End of chapter
5.Lipid-soluble signaling molecules, such as testosterone, cross the membranes of all cells but affect only target cells because __________.
intracellular receptors are present only in target cells
9.The drug cytochalasin B blocks the function of actin. Which of the following aspects of the animal cell cycle would be most disrupted by cytochalasin B?
cleavage furrow formation and cytokinesis
13. In a nucleosome, the DNA is wrapped around ________
histones
3.e structural level of a protein least affected by a disruption in hydrogen bonding is th
primary level.
2.A slice of pizza has 500 kcal. If we could burn the pizza and use all the heat to warm a 50-L container of cold water, what would be the approximate increase in the temperature of the water? (Note: A liter of cold water weighs about 1 kg.)
10 degrees C
2.Measurements show that the pH of a particular lake is 4.0. What is the hydrogen ion concentration of the lake?
10-4 M
10.How many different combinations of maternal and paternal chromosomes can be packaged in gametes made by an organism with a diploid number of 8 (2n = 8)?
16
2.What coefficients must be placed in the following blanks so that all atoms are accounted for in the products?
2; 2
10. If the DNA content of a diploid cell in the G1 phase of the cell cycle is x, then the DNA content of the same cell at metaphase of meiosis I would be
2x.
9. A particular cell has half as much DNA as some other cells in a mitotically active tissue. The cell in question is most likely in
: G1.
5.Which of the following processes includes all the others?
: passive transport
13.In analyzing the number of different bases in a DNA sample, which result would be consistent with the base-pairing rules?
A + G = C + T
8.The light reactions of photosynthesis supply the Calvin cycle with __________.
ATP and NADPH
8.Which of the following statements is a correct distinction between autotrophs and heterotrophs?
Autotrophs, but not heterotrophs, can nourish themselves beginning with CO2 and other nutrients that are inorganic.
3. hich of the following hydrocarbons has a double bond in its carbon skeleton?
C2H4
3. The molecular formula for glucose is C6H12O6. What would be the molecular formula for a polymer made by linking ten glucose molecules together by dehydration reactions?
C60H102O51
3.Which of the following categories includes all others in the list?
Carbohydrate
5.In what way do the membranes of a eukaryotic cell vary?
Certain proteins are unique to each kind of membrane.
13. What is the basis for the difference in how the leading and lagging strands of DNA molecules are synthesized?
DNA LIGASE JOINS AT 3' END OF GROQING STAND
13.A biochemist isolates, purifies, and combines in a test tube a variety of molecules needed for DNA replication. When she adds some DNA to the mixture, replication occurs, but each DNA molecule consists of a normal strand paired with numerous segments of DNA a few hundred nucleotides long. What has she probably left out of the mixture?
DNA ligas
7.he immediate energy source that drives ATP synthesis by ATP synthase during oxidative phosphorylation is the __________.
H+ movement down its concentration gradient
2.The atomic number of sulfur is 16. Sulfur combines with hydrogen by covalent bonding to form a compound, hydrogen sulfide. Based on the number of valence electrons in a sulfur atom, predict the molecular formula of the compound.
H2S
4.hich structure is NOT part of the endomembrane system
Hloroplast
8.How is photosynthesis similar in C4 plants and CAM plants?
In both cases, rubisco is not used to fix carbon initially.
4.yanide binds to at least one molecule involved in producing ATP. If a cell is exposed to cyanide, most of the cyanide will be found within the ________
Mitochondria
4.hich structure is common to plant and animal cells
Mitochondrion
6.Most cells CANNOT harness heat to perform work because _________
Most cells CANNOT harness heat to perform work because _________
6.If an enzyme is added to a solution where its substrate and product are in equilibrium, what will occur?
Nothing; the reaction will stay at equilibrium.
4.Which of the following is present in a prokaryotic cell
Ribosome
7.When electrons flow along the electron transport chains of mitochondria, which of the following changes occurs?
The pH of the matrix increases.
