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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. How many carbon atoms are there in the fatty acid myristic acid?
14
20 carbons and 4 double bonds
20 carbons and 4 double bonds
Initiation - Propagation - Termination
2. What ketohexose is most significant to food chemists?
Osmosis
Fructose
Milk
pH 3-5
3. Name a naturally occurring protein sweetener.
Linoleic Acid
Thamautin
Bitter
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
4. A chlorophyll molecule reacting with hydrogen exhibits what shade of green?
Polyphenol Oxidase
Four
Olive Green
Emulsification
5. What is the winterization process for an oil?
Erythorbic Acid
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
ERH=100 x Aw
D: None of the above
6. Name 2 heat stable enzymes in food that are important to the quality of aseptic products.
Aspartic Acid and Phenylalanine
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Thermus Aqauticus
Pectins
7. If oxygen attacks an unsaturated fatty acids at the double bond What is the resultant product?
Pectin methylesterase & polygalacturonase
Polyphenol Oxidase
Capsaicin
Two aldehydes
8. S-(1-propenyl)-L-cysteine sulfoxide is the chemical precursor to the major flavor compounds In what foodstuff?
Glycosides of anthocyanidins
Onions ( or leeks)
Fatty Acid and Alcohol
Cis
9. What are the limiting amino acids in corn - potato - and green peas?
Erythorbic Acid
Primary butyric acid also caproic acid.
pH 3-5
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
10. What is the geometric configuration of double bonds in most natural fatty acids?
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Pheophytin forms
Ascorbic Acid and Citric Acid
Cis
11. Name three compounds capable of poisoning the catalyst during commercial hydrogenation.
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Pectin methyl esterase or galacturonase
Polyphenol Oxidase
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
12. What is the chemical nature of anthocyanins?
Emulsification
Glycosides of anthocyanidins
RNA transcribed to DNA
Ammonia - Water - Carbon Dioxide
13. Which two amino acids is the aspartame derived from?
Orange Juice
Non-protein nitrogen
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Aspartic Acid and Phenylalanine
14. Name a naturally occurring protein sweetener.
Thamautin
HPLC has higher pressure than FPLC
Acetoin
Lipase
15. Are sorbitol and mannitol sweet?
Yes
Phenylketonuria
Parabens
Gossypol (it is removed during the oil refining process)
16. 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?
Primary butyric acid also caproic acid.
Sodium bicarbonate generates CO2
.05 M HCL
Pectin methylesterase & polygalacturonase
17. What kinds of food emulsions are? (1) Butter (2) Mayonnaise(3) Milk
Carmelization and Maillard
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Four
Negative log of the hydrogen concentration (mol/l).
18. Name a commonly used household chemical leavening agent and the gas it generates.
Sweet - Salty - Sour - and Bitter
Degradation of protein and production of acid from sugar at the same time.
Sodium bicarbonate generates CO2
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. How many polypeptide chains make up an antibody?
Daminozide
Nucleation or crystal formation and crystal growth.
Four
Sodium chloride reduces foam stability and sucrose improves foam stability.
20. Name the three positively charged amino acids.
Water
Lysine - Arginine - and Histidine
14
Prolamines
21. What is the major color compound in tomatoes?
Thickener in foods
Chitin
Gliadins and Glutenins
Lycopenes
22. A) Is the major component of most foods.B) Controls shelf-life or storage capabilityC) Regulates chemical and microbiological reactionsD) All of the above
Phenylketonuria
Yes
Daminozide
Water
23. What is the movement of molecules through a semi permeable membrane from a region of low to high solute concentration called?
Osmosis
NaCl (it dissociated to a 2M solution)
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
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.
24. Which of these foods is not appropriate to this list? A) Salami B) Yogurt C) Orange Juice D) Beer
Daminozide
The speed of a molecule is proportional to the surrounding voltage gradient.
