Test your basic knowledge |

Food 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 does Reichert-Meissert Number measure?
Aspartic Acid and Phenylalanine
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
Lipase
Primary butyric acid also caproic acid.

2. What are proteins which are soluble in 50-80% ethanol known as?
Browning of freshly cut surfaces of fruits and vegetables.
Sucrose
Water
Prolamines

3. Name 3 physical agents capable of denaturing proteins.
Heat - Cold Mechanical Treatments - Hyrdostatic Pressure - Irradiation - and Interfaces
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Carmelization and Maillard
The speed of a molecule is proportional to the surrounding voltage gradient.

4. Name two non-enzymatic browning reactions.
Carmelization and Maillard
It explodes
Aspartic Acid and Phenylalanine
Water

5. What is surimi?
Polyphenol Oxidase
Polyphenols
A concentrate of microfibrillar proteins of fish muscle.
Lycopenes

6. Give one word for a carbon atom involved in hemiacetal or acetal formation.
Anomeric
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Parabens
Erythorbic Acid

7. Name two non-enzymatic browning reactions.
Emulsification
Tryptophan
Glycosides of anthocyanidins
Carmelization and Maillard

8. Which will be coldest at its freezing point: 1M dispersion of amylose 1M solution of NaCl - distilled water - or 1M solution of sucrose?
Non-protein nitrogen
Acsulfame-K - Saccharin - Cyclamate - Aspartame
NaCl (it dissociated to a 2M solution)
.05

9. What charge will a protein have when the pH of its solution is below at - and above its pKa?
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.
Oil in Water
pH below positive charge; pH at no charge; pH above negative charge
Prolamines

10. What is the movement of molecules through a semi permeable membrane from a region of low to high solute concentration called?
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
Osmosis
Two aldehydes
Ammonia - Water - Carbon Dioxide

11. What does the acronym NPN stand for?
Ascorbic Acid and Citric Acid
Non-protein nitrogen
Polyphenol Oxidase
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.

12. At low water activity What is the main deteriorative concern?
Lipid oxidation
Phenylketonuria
Pectin methylesterase & polygalacturonase
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).

13. What is Ohm's Law and What is Power Equation?
Butter= water in oil Mayonnaise= oil in water Milk= oil in water
.05 M HCL
V=IR and P=VI or I x I x are
NaCl (it dissociated to a 2M solution)

14. An emulsifier with a high hydrophilic-lipophilic balance (HLB) value would promote which type of emulsion: oil in water or water in oil?
Sucrose
Carmelization and Maillard
Pheophytin forms
Oil in Water

15. Name a naturally occurring protein sweetener.
Thamautin
Sodium bicarbonate generates CO2
Pectin methyl esterase or galacturonase
Milk

16. What is catalase?
An enzyme that converts hydrogen peroxide to water plus oxygen.
Bright green
Aspartic Acid and Phenylalanine
Proportion of solids in the fat - number - size - and kinds of crystals - viscosity of the liquid - temperature treatment - and mechanical working.

17. What metabolic disorder prevents conversion of phenulalanine to tyrosine by normal metabolic pathways?
Negative log of the hydrogen concentration (mol/l).
Polyphenol Oxidase
Phenylketonuria
V=IR and P=VI or I x I x are

18. Name 4 advantages of using enzymes in food processing.
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
Thamautin
Gossypol (it is removed during the oil refining process)
Lipase - lipoxygenase - catalase - chlorophylase - peroxidase - pectinase - protease - ascorbic acid oxidase - alkaline phosphotase.

19. In what food is butyric acid typically found?
20 carbons and 4 double bonds
Milk
A concentrate of microfibrillar proteins of fish muscle.
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.

20. Name the strongest biochemical bond and the weakest biochemical bond.
45% - 52% - 90%
Covalent (strongest) and Hydrophobic (Weakest)
The speed of a molecule is proportional to the surrounding voltage gradient.
14

21. How many carbon atoms are there in the fatty acid myristic acid?
14
Cooling the oil and filtering of the solids formed so that long chained saturated fats do not crystallize at low temperatures.
Lysine - Arginine - and Histidine
Pheophytin forms

22. Alar is the trade name for what chemical compound?
Olive Green
HPLC has higher pressure than FPLC
Daminozide
.05 M HCL

23. What is the Peroxide Value a measure of?
45% - 52% - 90%
Ascorbic Acid and Citric Acid
Yellow
Fat Oxidation

24. What is surimi?
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.
RNA transcribed to DNA
A concentrate of microfibrillar proteins of fish muscle.
Browning of freshly cut surfaces of fruits and vegetables.