2.Which of the following statements correctly describes any chemical reaction that has reached equilibrium?
The rates of the forward and reverse reactions are equal.
5.Which of the following factors would tend to increase membrane fluidity?
a greater proportion of unsaturated phospholipids
9.Through a microscope, you can see a cell plate beginning to develop across the middle of a cell and nuclei forming on either side of the cell plate. This cell is most likely
a plant cell in the process of cytokinesis.
10.A human cell containing 22 autosomes and a Y chromosome is
a sperm.
6. If an enzyme in solution is saturated with substrate, the most effective way to obtain a faster yield of products is to __________.
add more of the enzyme
3.Which chemical group is most likely to be responsible for an organic molecule behaving as a base (see Concept 2.5)?
amino
9.In the cells of some organisms, mitosis occurs without cytokinesis. This will result in
cells with more than one nucleus.
13.The elongation of the leading strand during DNA synthesis __________.
depends on the action of DNA polymeras
5.Based on the figure given below, which of these experimental treatments would increase the rate of sucrose transport into the cell?
decreasing extracellular pH
4.hat is the most likely pathway taken by a newly synthesized protein that will be secreted by a cell
er to golgi to vesicles
6.Choose the pair of terms that correctly completes this sentence: Catabolism is to anabolism as __________ is to __________
exergonic; endergonic
7.Which metabolic pathway is common to both fermentation and cellular respiration of a glucose molecule?
glycolysis
8.Which of the following sequences correctly represents the flow of electrons during photosynthesis?
h20-nadph-calvin cycle
4.hich structure-function pair is MISMATCHED?
icrotubule; muscle contraction
10Homologous chromosomes move toward opposite poles of a dividing cell during
meiosis I.
13. The spontaneous loss of amino groups from adenine in DNA results in hypoxanthine, an uncommon base, opposite thymine. What combination of proteins could repair such damage?
nuclease, DNA polymerase, DNA ligase
2.We can be sure that a mole of table sugar and a mole of vitamin C are equal in their __________.
number of molecules
13.E. coli cells grown on 15N medium are transferred to 14N medium and allowed to grow for two more generations (two rounds of DNA replication). DNA extracted from these cells is centrifuged. What density distribution of DNA would you expect in this experiment?
one low-density and one intermediate-density band
8.In mechanism, photophosphorylation is most similar to __________
oxidative phosphorylation in cellular respiration
7.The final electron acceptor of the electron transport chain that functions in aerobic oxidative phosphorylation is __________
oxygen
4.Which cell would be best for studying lysosomes?
phagocytic white blood cell
6.Which of the following metabolic processes can occur without a net influx of energy from some other process?
phoosynthesis
7.In mitochondria, exergonic redox reactions __________.
provide the energy that establishes the proton gradient
7.What is the oxidizing agent in the following reaction?
pyruvate
8.Which of the following does NOT occur during the Calvin cycle
release of oxygen
8.Which process is most directly driven by light energy?
removal of electrons from chlorophyll molecules
9.Which of the following does not occur during mitosis?
replication of the DNA
13. In his work with pneumonia-causing bacteria and mice, Griffith found that __________.
some substance from pathogenic cells was transferred to nonpathogenic cells, making them pathogenic
3.Which functional group is not present in this molecule? Which functional group is not present in this molecule?
sulfhydryl
2.Many mammals control their body temperature by sweating. Which property of water is most directly responsible for the ability of sweat to lower body temperature?
the absorption of heat by the breaking of hydrogen bonds
7.Most CO2 from catabolism is released during __________.
the citric acid cycle
2.The reactivity of an atom arises from __________.
the existence of unpaired electrons in the valence shell
6.Some bacteria are metabolically active in hot springs because __________.
their enzymes have high optimal temperatures
5. Phosphorylation cascades involving a series of protein kinases are useful for cellular signal transduction because __________.
they amplify the original signal manyfold
10.If we continued to follow the cell lineage from question 3, then the DNA content of a single cell at metaphase of meiosis II would be
x.
