Chapter 8 Test Flashcards
Which term best describes the process of breaking down large molecules into smaller ones
Catabolism
What is true for anabolic pathways
They consume energy to build up polymers from monomers
What is a statement of the first law of thermodynamics
Energy can not be created or destroyed
What is an important consequence for the first law of thermodynamics in living organisms
The organism must obtain all of the necessary energy for life from its environment
How does living organisms increasing in complexity as they grow (resulting in a decrease in entropy of an organism) connect to the second law of thermodynamics
As a consequence of growing, organisms cause a greater increase in entropy in their environment than the disease in entropy associated with their growth
Whenever energy is transformed there is always an increase in the
Entropy of the universe
What is a logical consequence of the second law of thermodynamics
Every chemical reaction must increase the total entropy of the universe
What is representative of the second law of thermodynamics
Cells require a constant input of energy to maintain their high level of organization
What is a type of reaction that would decrease the entropy within a cell
Anabolic reaction
Biological evolution of life on Earth, from simple prokaryotic like cells to large, multicellular eukaryotic organisms has…
Occurred in accordance with the laws of thermodynamics
Which of the following is an example of potential rather than kinetic energy
A molecule of glucose
Which of the following is the smallest closed system
The universe
Which of the following is true of metabolism in its entirety in all organisms
Metabolism consists of all the energy transformation reactions in an organism
The mathematical expression tor the change in free energy of a system is: Delta G= Delta H - T Delta S, what is true
Delta G is the change in free energy
A system of chemical equilibrium…
Can do no work
Which of the following is true for all exergonic reactions
The reaction proceeds with a net release of free energy
What could be an example of a reaction at chemical equilibrium in a cell?
A chemical reaction in which both the reactants and products are not being produced or used in any active metabolic pathway
What are the correct changes in thermo dynamic properties for a chemical reaction in which amino acids are linked to form a protein
+DeltaH, -DeltaS, +DeltaG
The changes in free energy, total energy, and entropy are shown by…
+DeltaG, +DeltaH, -DeltaS
A chemical reaction that has a positive DeltaG is correctly described as…
Endergonic
Which of the following best describes enthalpy
The heat content of a chemical system
Why is ATP an important molecule metabolism
It provides energy coupling between exergonic and endergonic reactions
Which of the following is most similar in structure to ATP
An RNA molecule
What statement is true concerning catabolic pathways
They supply energy, primarily in the form of ATP, for the cell’s work
When chemical, transport, or mechanical work is done by an organism, what happens to the heat generated
It is lost to the environment
What purpose does it serve when ATP releases energy and inorganic phosphate
The phosphate may be incorporated into any molecule that contains phosphate
What is the difference (if any) between the structure of ATP and the structure of the precursor of the A nucleotide in RNA
There is no difference
Which of the following statements is true about enzyme catalyzed reactions
The reaction is faster than the same reaction in the absence of the enzyme
Reactants capable of interacting to form products in a chemical reaction must first overcome a thermodynamic barrier known as the reaction’s…
Activation energy
A solution of starch at room temperature does not readily decompose to form a solution of simple sugars because…
The activation energy barrier for this reaction can nit be surmounted
What is true about enzymes
They increase the rate of a reaction by lowering the activation energy barrier
The active sit of an enzyme is the region that
Binds allosteric regulators of the enzyme
What is correct about the induced fit hypothesis if enzyme caralysis
The binding of the substrate changes the shape of the enzyme’s active site
Mutations that result in single amino acid substitutions un an enzyme…
May affect the physicochemical properties of the enzyme such as temp and pH
Increasing the substrate concentration in an enzymatic reaction could overcome which of the following
Competitive inhibition
What is true about enzymes
Enzymes increase the rate of chemical reactions by lowering activation energy barriers
Zinc present in carboxypeptidase most likely functions as
Cofactor necessary for enzyme activity
How does a noncompetitive inhibitor decrease the rate if an enzyme reaction
By binding at the active site of the enzyme
What is the mechanism in which the end product of a metabolic pathway inhibits an earlier step in the pathway called
Feedback inhibition
Description of enzyme cooperativity
A substrate molecule bound to an active site if one subunit promotes substrate binding to the active site of other subunits
Allosteric enzyme regulation us usually associated with
An enzyme with more than one subunit
What is an example of cooperativity
A molecule binding at one unit of tetramer, allowing faster binding st each of the other three
What other means does a cell use to control enzymatic activity
Localization of enzymes into specific organelles or membranes
What properties must phospholipases that cleave the head groups of phospholipids exibit
Water solubility
How might an amino acid change at a site distant from the active site of the enzyme alter the enzyme’s substrate specificity
By changing the shape of the protien