25. What are soluble polymers of anhydro-galacturonic acid and its esters called?
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Linoleic Acid
Speed of Light
Pectins

26. What are the three main steps in the autooxidation of lipids?
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Phenophylin
Initiation - Propagation - Termination
The speed of a molecule is proportional to the surrounding voltage gradient.

27. What are the only phenols approved for use in the microbiological preservation of foods?
Parabens
Racemic Mixture
Tryptophan
Blue pigment in flowers

28. Is a disaccharide
Sucrose
Plasmids
RNA transcribed to DNA
Pectin methylesterase & polygalacturonase

29. 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.
Phenylketonuria
Glycosides of anthocyanidins
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.

30. What ketohexose is most significant to food chemists?
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Fructose
4:0 (Butyric) - 10:0 (Capric) - 12:0 (Lauric) - 14:0 (Myristic) - 16:0 (Palmitic) - 18:0 (Stearic)
Thamautin

31. What metabolic end product does the Voges-Proskauer test detect?
Acetoin
The amount of unsaturated bonds in fat; grams Iodine reacting with 100 grams fat.
Gliadins and Glutenins
Daminozide

32. What are soluble polymers of anhydro-galacturonic acid and its esters called?
Water
Corn- Lysine - Potato-Methionine - Green Peas-Methionine
2-mercaptoethanol (2-ME) - dithiothreitol (DDT)
Pectins

33. What does the 'c' stand for in the equation E=mc2?
Anthocyanins
Speed of Light
Decreased solubility - altered water-binding capacity - loss of biological activity - increased susceptibility to attack by proteases - increased intrinsic viscosity - inability to crystallize.
Primary butyric acid also caproic acid.

34. What is the chemical nature of anthocyanins?
Glycosides of anthocyanidins
For proteins: SDA-PAGE. For DNA & RNA: Agarose gel.
Solid phases of the same chemical composition that differ by crystalline structure - but yield identical liquid phases upon melting.
Phenylketonuria

35. Which two amino acids is the aspartame derived from?
Aspartic Acid and Phenylalanine
.05
Racemic Mixture
Osmosis

36. If the absorption of a sample is being determined spectrophotometrically at 420 nm what color is the sample?
Phenylketonuria
RNA transcribed to DNA
Yellow
Lipase

37. When heated ammonium bicarbonate decomposes to form what end products?
Polyphenol Oxidase
Gliadins and Glutenins
Lipid oxidation
Ammonia - Water - Carbon Dioxide

38. If oxygen attacks an unsaturated fatty acids at the double bond What is the resultant product?
Two aldehydes
Fructose
Blue pigment in flowers
Erythorbic Acid

39. How many polypeptide chains make up an antibody?
Ammonia - Water - Carbon Dioxide
Four
Fructose
Carmelization and Maillard

40. At what pH is benzoic acid most effective?
pH 3-5
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.
Water
Osmosis

41. What is the name of the structural carbohydrate found in lobsters crab - shellfish - and insects?
Fatty Acid (Ester linked) to Fatty Alcohol
Chitin
Bright green
RNA transcribed to DNA

42. What is the geometric configuration of double bonds in most natural fatty acids?
Cis
HPLC has higher pressure than FPLC
pH 3-5
No

43. 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.
RNA transcribed to DNA
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.
Pectins

44. What effect would the addition of sodium bicarbonate have to chocolate?
Smoother - less acid and less bitter chocolate flavor - darker color - and improved solubility (elevated pH enhances sugar-amino browning reactions and polymerization of flavonoids).
Olive Green
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
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.

45. What does HLB stand for and What does a high and low HLB value indicate?
Emulsification
Sodium chloride reduces foam stability and sucrose improves foam stability.
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.
Cis

46. 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
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.
Temperature - Water Content and Activity - Extremes of pH - Chemicals - Alterations of Substrates - Alterations of Products - Preprocessing Controls
Pectin methylesterase & polygalacturonase

47. Name two enzymes that are involved in softening fruits.
Pectin Esterase - Polygalacturonase - Pectin Layase
Daminozide
Number of fatty acids present; mg KOH needed to saponify 1 g fat.
Polyphenol Oxidase

48. How many carbon atoms and how many double bonds are there in arachidonic acid?
Speed of Light
Initiation - Propagation - Termination
20 carbons and 4 double bonds
Plasmids

49. In polyacrylamide gel electrophoresis (PAGE) what purpose do ammonium persulfates (APS) and TEMED serve?
Polyphenols
Thamautin
They act as catalysts - speeding the polymerization of acrylamide.
Degradation of protein and production of acid from sugar at the same time.

50. What are 3 mesomorphic structures associated with lipids in the liquid state?
Phospholipids - water - sulfur compounds - soaps - partial glycerol esters - carbon dioxide - and mineral acids.
Water
Lamellar; Hexagonal I - II; Cubic
20 carbons and 4 double bonds