AP Biology Multiple Choice Midterm Study Guide

Which of the following best depicts the tertiary structures of the two proteins in water? The diagrams in the options are not drawn to the same scale as those in Figure 1 and Figure 2.

A)

Which of the following correctly illustrates a dipeptide and an amino acid in the optimal position to form a tripeptide?

A)

Which of the following best explains why bile salts cause the sulfur powder to sink?

A) Bile salts decrease the surface tension of the urine sample.

Based on the data, which structural domain is most likely required for DNA binding?

A) Domain F

Which of the following best explains why a cell's plasma membrane is composed of two layers of phospholipids rather than just a single layer?

A) Having two oppositely oriented layers of phospholipids allows only the hydrophilic heads to interact with water inside and outside of the cell.

Which of the following types of bonds is most likely responsible for the unusual base pairing shown in Figure 3 that results in the formation of a triplex DNA structure?

A) Hydrogen

Based on Figure 1, the amino acids in region A are most likely to have which of the following characteristics?

A) Most amino acids will be hydrophobic because they interact most favorably with the phospholipid tails.

A typical bag of fertilizer contains high levels of nitrogen, phosphorus, and potassium but trace amounts of magnesium and calcium. Which of the following best matches the fertilizer component with the molecule in which it will be incorporated by organisms in the area?

A) Nitrogen will be incorporated into nucleic acids.

Which of the following graphs is the most appropriate representation of the experimental results documented in the table?

B)

Amylase is an enzyme that converts carbohydrate polymers into monomers. Glycogen synthase is one of the enzymes involved in converting carbohydrate monomers into polymers.

B) Amylase aids in the addition of a water molecule to break covalent bonds whereas glycogen synthase aids in the removal of a water molecule to form covalent bonds.

Which of the following best supports the researcher's claim?

B) Guanine-cytosine pairs denature at a higher temperature because they have more hydrogen bonds between them than adenine-thymine pairs do.

Which of the following statements best describes how organisms such as rabbits obtain the carbon necessary for building biological molecules?

B) Rabbits eat plants and break down plant molecules to obtain carbon and other atoms that they rearrange into new carbon-containing molecules.

Which of the following claims is best supported by the data in Table 1 ?

B) Sample B contains protein.

Which of the following is the most likely result at the completion of the project?

B) The biomass of coyotes will be dramatically reduced.

Which of the following best describes the effect of a greater number of cysteine amino acids on the stability of the proteins?

B) The change leads to increased protein stability because of an increased number of S-S bonds in the tertiary structure of the proteins.

Humans produce sweat as a cooling mechanism to maintain a stable internal temperature. Which of the following best explains how the properties of water contribute to this physiological process?

B) The high heat of vaporization of water allows the body to remove excess heat through a phase change of water from liquid to gas.

Which of the following best describes how amino acids affect the tertiary structure of a protein?

B) The interactions of the different R-groups with other R-groups and with their environment determine the tertiary structure of the protein.

Which statement best helps explain the formation of the hydrogen bond represented in the figure?

B) The nitrogen has a partial negative charge, and the hydrogen attached to the oxygen has a partial positive charge.

A chemical binds to a protein composed of a single polypeptide chain and prevents the formation of an alpha helix that is typically formed in the absence of the chemical. Which of the following best describes the effect the chemical has on the structure of the protein?

B) The secondary structure held together by hydrogen bonds is affected.

Which of the following most likely explains how the amino acid substitution has resulted in decreased catalytic activity by the mutated enzyme?

B) The substitution altered the secondary and tertiary structure of the enzyme so that the mutated enzyme folds into a different shape than the normal enzyme does.

Which of the following best describes the structures of carbohydrates?

B) They occur as monomers, chains of monomers, and branched structures.

Ultraviolet (UV) radiation can damage DNA by breaking weak bonds. Which of the following best explains how this occurs?

B) UV radiation disrupts the double helix structure by breaking the hydrogen bonds between the nitrogenous base pairs.

Which of the following best describes the formation of the bond shown in Figure 1?

C) A covalent bond is formed between a carbon atom and a nitrogen atom along with the formation of H2O

Based on the results of the experiment, which of the following types of molecules did the bacteriophages most likely inject into the bacteria cells?

C) DNA

Which of the following best describes the process by which gas from the atmosphere is obtained by plants and used to build lipids?

C) Gas is directly obtained by plants as part of the carbon cycle.

Which of the following is responsible for the cohesive property of water?

C) Hydrogen bonds between the oxygen atom of one water molecule and a hydrogen atom of another water molecule.

The amino acid in Figure I is found in a region of a polypeptide that folds away from water. Which part of the amino acid most likely contributes to the hydrophobic behavior of this region of the polypeptide?

C) Methyl (CH) group

Scientists examined the folded structure of a purified protein resuspended in water and found that amino acids with nonpolar R groups were primarily buried in the middle of the protein, whereas amino acids with polar R groups were primarily on the surface of the protein. Which of the following best explains the location of the amino acids in the folded protein?

C) Nonpolar R groups that cannot form hydrogen bonds with water are pushed into the middle of the protein.

Used to carry the genetic code

C) Nucleic acids

Based on the molecular structures shown in the figure, which molecule is likely to be solid at room temperature?

C) Palmitic acid, because the absence of carbon-carbon double bonds allows the molecules to pack closely together.

Which of the following best describes the hydrolysis of carbohydrates?

C) The addition of a water molecule breaks a covalent bond between sugar monomers.

Which of the following statements about glucose, galactose, and fructose is most likely true?

C) The carbohydrates have different properties because they have different arrangements of carbon, hydrogen, and oxygen atoms.

A feature of organic compounds NOT found in inorganic compounds is the presence of

C) carbon atoms covalently bonded to each other

Based on Figure 1, which of the following best describes how the properties of water at an air-water interface enable an insect to walk on the water's surface?

D) Hydrogen bonds between molecules at the surface of the water provide surface tension, which allows the water surface to deform but not break under the insect.

Which of the following is most directly responsible for water's unique properties?

D) It forms hydrogen bonds.

Which of the following best predicts how the amino acid deletion will affect the structure of the OFTR protein?

D) It will affect the primary, secondary, and tertiary structures of the CFTR protein.

Which of the following statements best describes how molecules released by the fish become nutrients for the plants?

D) The ammonia molecules released by the fish are converted by the bacteria to nitrates, which are used by the plants to make proteins and nucleic acids.

Which of the following is an accurate description of the process shown in Figure 1?

D) The formation of a covalent peptide bond in a dehydration synthesis reaction

The diagram shows how water can adhere to the xylem in the stems of plants, which contributes to water movement in the plant. Which of the following best explains how water is able to move upward from the roots of a plant, through its xylem in the stem, and out to the leaves?

D) Water and the xylem are both polar. Water molecules have the ability to form hydrogen bonds with each other and with the walls of the xylem.

The synthesis of protein or carbohydrate polymers always produces which of the following as a byproduct?

E) Water