SUBJECTS
|
BROWSE
|
CAREER CENTER
|
POPULAR
|
JOIN
|
LOGIN
Business Skills
|
Soft Skills
|
Basic Literacy
|
Certifications
About
|
Help
|
Privacy
|
Terms
|
Email
Search
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 name of the structural carbohydrate found in lobsters crab - shellfish - and insects?
Yes
Chitin
Water
14
2. What are the three main steps in the autooxidation of lipids?
Four
Initiation - Propagation - Termination
Bitter
Polyphenol Oxidase
3. What enzyme is most responsible for browning bananas?
The speed of a molecule is proportional to the surrounding voltage gradient.
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Cis
Polyphenol Oxidase
4. How does ERH relate to water activity?
ERH=100 x Aw
Sucrose
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Aspartic Acid and Phenylalanine
5. Name the two components that comprise the relaxing factor in muscle fibers.
NaCl (it dissociated to a 2M solution)
Troponins and Tropomyosin
Degradation of protein and production of acid from sugar at the same time.
Plasmids
6. What is the enzyme responsible for browning in apples and lettuce?
Polyphenol Oxidase
A concentrate of microfibrillar proteins of fish muscle.
Polyphenoloxidase
14
7. At what pH is benzoic acid most effective?
pH below positive charge; pH at no charge; pH above negative charge
Pectin Esterase - Polygalacturonase - Pectin Layase
Polyphenoloxidase
pH 3-5
8. What degradative enzyme causes browning in apples - pears - bananas - and peaches?
Polyphenoloxidase
Olive Green
Two aldehydes
Aspartic Acid and Phenylalanine
9. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
They act as catalysts - speeding the polymerization of acrylamide.
Erythorbic Acid
.05 M HCL
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.
10. Name three factors useful in controlling enzyme activity.
Sweet - Salty - Sour - and Bitter
NaCl (it dissociated to a 2M solution)
Bright green
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
11. Alar is the trade name for what chemical compound?
Emulsification
Lipase
Daminozide
Acetoin
12. What pigment was first designated as anthocyanins?
Phenophylin
Blue pigment in flowers
Nucleation or crystal formation and crystal growth.
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
13. In what food is butyric acid typically found?
Polyphenols
Yellow
The speed of a molecule is proportional to the surrounding voltage gradient.
Milk
14. What enzyme is most responsible for browning bananas?
2.5
Initiation - Propagation - and Termination
Thermus Aqauticus
Polyphenol Oxidase
15. What are two common reducing agents that break disulfide bonds in proteins?
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.
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Capsaicin
16. What is the movement of molecules through a semi permeable membrane from a region of low to high solute concentration called?
Covalent (strongest) and Hydrophobic (Weakest)
Water
Fat Oxidation
Osmosis
17. How is pH defined?
Blue pigment in flowers
Degradation of protein and production of acid from sugar at the same time.
Negative log of the hydrogen concentration (mol/l).
Covalent (strongest) and Hydrophobic (Weakest)
18. At low water activity What is the main deteriorative concern?
RNA transcribed to DNA
Lipid oxidation
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
19. 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.
ERH=100 x Aw
Non-protein nitrogen
RNA transcribed to DNA
20. What is the winterization process for an oil?
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Olive Green
Tryptophan
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
21. Name three compounds capable of poisoning the catalyst during commercial hydrogenation.
Glycosides of anthocyanidins
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Primary butyric acid also caproic acid.
22. How can a molecular weight of protein - DNA - and RNA be determined?
RNA transcribed to DNA
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Phenophylin
23. What is the fundamental driving of electrophoresis?
Yellow
The speed of a molecule is proportional to the surrounding voltage gradient.
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.
Gossypol (it is removed during the oil refining process)
24. What are the limiting amino acids in corn - potato - and green peas?
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Yes
D: None of the above
pH 3-5
25. What are the fructose contents in commercial HFCS products.
Milk
45% - 52% - 90%
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
26. The undesirable clarification of orange juice or tomato juice (precipitation of pulp) is caused by what enzymes?
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Pectin methyl esterase or galacturonase
Glycosides of anthocyanidins
20 carbons and 4 double bonds
27. If oxygen attacks an unsaturated fatty acids at the double bond What is the resultant product?
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Fatty Acid (Ester linked) to Fatty Alcohol
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Two aldehydes
28. 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
Ammonia - Water - Carbon Dioxide
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Browning of freshly cut surfaces of fruits and vegetables.
Orange Juice
29. Alar is the trade name for what chemical compound?
Pheophytin forms
NaCl (it dissociated to a 2M solution)
Daminozide
They act as catalysts - speeding the polymerization of acrylamide.
30. What are soluble polymers of anhydro-galacturonic acid and its esters called?
Racemic Mixture
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
.05 M HCL
Pectins
31. Which will be coldest at its freezing point: 1M dispersion of amylose 1M solution of NaCl - distilled water - or 1M solution of sucrose?
Pectin methylesterase & polygalacturonase
Nucleation or crystal formation and crystal growth.
NaCl (it dissociated to a 2M solution)
Polyphenol Oxidase
32. How does ERH relate to water activity?
ERH=100 x Aw
2.5
Pheophytia does not have magnesium in porphyrin ring.
Thamautin
33. What happens to chlorophyll on heating?
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Pheophytin forms
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Lamellar; Hexagonal I - II; Cubic
34. What is acid proteolysis?
NaCl (it dissociated to a 2M solution)
Four
Cis
Degradation of protein and production of acid from sugar at the same time.
35. Are sorbitol and mannitol sweet?
Gossypol (it is removed during the oil refining process)
Yes
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Initiation - Propagation - Termination
36. 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?
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Thermus Aqauticus
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.
.05 M HCL
37. What two common compounds are used together as an antioxidative system?
Tryptophan
Ascorbic Acid and Citric Acid
Fatty Acid and Alcohol
.05
38. Waxes are composed of what two basic chemical entities?
Olive Green
Fatty Acid (Ester linked) to Fatty Alcohol
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Water
39. Name 5 proteins with good foaming properties.
Lamellar; Hexagonal I - II; Cubic
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
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.
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
40. How does HPLC differ from FPLC?
RNA transcribed to DNA
D: None of the above
HPLC has higher pressure than FPLC
Ascorbic Acid and Citric Acid
41. What is an isomer that is cheaper than Vitamin C?
Erythorbic Acid
Initiation - Propagation - Termination
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
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
42. What is the name given to a mixture of equal parts of Darel Lisomers?
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Erythorbic Acid
Racemic Mixture
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
43. Name three effects of protein denaturation.
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Bitter
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Sucrose
44. What two enzymes degrade pectic substances?
Pectin methylesterase & polygalacturonase
Lipase
pH below positive charge; pH at no charge; pH above negative charge
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
45. Peptide bond formation results in the formation of what secondary compound?
Water
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
Tryptophan
2.5
46. Name three effects of protein denaturation.
Osmosis
20 carbons and 4 double bonds
HPLC has higher pressure than FPLC
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
47. What are the only phenols approved for use in the microbiological preservation of foods?
Negative log of the hydrogen concentration (mol/l).
Phenylketonuria
Parabens
Emulsoids
48. What metabolic end product does the Voges-Proskauer test detect?
Oil in Water
Acetoin
2.5
Osmosis
49. 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
Lipase
D: None of the above
pH 3-5
Polyphenols
50. Does kosmotrophil ion discourage water structure?
Pectins
Emulsification
No
pH below positive charge; pH at no charge; pH above negative charge