Chapter 8A Flashcards
What is true of metabolism in its entirety in all organisms?
Metabolism consists of all the energy transformation reactions in an organism.
Why cant cells harness heat to perform work?
temperature is usually uniform throughout a cell
A decrease in entropy is associated with which type of reaction?
dehydration
What statement is consistent with the second law of thermodynamics?
A constant input of energy is required to maintain the high level of cellular organization.
What reaction would decrease entropy?
anabolic reactions
What statement about the evolution of life on Earth, from simple prokaryote-like cells to multicellular eukaryotic organisms, is true?
It has occurred in accordance with the laws of thermodynamics and resulted in a substantial
decrease in the entropy of the planet.
A chemical reaction that has a positive ∆G is..
endergonic
What statement describes a central role that ATP plays in cellular metabolism?
ATP provides energy coupling between exergonic and endergonic reactions
Why is the ΔG of ATP hydrolysis in the cell about twice as great as the ΔG of ATP
hydrolysis in a test tube under standard conditions?
Reactant and product concentrations in the test tube are different from those in the cell.
What molecule is most similar in structure to ATP?
RNA Nucleotide
What is true when comparing an uncatalyzed reaction to the same reaction
with a catalyst?
The catalyzed reaction will have the same ΔG.
During a laboratory experiment, you discover that an enzyme-catalyzed reaction has a ΔG of -20 kcal/mol. If you double the amount of enzyme in the reaction, what will be the ΔG for the new reaction?
-20 kcal/mol
How does a noncompetitive inhibitor decrease the rate of an enzyme-catalyzed reaction?
by binding to an allosteric site, thus changing the shape of the active site of the enzyme
How might a change of one amino acid at a site, distant from the active site of an enzyme, alter the substrate specificity of an enzyme?
by changing the three-dimensional conformation of the enzyme
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.
