauticus
48. An emulsifier with a high hydrophilic-lipophilic balance (HLB) value would promote which type of emulsion: oil in water or water in oil?
Oil in Water
Fructose
Water
.05
49. What are colloids that are stabilized by a layer of solvation called?
Emulsoids
Whole Milk
It explodes
Water
50. What is acid proteolysis?
Lamellar; Hexagonal I - II; Cubic
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Degradation of protein and production of acid from sugar at the same time.
Polyphenols