AP Biology Chapter 8 test
The organism ultimately must obtain all of the necessary energy for life from its environment
For living organisms, which of the following is an important consequence of the first las of thermodynamics?
Energonic
A chemical reaction that has a positive G is correctly described as
Compartmentalization of enzymes into defined organelles
Besides turning enzymes on or off, what other means does a cell use to control enzymatic activity?
A chemical reaction in which both the reactants and products are only used in a metabolic pathway that is completely inactive
Chemical equilibirum is relatively rare in living cells. Which of the following could be an example of a reaction at chemical equilibrium in a cell?
Add a catalyst
How can one increase the rate of a chemical reaction?
By changing the shape of a reactant
How does a noncompetitive inhibitor decrease the rate of an enzyme reaction?
Nothing; the reaction would stay at equilibrium
If an enzyme is added to a solution where its substrate and product are in equilibrium, what would occur?
Add more of the enzyme
If an enzyme solution is saturated with substrate, the most effective way to obtain a faster yield of products is to
From right to left at the bottom of the figure
In coupled reactions, in which direction would the endergonic reaction be driven relative to the clockwise direction of the ATP reaction above and shown in the figure?
As a consequence if growing, organisms create more disorder in their environment than the decrease in entropy associated with their growth
Living organisms increase in complexity as they grow, resulting in a decrease in the entropy of an orgasm. How does this relate to the second law of thermodynamics?
Temperature is usually uniform throughout a cell
Most cells cannot harness heat to perform work because
Activation energy
Reactants capable of interacting to form products in a chemical reaction must first overcome a thermodynamic barrier known as the reaction's
Their enzymes have high optimal temperatures
Some bacteria are metabolically active in hot spring because
Breaking the bond between glucose and fructose and forming new bonds from the atoms of water
Sucrose is a disaccharide, composed of the monosaccharides glucose and fructose. The hydrolysis of sucrose by the enzyme sucrase results in
G is the change in free energy
The mathematical expression for the change in free energy of a system is G = H - TS. Which of the following is correct?
Feedback inhibition
The mechanism in which the end product of a metabolic pathway inhibits an earlier step in the pathway is known as
Energy coupling
What term is used to describe the transfer of free energy from catabolic pathways to anabolic pathways?
It can be added to other molecules in order to activate them
When ATP releases some energy, it also releases inorganic phosphate. What purpose does this serve (if any) in the cell?
It is lost to the environment
When chemical, transport, or mechanical work is done by an organism, what happens to the heat generated?
Entropy of the universe
Whenever energy is transformed, there is always an increase in the
Dehydration reactions
Which if the following types of reactions would decrease the entropy within a cell?
The heat content of a chemical system
Which of the following best describes enthalpy (H)?
No net change
Which of the following describes the change in free energy of a system at a chemical equilibrium?
Vitamins
Which of the following is an example f a coenzyme?
A food molecule made up of energy-rich macromolecules
Which of the following is an example of potential energy rather than kinetic energy?
An RNA nucleotide
Which of the following is most similar in structure to ATP?
ATP is a molecule that acts as an intermediary to store energy for cellular work
Which of the following is the most correct interpretation of the figure?
The reaction proceeds with a net release of free energy
Which of the following is true for all exergonic reactions?
They consume energy to build up polymers from monomers
Which of the following is true for anabolic pathways?
Competitive inhibitors
Which of the following mimics and reduces the productivity of eznymes by blocking substrates from entering active sites?
A multi-enzyme complex contains all the enzymes of a metabolic pathway
Which of the following statements describes ezyme cooperatively?
The reaction is faster than the same reaction in the absence of the enzyme; the free energy change of the reaction is opposite from the reaction in the absence of the enzyme.
Which of the following statements is (are) true about ensyme-catalyzed reactions?
Cells require a constant input of energy to maintain their high level of organization
Which of the following statements is representative of the second law of thermodynamics?
They are usually coupled with anabolic pathways to which they supply energy in the form of ATP
Which of the following statements is true concerning catabolic pathways?
Enzymes increase the rate of a reaction
Which of the following statements regarding enzymes is true?
Catabolism
Which term most precisely describes the cellular process of breaking down large molecules into smaller ones?
It provides energy coupling between exergonic and endergonic reactions
Why is ATP an important molecule in metabolism?
