Which of the following analogies best describes the induced-fit model of enzyme-substrate binding? A) Lock and key model B) Handshake model C) Glove and hand model D) Rigid mold model
C) Glove and hand model. The induced-fit model suggests that the enzyme changes shape to fit the substrate more snugly, similar to how a glove molds to fit a hand.
Which graph shows the reaction if an enzyme were present? A) A graph with a lower activation energy peak B) A graph with a higher activation energy peak C) A graph with no change in activation energy D) A graph with a flat line
A) A graph with a lower activation energy peak. Enzymes lower the activation energy of a reaction, making it proceed faster.
What do both the rho-dependent and rho-independent mechanisms of termination have in common? A) They both require a rho protein B) They both involve the formation of a hairpin loop C) They both occur in eukaryotes D) They both terminate transcription
D) They both terminate transcription. Both mechanisms are involved in ending the process of transcription in prokaryotes.
What is the role of the reaction center in a photosystem? A) To absorb light and transfer energy to the electron transport chain B) To synthesize ATP directly C) To fix carbon dioxide D) To release oxygen
A) To absorb light and transfer energy to the electron transport chain. The reaction center is crucial for capturing light energy and initiating electron transfer.
Which of the following statements best describes the induced fit model of enzyme activity? A) Enzymes are rigid structures that do not change shape B) Enzymes change shape to better fit the substrate C) Enzymes are destroyed after the reaction D) Enzymes work only with one specific substrate
B) Enzymes change shape to better fit the substrate. The induced fit model suggests that enzymes are flexible and adjust their shape to bind substrates more effectively.
Which of the following is not a mechanism of evolution? A) Natural selection B) Genetic drift C) Mutation D) Photosynthesis
D) Photosynthesis. Photosynthesis is a biological process, not a mechanism of evolution.
Which graph shows the reaction of an enzyme were present? A) A graph with a lower activation energy peak B) A graph with a higher activation energy peak C) A graph with no change in activation energy D) A graph with a flat line
A) A graph with a lower activation energy peak. Enzymes lower the activation energy of a reaction, facilitating a faster reaction rate.
Which is the correct depiction of the transition state for the reaction shown below? A) A structure with partial bonds B) A structure with full bonds C) A structure with no bonds D) A structure with broken bonds
A) A structure with partial bonds. The transition state is characterized by partial bonds as the reaction progresses from reactants to products.
Which of the following mechanisms of evolution is not a source of new alleles for a population? A) Mutation B) Gene flow C) Genetic drift D) Natural selection
C) Genetic drift. Genetic drift is a mechanism of evolution that changes allele frequencies but does not introduce new alleles.
What type of bonds are broken during the unwinding stage of replication? A) Covalent bonds B) Hydrogen bonds C) Ionic bonds D) Metallic bonds
B) Hydrogen bonds. During DNA replication, hydrogen bonds between the base pairs are broken to allow the strands to separate.
Which of the following is best associated with a coupled reaction? A) ATP hydrolysis B) Photosynthesis C) Glycolysis D) Fermentation
A) ATP hydrolysis. Coupled reactions often involve ATP hydrolysis to drive endergonic processes.
Which of the following is correct about the polyadenylation mechanism? A) It adds a cap to the 5' end of mRNA B) It removes introns from mRNA C) It adds a poly-A tail to the 3' end of mRNA D) It splices exons together
C) It adds a poly-A tail to the 3' end of mRNA. Polyadenylation is the process of adding a poly-A tail to mRNA, which is important for stability and export from the nucleus.