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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. Name the most common functional property of phospholipids in food systems.
Emulsification
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
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.
Fructose
2. What are colloids that are stabilized by a layer of solvation called?
Monosodium Glutamate
Emulsoids
Thamautin
14
3. Name a commonly used household chemical leavening agent and the gas it generates.
Chitin
Thamautin
Daminozide
Sodium bicarbonate generates CO2
4. Will lipid oxidation be higher at a water activity of .05 or .5?
.05
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Phenophylin
Tryptophan
5. What are the only phenols approved for use in the microbiological preservation of foods?
Initiation - Propagation - and Termination
Parabens
Pectin Esterase - Polygalacturonase - Pectin Layase
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 is the chemical nature of anthocyanins?
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Prolamines
Glycosides of anthocyanidins
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.
7. What are proteins which are soluble in 50-80% ethanol known as?
Anomeric
Thamautin
Chitin
Prolamines
8. What happens to chlorophyll on heating?
Yes
Pheophytin forms
2.5
Onions ( or leeks)
9. What is the chemical nature of anthocyanins?
Glycosides of anthocyanidins
Carrageenan
Polyphenoloxidase
Lipase
10. 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?
Two aldehydes
Lamellar; Hexagonal I - II; Cubic
Fructose
It explodes
11. What enzyme is most responsible for browning bananas?
Lysine - Arginine - and Histidine
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Polyphenol Oxidase
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
12. What name is given to the small circular DNA molecules that carry genetic information independently of the main bacterial chromosome?
Monosodium Glutamate
Phenylketonuria
Plasmids
Lipase
13. What are proteins which are soluble in 50-80% ethanol known as?
Prolamines
V=IR and P=VI or I x I x are
Lycopenes
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
14. In the enzyme Taq Polymerase What does Taq stand for?
Ascorbic Acid and Citric Acid
Thermus Aqauticus
Blue pigment in flowers
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
15. What are 3 mesomorphic structures associated with lipids in the liquid state?
Olive Green
Linoleic Acid
Plasmids
Lamellar; Hexagonal I - II; Cubic
16. How many carbon atoms and how many double bonds are there in arachidonic acid?
Plasmids
Ascorbic Acid and Citric Acid
20 carbons and 4 double bonds
.05 M HCL
17. The undesirable clarification of orange juice or tomato juice (precipitation of pulp) is caused by what enzymes?
Pectin methyl esterase or galacturonase
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
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
Whole Milk
18. What charge will a protein have when the pH of its solution is below at - and above its pKa?
pH below positive charge; pH at no charge; pH above negative charge
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
Polyphenols
Nucleation or crystal formation and crystal growth.
19. Define molarity molality - and normality.
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
14
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Orange Juice
20. Which will be coldest at its freezing point: 1M dispersion of amylose 1M solution of NaCl - distilled water - or 1M solution of sucrose?
Pheophytin forms
NaCl (it dissociated to a 2M solution)
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
.05 M HCL
21. Which of these foods is not appropriate to this list? A) Salami B) Yogurt C) Orange Juice D) Beer
Orange Juice
Initiation - Propagation - and Termination
Water
Monosodium Glutamate
22. How is pH defined?
Erythorbic Acid
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Negative log of the hydrogen concentration (mol/l).
Emulsification
23. Name 3 physical agents capable of denaturing proteins.
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Fatty Acid and Alcohol
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Chitin
24. How does HPLC differ from FPLC?
Daminozide
Carrageenan
Pectin methyl esterase or galacturonase
HPLC has higher pressure than FPLC
25. What is the main class of color compounds found in raspberries?
Anthocyanins
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Polyphenol Oxidase
Covalent (strongest) and Hydrophobic (Weakest)
26. A chlorophyll molecule reacting with magnesium exhibits what shade of green?
Monosodium Glutamate
A concentrate of microfibrillar proteins of fish muscle.
Bright green
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
27. Name two enzymes that are involved in softening fruits.
Pectin Esterase - Polygalacturonase - Pectin Layase
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
Capsaicin
28. What is the acid present in fish oil?
Osmosis
Negative log of the hydrogen concentration (mol/l).
Arachidonic Acid
Yellow
29. To which of the following four basic tastes are humans most sensitive? A) Bitter B) Sweet C) Sour D) Salty
Bitter
Chitin
Carrageenan
pH below positive charge; pH at no charge; pH above negative charge
30. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
Pectins
Polyphenol Oxidase
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
31. What are the limiting amino acids in corn - potato - and green peas?
HPLC has higher pressure than FPLC
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
Glycosides of anthocyanidins
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
32. Peptide bond formation results in the formation of what secondary compound?
NaCl (it dissociated to a 2M solution)
Polyphenoloxidase
Water
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.
33. 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?
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.
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Bitter
Sweet - Salty - Sour - and Bitter
34. What is the fundamental driving of electrophoresis?
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
The speed of a molecule is proportional to the surrounding voltage gradient.
Lipid oxidation
Whole Milk
35. What metabolic end product does the Voges-Proskauer test detect?
Acetoin
Lipid oxidation
NaCl (it dissociated to a 2M solution)
Prolamines
36. What is the name of the degradation compound of chlorophyll?
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Aspartic Acid and Phenylalanine
Phenophylin
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
37. Name 2 heat stable enzymes in food that are important to the quality of aseptic products.
Plasmids
Lycopenes
Carmelization and Maillard
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
38. Which of these foods is not appropriate to this list? A) Salami B) Yogurt C) Orange Juice D) Beer
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Daminozide
Orange Juice
Pectin Esterase
39. What is the geometric configuration of double bonds in most natural fatty acids?
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
D: None of the above
Cis
Nucleation or crystal formation and crystal growth.
40. What is the enzyme responsible for browning in apples and lettuce?
Acids - Alkalis - Metals - Organic Solvents - and Aqueous Solutions of Organic Solvents
The speed of a molecule is proportional to the surrounding voltage gradient.
Polyphenol Oxidase
Carrageenan
41. If oxygen attacks an unsaturated fatty acids at the double bond What is the resultant product?
Sweet - Salty - Sour - and Bitter
Two aldehydes
Non-protein nitrogen
Sodium bicarbonate generates CO2
42. At low water activity What is the main deteriorative concern?
Monosodium Glutamate
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Prolamines
Lipid oxidation
43. At what pH is benzoic acid most effective?
RNA transcribed to DNA
Fatty Acid and Alcohol
Acsulfame-K - Saccharin - Cyclamate - Aspartame
pH 3-5
44. Are sorbitol and mannitol sweet?
Water
Whole Milk
Yes
Racemic Mixture
45. 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
Browning of freshly cut surfaces of fruits and vegetables.
Troponins and Tropomyosin
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.
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
46. Name two non-enzymatic browning reactions.
Erythorbic Acid
Gossypol (it is removed during the oil refining process)
Carmelization and Maillard
NaCl (it dissociated to a 2M solution)
47. What is an isomer that is cheaper than Vitamin C?
Glycosides of anthocyanidins
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
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.
Erythorbic Acid
48. What is a polymorphism?
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Thermus Aqauticus
Four
pH 3-5
49. What is the protein efficiency ratio (PER) of casein?
Polyphenol Oxidase
Thermus Aqauticus
2.5
Daminozide
50. What metabolic end product does the Voges-Proskauer test detect?
Anthocyanins
Lipid oxidation
Acetoin
Arachidonic Acid