AP Biology - Biochemistry Exam
1. There are 20 different amino acids in the proteins that make up the tissues of living organisms. The primary difference between these amino acids is in their: A. R or variable groups. B. Number of potassium groups C. Number of phosphate groups D. Number of asymmetric carbons.
A
16. a 5' carbon of deoxyribose
A
21. The products of the figure above are: A. monosaccharides B. molecules of glycerol C. representative of a glycosidic linkage D. enzymes
A
22. Which of the following pictures and descriptions shows the formation of polymers? A. Figure 1, which shows dehydration synthesis. B. Figure 1, which shows hydrolysis. C. Figure 2, which show dehydration synthesis D. Figure 2 which shows hydrolysis
A
6. The bonding of two amino acid molecules to form a larger molecule requires A. the release of a water molecule B. the release of a carbon dioxide molecule C. the addition of a nitrogen atom D. the addition of a water molecule
A
7. Animals produce most of their nitrogen-containing wastes during A. protein digestion B. carbohydrate digestion C. lipid digestion D. glycogen synthesis
A
Directions: Each group of questions in this section consists of five lettered choices followed by a list of numbered phrases or sentences. For each numbered phrase or sentence select the one heading that is most closely related to it and fill in your choice in the blank. Each lettered choice may be used once, more than once, or not at all in each group. For Questions 9-12, refer to the following list of biomolecules. A. Proteins B. Carbohydrates C. Nucleic Acids D. Lipids E. Steroids 9. Includes molecules that function as cellular signals, receptors, enzymes, transporters and carriers.
A
Questions 24 and 25 refer to the figure below. The figure below shows the calories of heat energy required to convert a gram of water from solid to liquid state, and then again from liquid to solid state. Especially distinctive is the large increase in the energy required to move water from liquid to gas form. 24. The graph depicts which of the following properties of water that would affect plant survival? A. Plant leaves doing transpiration are cooled down on hot days. B. Inside a plant stem, cohesion attracts one water molecule to the water molecule above it, allowing a "chain" of water molecules to move up the stem. C. At a plant's roots, adhesion attracts water molecules to "stick" to root hairs, aiding absorption. D. Sugar will dissolve in water, leading to a plant fluid called phloem, which typically flows from the leaves, down towards the roots.
A
23. If the differently shaded portions of this molecule represent different polypeptide chains, then this figure is representative of: A. an amino acid B. the quaternary structure of a protein C. a steroid hormone D. A carotenoid
B
5. Which of the following pairs of functional groups characterizes the structure of an amino acid?
B
A. Proteins B. Carbohydrates C. Nucleic Acids D. Lipids E. Steroids 10. Includes glycogen, chitin, cellulose and glucose.
B
For questions 13 through 17, refer to the following diagram of an organic molecule. 13. A chemical group that, together with a sugar and a nitrogen base, makes up a nucleotide
B
2. The nitrogenous base, adenine, is found in which three of the following? A. Proteins, chlorophyll, and vitamin A. B. Protein, ATP, and DNA. C. ATP, DNA, and RNA. D. Chlorophyll, ATP and DNA
C
27. If 14C-labeled uracil is added to the growth medium of cells, what macromolecules will be labeled? A. phospholipids B. DNA C. RNA D. both DNA and RNA
C
3. A feature of organic compounds NOT found in inorganic compounds is the presence of A. Ionizing chemical groups B. Electrons C. Carbon atoms covalently bonded to each other. D. Oxygen
C
30. A compound contains hydroxyl groups as its predominant functional group. Which of the following statements is true concerning the compound? A. It lacks an asymmetric carbon and is probably a fat or lipid. B. it is hydrophobic C. it is probably an alcohol. D. It won't form hydrogen bonds with water.
C
4. Which of the following is a correct statement about the relationship between pH and the hydrogen ion concentration of a solution? A. There are no hydrogen ions present in a solution with a basic pH. B. There are no hydrogen ions present in a solution with a neutral pH of 7.0. C. The concentration of hydrogen ions in a solution with a pH of 7.0 is 100 times as great as that in a solution with a pH of 9.0. D. The concentration of hydrogen ions in a solution with a pH of 5.0 is twice as great as that in a solution with a pH of 3.0.
C
8. Which of the following is responsible for the cohesive property of water? A. Hydrogen bonds between the oxygen atoms of two adjacent water molecules B. Covalent bonds between the hydrogen atoms of two adjacent water molecules C. Hydrogen bonds between the oxygen atom of one water molecule and a hydrogen atom of another water molecule D. Covalent bonds between the oxygen atom of one water molecule and a hydrogen atom of another water molecule
C
A. Proteins B. Carbohydrates C. Nucleic Acids D. Lipids E. Steroids 12. Used to carry the genetic code.
C
Questions 20 and 21 refer to the figure below. 20. The process illustrated above is called: A. condensation B. protein synthesis C. hydrolysis D. denaturation
C
15. A Pyrimidine
D
18. Which of the following statements most correctly represents the organization of living systems from smallest to largest? (A) Molecules → organs → cells → organisms (B) Cells → tissues → molecules → ecosystems → communities (C) Organisms → molecules → cells → atoms (D) Atoms → molecules → cells → organisms → ecosystems
D
19. The tertiary structure and function of a polypeptide is principally determined by the. A. Length of the polypeptide B. number of nucleotides present in the polypeptide. C. repeated units of glycerol making up the polypeptide. D. interactions between amino acids present in the polypeptide. E. number of introns within the polypeptide.
D
25. Why does the graph above show a dramatic increase in energy required to convert liquid water to water vapor? A. liquid water has a high heat capacity, and therefore adheres to cooler surfaces. This adhesion leads to a strong attraction of water to any non-water molecule. B. Liquid water is an excellent solvent, and contains many solutes (sugar, salt, etc.) that dissolve within it; these solutes must crystallize and come out of solution in order for liquid water to turn into water vapor. C. liquid water is polar, and thus aligns molecules on a north-south axis; energy must be added to reverse polarity of water and allow individual water molecules to become vaporized. D. Liquid water is held together by hydrogen bonds between the water molecules; these bonds must become energized and break so evaporation can happen.
D
28. Why does ice float in liquid water? A. the high surface tension of liquid water keep the ice on top. B. the ionic bonds between the molecules in ice prevent the ice from sinking. C. Ice always has air bubbles that keep it afloat. D. hydrogen bonds stabilize and keep the molecules of ice farther apart than the water molecules of liquid water. E. the crystalline lattice of ice causes it to be denser than liquid water.
D
29. How many electrons pairs does carbon share in order to complete its valence shell? A. 1 B. 2 C. 3 D. 4
D
A. Proteins B. Carbohydrates C. Nucleic Acids D. Lipids E. Steroids 11. Used for insulation and buoyancy in marine Artic animals.
D
14. a hydrogen bond.
E
17. Most likely to be broken during replication.
E
26. Normal hemoglobin is a tetramer, consisting of two molecules of α hemoglobin and two molecules of β hemoglobin. In sickle-cell disease, as a result of a single amino acid change, the mutant hemoglobin tetramers associate with each other and assemble into large fibers. Based on this information alone, we can conclude that sickle-cell hemoglobin exhibits A. altered primary structure B. altered secondary structure C. altered tertiary structure D. altered quaternary structure E. altered primary structure and altered quaternary structure; the secondary and tertiary structures may or may not be altered.
E