Practice Questions - Food

1. Amino acid monomers are joined to make a polypeptide chain by
(A) an acid-base reaction
(B) formation of a peptide bond
(C) splitting out a water molecule
(D) all of the above

2. Which of the following is an ether?
(A) CH₃-CH₂-CH₂-COOH
(B) CH₂=CH-CH₂-CH₃
(C) CH₃-CH₂-CH₂-O-CH₂-CH₂-CH₃
(D) CH₃-CH₂-OH
(E) CH₃-CH₂-CH₃

3. Which of the following is the chief source of the element nitrogen in our diet?
(A) protein
(B) carbohydrates
(C) fat
(D) sugar
(E) vitamin N

4. A dipeptide is made of two amino acids. Assuming that there are 20 amino acids to choose from, how many different tripeptides are possible?
(A) 20
(B) 40
(C) 444
(D) 400
(E) 20, 000

5. A tripeptide is made of three amino acids. Assuming that there are 20 amino acids to choose from, how many different tripeptides are possible?
(A) 20
(B) 60
(C) 23
(D) 8, 000
(E) 20, 000

6. The most common monosaccharide is
(A) starch
(B) cellulose
(C) sucrose
(D) glucose

7. Carbohydrates, proteins, and DNA are all
(A) C, H, and O compounds only
(B) inorganic compounds
(C) polymers
(D) helical structures

8. The monomers in proteins are
(A) monosaccharides
(B) amino acids
(C) nucleic acids
(D) all optically active

9. Which is NOT an organic functional group characteristic of carbohydrates?
(A) CHO
(B) OH
(C) -C-C-
(D) NH

10. The amount of energy necessary to raise the temperature of 1 gram of liquid water by 1 degree Celsius
(A) is one kilocalorie.
(B) is 1,000 calories.
(C) depends on the initial temperature of the water sample.
(D) is one calorie.
(E) is one Calorie.

11. Citric acid makes lemons taste sour. Which of the following is a functional group that would cause a molecule like citric acid to be acidic?
(A) hydroxyl
(B) carboxyl
(C) amino
(D) hydrocarbon
(E) carbonyl

12. Which of the following is NOT a sugar?
(A) fructose
(B) glucose
(C) ribose
(D) sucrose
(E) ethanol

13. Which is the best description of a triglyceride?
(A) three glycerol molecules connected together
(B) three fatty acids connected to a single glycerol molecule
(C) three amino acids connected to three glycerol molecules
(D) a long hydrocarbon chain containing three double bonds
(E) a chain of three glucose molecules

14. Which of the following is composed of amino acids?
(A) starch
(B) DNA
(C) enzymes
(D) carbohydrates
(E) vitamin C

15. Which of these is a monosaccharide?
(A) sucrose
(B) starch
(C) glycogen
(D) glucose
(E) cellulose

16. What is the difference between saturated and unsaturated fats?
(A) only unsaturated fats can be converted into cholesterol
(B) saturated fats sink when placed in water
(C) unsaturated fats contain at least one C=C double bond
(D) saturated fats contain twice the calories of unsaturated fats
(E) the human body can only synthesize unsaturated fats

17. Which of the following is a trace element, required only in small amounts by most living things?
(A) oxygen
(B) hydrogen
(C) carbon
(D) nitrogen
(E) iron

18. The building blocks for proteins are
(A) amino acids.
(B) fatty acids and glycerol.
(C) monosaccharides.
(D) disaccharides.
(E) nucleic acids.

19. Glucose and hexanoic acid each contain six carbon atoms, but they have completely different properties. Glucose is necessary in food; hexanoic acid is poisonous. Their differences must be due to different
(A) macromolecules.
(B) hydrolysis.
(C) monomers.
(D) functional groups
(E) quaternary structures.

20. Which is NOT a valid means of food preservation?
(A) adding a heavy concentration of NaCl
(B) adding a heavy concentration of sugar
(C) refrigeration
(D) pounding with a hammer
(E) irradiation

21. Which of the following statements is NOT correct?
(A) vitamins are organic compounds
(B) vitamins are needed in only small amounts
(C) all vitamins are soluble in fatty tissue
(D) a prolonged vitamin deficiency will usually result in a health problem
(E) Vitamin C is also known as ascorbic acid

22. Which of the following makes up the largest fraction of the human body?
(A) fats
(B) proteins
(C) carbohydrates
(D) water
(E) vitamin C

23. Which of the following is needed in the smallest quantity each day?
(A) Vitamin C
(B) fats
(C) carbohydrates
(D) proteins
(E) amino acids

24. Which molecule contains a triple bond?
(A) propane
(B) ethylene
(C) acetic acid
(D) methyl ethyl ketone
(E) butyne

25. Which of the following is NOT a polymer?
(A) glycine
(B) teflon
(C) starch
(D) polystyrene
(E) protein

26. The combustion of glucose (C₆H₁₂O₆) releases 2800 kJ/mol. What is the correct heat content of glucose?
(A) 2.8 kJ/g
(B) 15.6 kJ/g
(C) 2, 800 kJ/g
(D) 180 kJ/g
(E) 156 kJ/g

27. The large diversity of shapes of biological molecules is possible because of the extensive presence of
(A) nitrogen.
(B) hydrogen
(C) sulfur.
(D) carbon.
(E) oxygen.

28. Although the structure of specific functional groups varies, they all share one thing in common: They
(A) all are hydrophilic and increase the organic compound's solubility.
(B) unite the skeleton into a closed ring.
(C) all have at least one double bond.
(D) cause the carbon to which they are attached to become an asymmetric carbon, and convert the molecule into an enantiomer.
(E) all contain oxygen.


ANSWERS

1-D 2-C 3-A 4-D 5-D 6-D 7-C 8-B 9-D 10-D 11-B 12-E 13-B 14-C 15-D 16-C 17-E 18-A 19-D 20-D 21-C 22-D 23-A 24-E 25-A 26-B 27-D 28-A