Reactions that release free energy are
exergonic
spontaneous
endergonic
endothermic
both a and b
Enzymes speed up reactions by
providing chemical energy to fuel a reaction
lowering the activation energy necessary to initiate the reaction
causing an endergonic reaction to become an exergonic reaction
substituting one of the reactants necessary for the reaction
none of the above
For the idealized reaction aA + bB === cC + dD, suppose that the equilibrium constant Keq, is 0.01. If the starting concentration for A,B,C, and D are 1 M each, what would you predict will happen based on the value of Keq?
The forward reaction is favored
The reverse reaction is favored
The forward reaction is fast
The reverse reaction is fast
Both b and d are correct
Researchers analyzed a cell extract-- a mixture of molecules isolated from cells-- and studied a chemical reaction in which a carbohydrate was broken down into smaller molecules. When they added a protease to the cell extract, the discovered that the protease greatly inhibited the rate of the reaction. Based on this observation, you could conclude that the reaction is
catalyzed by an enzyme
catalyzed by a ribozyme
Both b an dc are true of this reaction
In biological systems, ATP functions by
providing the energy to drive endergonic reactions
acting as an enzyme and lowering the activation energy of certain reactions
adjusting the pH of solutions to maintain optimal conditions for enzyme activity
regulating the speed at which endergonic reactions proceed
interacting with enzymes as a cofactor to stimulate chemical reactions
In a chemical reaction, NADH is converted to NAD+ plus H+. W easy that NADH has been
reduced
phosphorylated
oxidized
decarboxylated
methylated
Currently, scientists are identifying proteins that use ATP as an energy source by
determining whether those proteins function in anabolic or catabolic reactions
determine is the protein has a known ATP-binding site
predicting the free energy necessary for the protein to function
determining if the protein has an ATP synthase subunit
all of the above
For a particular chemical reaction, an inhibitor raises the Km, but does not affect the Vmax. This inhibitor
is a competitive inhibitor
is a noncompetitive inhibitor
binds to the active site of the enzyme
binds to an allosteric site of the enzyme
is a competitive inhibitor and binds to the active site of the enzyme
Which of the following is (are) key benefits of catabolic reactions?
Recycling of organic building blocks
Breakdown of organic molecules to obtain energy
Synthesis of important polymers, such as polypeptides
All of the above
a and b only
Autophagy provides a way for cells to
degrade entire organelles and cycle their components
control the level of ATP
engulf bacterial cells
export unwanted organelles out of the cell
inhibit the first enzyme in a metabolic pathway
