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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 ketohexose is most significant to food chemists?
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Four
Carrageenan
Fructose
2. How many carbon atoms are there in the fatty acid myristic acid?
pH below positive charge; pH at no charge; pH above negative charge
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Lamellar; Hexagonal I - II; Cubic
14
3. Alar is the trade name for what chemical compound?
Orange Juice
It explodes
Osmosis
Daminozide
4. What is Ohm's Law and What is Power Equation?
Blue pigment in flowers
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
V=IR and P=VI or I x I x are
5. If the absorption of a sample is being determined spectrophotometrically at 420 nm what color is the sample?
Arachidonic Acid
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.
Yellow
Blue pigment in flowers
6. Which two amino acids is the aspartame derived from?
Aspartic Acid and Phenylalanine
DNA transferred by cell to cell contact (bacterial sex).
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Lipid oxidation
7. Which amino acid has the greatest molecular weight: tryptophan or tyrosine?
Lycopenes
Prolamines
Tryptophan
Lipase
8. What ketohexose is most significant to food chemists?
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Fructose
Initiation - Propagation - Termination
Anthocyanins
9. What chemical compound is responsible for the 'hot' principle of jalepeno peppers?
Capsaicin
Nucleation or crystal formation and crystal growth.
Daminozide
Sweet - Salty - Sour - and Bitter
10. What is the chemical nature of anthocyanins?
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.
Glycosides of anthocyanidins
Lipase
Lysine - Arginine - and Histidine
11. A chlorophyll molecule reacting with magnesium exhibits what shade of green?
Negative log of the hydrogen concentration (mol/l).
Lysine - Arginine - and Histidine
Bright green
Parabens
12. What two enzymes degrade pectic substances?
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Polyphenol Oxidase
100 Degrees Celsius (it is not a true solution-there is no boiling point of elevation)
Pectin methylesterase & polygalacturonase
13. What are the three stages of oxidative rancidity?
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.
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Olive Green
Initiation - Propagation - and Termination
14. 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
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
Fat Oxidation
Onions ( or leeks)
Browning of freshly cut surfaces of fruits and vegetables.
15. What does the iodine value measure and how is it measured?
Speed of Light
Acetoin
Two aldehydes
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
16. What are the three main steps in the autooxidation of lipids?
Chitin
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Initiation - Propagation - Termination
17. What are colloids that are stabilized by a layer of solvation called?
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Emulsoids
Non-protein nitrogen
Polyphenol Oxidase
18. Give one word for a carbon atom involved in hemiacetal or acetal formation.
Sweet - Salty - Sour - and Bitter
Browning of freshly cut surfaces of fruits and vegetables.
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
Anomeric
19. Alar is the trade name for what chemical compound?
.05 M HCL
Daminozide
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
20. What two common compounds are used together as an antioxidative system?
Fructose
Ascorbic Acid and Citric Acid
Thickener in foods
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
21. How many carbon atoms and how many double bonds are there in arachidonic acid?
Fat Oxidation
20 carbons and 4 double bonds
Lycopenes
.05
22. 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
Erythorbic Acid
Phenylketonuria
Monosodium Glutamate
23. 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
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
D: None of the above
Anthocyanins
Non-protein nitrogen
24. In the enzyme Taq Polymerase What does Taq stand for?
Covalent (strongest) and Hydrophobic (Weakest)
Nonpolar: (Valine - Alanine - Leucine - Isoleucine - Proline)Polar: (Glycine - Serine - Cystein - Threonine - Tyrosine)Charged: (Lysine - Arginine - Histidine - Aspartic Acid - Glutamic Acid)
Thermus Aqauticus
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
25. What is the enzyme that softens tomatoes?
Pectin Esterase
Acsulfame-K - Saccharin - Cyclamate - Aspartame
Thickener in foods
.05
26. Name the strongest biochemical bond and the weakest biochemical bond.
Pectin Esterase - Polygalacturonase - Pectin Layase
Browning of freshly cut surfaces of fruits and vegetables.