Orange Juice
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
25. What two types of compounds are joined with an ester bond to make a wax?
Fatty Acid and Alcohol
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Initiation - Propagation - and Termination
Blue pigment in flowers
26. What charge will a protein have when the pH of its solution is below at - and above its pKa?
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
pH below positive charge; pH at no charge; pH above negative charge
Yes
Polyphenols
27. Name two non-enzymatic browning reactions.
Sodium bicarbonate generates CO2
Carmelization and Maillard
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
28. What are two common reducing agents that break disulfide bonds in proteins?
Speed of Light
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
RNA transcribed to DNA
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
29. Alar is the trade name for what chemical compound?
Daminozide
Lycopenes
Pectin Esterase
Monosodium Glutamate
30. An emulsifier with a high hydrophilic-lipophilic balance (HLB) value would promote which type of emulsion: oil in water or water in oil?
Pheophytia does not have magnesium in porphyrin ring.
Degradation of protein and production of acid from sugar at the same time.
Chlocophyllide does not have a phytoltail
Oil in Water
31. A chlorophyll molecule reacting with magnesium exhibits what shade of green?
Pheophytia does not have magnesium in porphyrin ring.
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Bright green
32. Name 3 factors influencing the consistency of commercial fats.
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Two aldehydes
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the 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
33. Name the two components that comprise the relaxing factor in muscle fibers.
Troponins and Tropomyosin
Degradation of protein and production of acid from sugar at the same time.
NaCl (it dissociated to a 2M solution)
Fat Oxidation
34. In what food is butyric acid typically found?
Milk
Onions ( or leeks)
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
35. What is Ohm's Law and What is Power Equation?
Plasmids
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
V=IR and P=VI or I x I x are
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
36. What is the chemical nomenclature for caffeine?
1 - 3 - 7-trimethylxanthine
A concentrate of microfibrillar proteins of fish muscle.
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.
Fatty Acid and Alcohol
37. What does the iodine value measure and how is it measured?
Fatty Acid (Ester linked) to Fatty Alcohol
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
pH 3-5
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. If the absorption of a sample is being determined spectrophotometrically at 420 nm what color is the sample?
The speed of a molecule is proportional to the surrounding voltage gradient.
.05 M HCL
Yellow
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
39. Name the most common functional property of phospholipids in food systems.
Pectin Esterase - Polygalacturonase - Pectin Layase
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Emulsification
2.5
40. What are soluble polymers of anhydro-galacturonic acid and its esters called?
Fatty Acid and Alcohol
Glycosides of anthocyanidins
HPLC has higher pressure than FPLC
Pectins
41. When heated ammonium bicarbonate decomposes to form what end products?
Bitter
Aspartic Acid and Phenylalanine
Covalent (strongest) and Hydrophobic (Weakest)
Ammonia - Water - Carbon Dioxide
42. How does ERH relate to water activity?
Chlocophyllide does not have a phytoltail
Plasmids
ERH=100 x Aw
Pectin Esterase - Polygalacturonase - Pectin Layase
43. How is pH defined?
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
Negative log of the hydrogen concentration (mol/l).
Prolamines
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.
44. 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
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
Molarity is moles of substance per liter solution. Molality is moles of substance per kg solvent. Normality is equivalents of substance per liter solution.
Speed of Light
D: None of the above
45. What does MSG stand for?
Monosodium Glutamate
Pheophytin forms
Emulsification
Onions ( or leeks)
46. In what food is butyric acid typically found?
Onions ( or leeks)
Milk
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Yes
47. How many carbon atoms and how many double bonds are there in arachidonic acid?
Sucrose
Troponins and Tropomyosin
20 carbons and 4 double bonds
NaCl (it dissociated to a 2M solution)
48. Name a commonly used household chemical leavening agent and the gas it generates.
2.5
Water
Sodium bicarbonate generates CO2
Onions ( or leeks)
49. Alar is the trade name for what chemical compound?
Daminozide
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Bitter
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
50. When heated ammonium bicarbonate decomposes to form what end products?
Ascorbic Acid and Citric Acid
Erythorbic Acid
Ammonia - Water - Carbon Dioxide
Speed of Light