quiz six (2)
Which of the following statements comparing allosteric regulators and non-competitive inhibitors is FALSE?
Allosteric regulators always inhibit (decrease) the activity levels of the enzymes they regulate.
Which of the following statements comparing allosteric regulators and non-competitive inhibitors is TRUE
Allosteric regulators may increase or decrease an enzyme's activity level.
Living organisms increase in complexity as they grow, resulting in a decrease in the entropy of an organism. How does this relate to the second law of thermodynamics?
As a consequence of growing, organisms create more disorder in their environment than the decrease in entropy associated with their growth.
Which of the following statements about bases is FALSE?
Bases cause the pH of the solution to decrease.
What is the difference between covalent bonds and ionic bonds?
Covalent bonds involve the sharing of electrons between atoms; ionic bonds involve the electrical attraction between atoms.
Which of the following statements about enzymes is FALSE?
Enzymes increase the free energy of the reactants.
Which of the following is a statement of the second law of thermodynamics?
Every energy transfer or transformation increases the entropy of the universe
The molecules shown below are best described as
Structural isomers
A solution of protein at room temperature does not readily decompose to form a solution of amino acids because
The activation energy barrier cannot be surmounted.
Polar molecules are often able to dissolve in water because
The partially charged regions of polar molecules are able to form hydrogen bonds with water molecules.
When you have a severe fever, what may be a grave consequence if this is not controlled?
changes in the folding of enzymes
L-methionine and D-methionine are examples of
enantiomers
Desmosomes function to
fasten cells together into strong sheets
A series of enzymes catalyzes the series of reactions shown below. Product A binds to the enzyme that converts X to Y at a position remote from its active site. This binding decreases the activity of the enzyme. Substance A functions in
feedback inhibition
The lowest energy mechanism by which a carbon atom may complete its valence shell is to
form 4 covalent bonds with other atoms
Molecules consisting only of carbon and hydrogen are known as
hydrocarbon
The primary structure of a protein refers to
its amino acid sequence
Feedback inhibition is used by cells to
keep from producing unnecessarily high levels of different products.
Which structure is the site of the synthesis of protein that may be exported from the cell?
rough endoplasmic reticulum
Which of the following statements about electrons is FALSE
the closer an electron is to the nucleus, the more strongly the electron is attracted to the nucleus and therefore the more potential energy the electron has
The hydrolysis of ATP: ATP + H2O → ADP + Pi is exergonic, with a ∆G of -7.3 kcal/mol under standard conditions. What is the source of the 7.3 kcal/mol released in this reaction?
the difference between the potential energy in the bonds of ATP and the water molecule, minus the potential energy in the bonds of ADP and Pi. In other words: (potential energy in bonds of ATP + potential energy in bonds of H2O) - (potential energy in bonds of ADP + potential energy in bonds of Pi) = 7.3 kcal/mol
Cotransporters
transport two different types of molecules, with one moving down its concentration or electrochemical gradient and the other moving up
The mathematical expression for the change in the free energy of a system is ∆G = ∆H - T∆S. Which of the following is (are) TRUE?
∆H is the change in enthalpy.
Which of the following are TRUE for anabolic pathways?
They consume energy to build up polymers from monomers
For the reaction described in the figure shown below, which of the following represents the activation energy barrier for the enzyme-catalyzed reaction?
arrow B
For the reaction described in the figure shown below, which of the following represents the difference between the free energy content of the reactants and the free energy content of the products?
arrow D
A consequence of the fact that Gibb's free energy must decrease in a spontaneous reaction is
that a given reaction may proceed spontaneously in both directions, due to the fact that different reactant and product molecules will have slightly different energies.
Which of the following most accurately describe kinetic and potential energy?
kinetic energy is due to movement and potential energy is energy that is stored in matter that is not due to movement
A lipid molecule that starts on the inside face of the ER membrane (i.e. the side of the ER membrane that is NOT in contact with the cytosol) and is then transported to the plasma membrane will
most likely end up on the outside (extracellular) face of the plasma membrane
When a hydrogen ion (= a proton) enters a cell, it is
moving down its electrochemical gradient as the hydrogen ion concentration is greater outside of cells and the outsides of cells are positively charged relative to the insides
They are usually coupled with anabolic pathways to which they supply energy in the form of ATP.
no
Which of the following is an example of qualitative data?
The fish swam in a zigzag motion.
Which of the following statements about valence shells is FALSE?
The number of valence shells contained by a particular atom is dependent on how many electrons that atom has.
Which of the following statements concerning catabolic pathways is TRUE?
They are usually coupled with anabolic pathways to which they supply energy in the form of ATP.
During peer-review of a manuscript
(a) the experiments described in the manuscript are evaluated to determine whether they were rigorously performed (b) typically two to three experts review the manuscript (c) the conclusions drawn in the manuscript are carefully considered to determine whether they are adequately supported by the data
Which of the following is a statement of the first law of thermodynamics?
Energy cannot be created or destroyed
Which pathway is generally followed by a lipid molecule for incorporation in the endomembrane system?
Smooth ER and/or rough ER, vesicle, Golgi, vesicle
Bound ribosomes
all of these answers are correct
Which of the following help form the tertiary structure of a protein?
all of these answers are correct
"Conservation of energy" is another way of stating
the first law of thermodynamics