Covalent (strongest) and Hydrophobic (Weakest)
Initiation - Propagation - and Termination
27. Name the strongest biochemical bond and the weakest biochemical bond.
Covalent (strongest) and Hydrophobic (Weakest)
pH 3-5
Gliadins and Glutenins
Thamautin
28. What is the chemical nomenclature for caffeine?
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Phenylketonuria
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
1 - 3 - 7-trimethylxanthine
29. Name 5 proteins with good foaming properties.
HPLC has higher pressure than FPLC
Acsulfame-K - Saccharin - Cyclamate - Aspartame
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.
It allows the conversion of liquid oils into semisolid or plastic fats and it improves the oxidative stability of the fat.
30. Name a naturally occurring protein sweetener.
Thamautin
They act as catalysts - speeding the polymerization of acrylamide.
1 - 3 - 7-trimethylxanthine
Amount of free fatty acids present; mg KOH needed to neutralize the free fatty acids in 1 g of fat.
31. Will lipid oxidation be higher at a water activity of .05 or .5?
Yes
Gliadins and Glutenins
Orange Juice
.05
32. What metabolic disorder prevents conversion of phenulalanine to tyrosine by normal metabolic pathways?
An enzyme that converts hydrogen peroxide to water plus oxygen.
.05
Phenylketonuria
Non-protein nitrogen
33. 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?
Tryptophan
Lipase
Glycosides of anthocyanidins
.05 M HCL
34. Name two enzymes that are involved in softening fruits.
20 carbons and 4 double bonds
pH 3-5
Pectin Esterase - Polygalacturonase - Pectin Layase
Four
35. What are 3 mesomorphic structures associated with lipids in the liquid state?
Lamellar; Hexagonal I - II; Cubic
Pheophytin forms
14
Plasmids
36. What two types of compounds are joined with an ester bond to make a wax?
Fatty Acid and Alcohol
Nucleation or crystal formation and crystal growth.
Troponins and Tropomyosin
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
37. In genetics What is conjugation?
They act as catalysts - speeding the polymerization of acrylamide.
Carrageenan
DNA transferred by cell to cell contact (bacterial sex).
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.
38. What is the movement of molecules through a semi permeable membrane from a region of low to high solute concentration called?
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Osmosis
Olive Green
Acsulfame-K - Saccharin - Cyclamate - Aspartame
39. How does ERH relate to water activity?
Fat Oxidation
pH 3-5
Fatty acid composition - free fatty acids versus the corresponding glycerols - oxygen concentration - temperature - surface area - moisture - pro-oxidants - antioxidants
ERH=100 x Aw
40. What enzyme is most responsible for browning bananas?
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Polyphenol Oxidase
Bright green
41. Are sorbitol and mannitol sweet?
1 - 3 - 7-trimethylxanthine
Blue pigment in flowers
Yes
Ammonia - Water - Carbon Dioxide
42. What compounds oxidize to form brown color in fruits and vegetables?
Speed of Light
Polyphenols
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.
Emulsoids
43. Name 5 chelating agents used in the food industry.
Fat Oxidation
Pectin Esterase - Polygalacturonase - Pectin Layase
EDTA - citric acid - malic acid - tartaric acid - oxalic acid - succinic acid - adenosine triphosphate - pyrophosphate - porphyrins - and proteins.
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
44. What two types of compounds are joined with an ester bond to make a wax?
Degradation of protein and production of acid from sugar at the same time.
Gliadins and Glutenins
Fatty Acid and Alcohol
Lipase
45. Give one word for a carbon atom involved in hemiacetal or acetal formation.
They act as catalysts - speeding the polymerization of acrylamide.
.05
Tryptophan
Anomeric
46. Which amino acid has the greatest molecular weight: tryptophan or tyrosine?
Thermus Aqauticus
Non-protein nitrogen
2.5
Tryptophan
47. Name a commonly used household chemical leavening agent and the gas it generates.
Sodium bicarbonate generates CO2
V=IR and P=VI or I x I x are
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
NaCl (it dissociated to a 2M solution)
48. What is the structural difference between chlorophyll and chlocophyllide?
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
.05
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Chlocophyllide does not have a phytoltail
49. What are the primary secondary - tertiary - and quaternary structures?
RNA transcribed to DNA
Sucrose
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.
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.
50. Name a commonly used household chemical leavening agent and the gas it generates.
It explodes
Plasmids
Sodium bicarbonate generates CO2
Nucleation or crystal formation and crystal growth.